diff --git a/.eslintrc b/.eslintrc
index df9d7d57..fd6d4a88 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -6,7 +6,7 @@
   "parserOptions": {
     "sourceType": "module"
   },
-  "plugins": ["compat", "qunit", "testcafe", "jsdoc", "markdown"],
+  "plugins": ["compat", "qunit", "testcafe", "jsdoc", "markdown", "import", "node", "promise"],
   "env": {
     "node": false,
     "browser": true
@@ -26,24 +26,296 @@
       "allowAugmentsExtendsWithoutParam": true
     }
   },
-  "overrides": [{
-    "files": ["**/*.md"],
-    "rules": {
-      "no-undef": ["off"],
-      "no-unused-vars": ["warn"],
-      "padded-blocks": ["off"]
+  "overrides": [
+    {
+      "files": ["editor/locale/lang.*.js"],
+      "rules": {
+        "import/no-anonymous-default-export": ["off"]
+      }
+    },
+    {
+      "files": ["editor/extensions/ext-locale/**"],
+      "rules": {
+        "import/no-anonymous-default-export": ["off"]
+      }
+    },
+    {
+      "files": ["editor/extensions/**/ext-*.js"],
+      "rules": {
+        "consistent-this": ["error", "svgEditor"],
+        "import/no-anonymous-default-export": ["off"]
+      }
+    },
+    {
+      "files": [
+        "editor/svgpathseg.js", "editor/touch.js", "editor/typedefs.js",
+        "editor/redirect-on-no-module-support.js",
+        "test/all_tests.js", "screencasts/svgopen2010/script.js",
+        "opera-widget/handlers.js",
+        "firefox-extension/handlers.js",
+        "firefox-extension/content/svg-edit-overlay.js"
+      ],
+      "rules": {
+        "import/unambiguous": ["off"]
+      }
+    },
+    {
+      "files": ["**/*.md"],
+      "rules": {
+        "no-undef": ["off"],
+        "no-unused-vars": ["warn"],
+        "padded-blocks": ["off"],
+        "import/unambiguous": ["off"]
+      }
+    },
+    {
+      "files": ["test/**"],
+      "rules": {
+        "no-console": ["off"]
+      }
+    },
+    {
+      "files": [
+        "docs/jsdoc-config.js", "build-html.js", "jsdoc-check-overly-generic-types.js",
+        "rollup.config.js", "rollup-config.config.js"
+      ],
+      "rules": {
+        "node/no-extraneous-import": ["error"],
+        "node/no-extraneous-require": ["error"],
+        "node/no-missing-import": ["error"],
+        "node/no-missing-require": ["error"],
+        "node/no-unpublished-bin": ["error"],
+        "node/no-unpublished-import": ["error"],
+        "node/no-unpublished-require": ["error"],
+        "node/no-unsupported-features/es-builtins": ["error"],
+        "node/no-unsupported-features/es-syntax": ["error"],
+        "node/no-unsupported-features/node-builtins": ["error"],
+        "node/process-exit-as-throw": ["error"],
+        "node/shebang": ["error"],
+
+        "node/exports-style": ["error", "module.exports"],
+        "node/prefer-global/buffer": ["error", "always"],
+        "node/prefer-global/console": ["error", "always"],
+        "node/prefer-global/process": ["error", "always"],
+        "node/prefer-global/text-decoder": ["error", "always"],
+        "node/prefer-global/text-encoder": ["error", "always"],
+        "node/prefer-global/url-search-params": ["error", "always"],
+        "node/prefer-global/url": ["error", "always"]
+      }
+    },
+    {
+      "files": ["rollup.config.js", "rollup-config.config.js"],
+      "rules": {
+        "node/no-unsupported-features/es-syntax": "off",
+        "node/no-unpublished-import": "off"
+      }
+    },
+    {
+      "files": ["jsdoc-check-overly-generic-types.js", "build-html.js"],
+      "rules": {
+        "import/unambiguous": "off",
+        "import/no-commonjs": "off"
+      }
     }
-  }],
+  ],
   "rules": {
-    "semi": [2, "always"],
+    "array-bracket-newline": ["error", "consistent"],
+    "array-bracket-spacing": ["error"],
+    "array-callback-return": ["error"],
+    "array-element-newline": ["off"],
+    "arrow-body-style": ["off"],
+    "arrow-parens": ["error"],
+    "block-scoped-var": ["error"],
+    "callback-return": ["error"],
+    "class-methods-use-this": ["warn"],
+    "computed-property-spacing": ["error"],
+    "consistent-return": ["error"],
+    "consistent-this": ["warn"],
+    "dot-notation": ["error"],
+    "for-direction": ["error"],
+    "func-name-matching": ["error"],
+    "func-names": ["off"],
+    "func-style": ["off"],
+    "function-paren-newline": ["error", "consistent"],
+    "getter-return": ["error"],
+    "global-require": ["error"],
+    "guard-for-in": ["error"],
+    "id-blacklist": ["off"],
+    "id-length": ["off"],
+    "id-match": ["off"],
+    "implicit-arrow-linebreak": ["error"],
+    "init-declarations": ["off"],
+    "jsx-quotes": ["error"],
+    "line-comment-position": ["off"],
+    "linebreak-style": ["error"],
+    "lines-around-comment": ["off"],
+    "lines-between-class-members": ["off"],
+    "max-classes-per-file": ["off"],
+    "max-depth": ["off"],
+    "max-lines-per-function": ["off"],
+    "max-lines": ["off"],
+    "max-nested-callbacks": ["error"],
+    "max-params": ["off"],
+    "max-statements-per-line": ["off"],
+    "max-statements": ["off"],
+    "multiline-comment-style": ["off"],
+    "multiline-ternary": ["error", "always-multiline"],
+    "newline-after-var": ["off"],
+    "newline-before-return": ["off"],
+    "newline-per-chained-call": ["off"],
+    "no-alert": ["warn"],
+    "no-async-promise-executor": ["error"],
+    "no-await-in-loop": ["error"],
+    "no-bitwise": ["error"],
+    "no-buffer-constructor": ["error"],
+    "no-case-declarations": ["error"],
+    "no-confusing-arrow": ["error"],
+    "no-console": ["warn"],
+    "no-continue": ["off"],
+    "no-div-regex": ["error"],
+    "no-duplicate-imports": ["error"],
+    "no-else-return": ["error"],
+    "no-empty-function": ["warn"],
+    "no-empty": ["error", {"allowEmptyCatch": true}],
+    "no-eq-null": ["error"],
+    "no-extra-label": ["error"],
+    "no-extra-semi": ["error"],
+    "no-implicit-coercion": ["error"],
+    "no-implicit-globals": ["error"],
+    "no-inline-comments": ["off"],
+    "no-invalid-this": ["off"],
+    "no-lonely-if": ["error"],
+    "no-loop-func": ["error"],
+    "no-misleading-character-class": ["error"],
+    "no-mixed-requires": ["error", {"grouping": true, "allowCall": true}],
+    "no-multi-assign": ["off"],
+    "no-negated-condition": ["off"],
+    "no-nested-ternary": ["off"],
+    "no-param-reassign": ["off"],
+    "no-plusplus": ["off"],
+    "no-process-env": ["error"],
+    "no-process-exit": ["error"],
+    "no-prototype-builtins": ["error"],
+    "no-restricted-globals": ["error", {
+        "name": "event",
+        "message": "Use local event parameter instead (preferably as \"e\" or \"ev\")."
+    }, {
+        "name": "fdescribe",
+        "message": "Do not commit fdescribe. Use describe instead."
+    }],
+    "no-restricted-imports": ["off"],
+    "no-restricted-modules": ["off"],
+    "no-restricted-properties": ["error", {
+        "property": "__defineGetter__",
+        "message": "Please use `Object.defineProperty` instead."
+    }],
+    "no-restricted-syntax": ["off"],
+    "no-script-url": ["error"],
+    "no-shadow": ["error", {"builtinGlobals": true, "hoist": "functions", "allow": ["parent", "top", "open", "name", "closed", "start"]}],
+    "no-spaced-func": ["error"],
+    "no-sync": ["error"],
+    "no-ternary": ["off"],
+    "no-undefined": ["off"],
+    "no-underscore-dangle": ["off"],
+    "no-unused-labels": ["error"],
+    "no-useless-concat": ["off"],
+    "no-var": ["error"],
+    "no-void": ["error"],
+    "nonblock-statement-body-position": ["error"],
+    "object-curly-newline": ["off"],
+    "object-shorthand": ["error", "always", {"avoidExplicitReturnArrows": true}],
+    "one-var-declaration-per-line": ["off"],
+    "operator-assignment": ["error"],
+    "padding-line-between-statements": ["off"],
+    "prefer-arrow-callback": ["off"],
+    "prefer-const": ["error"],
+    "prefer-destructuring": ["error", {"object": true}],
+    "prefer-numeric-literals": ["warn"],
+    "prefer-object-spread": ["error"],
+    "prefer-rest-params": ["error"],
+    "prefer-spread": ["error"],
+    "prefer-template": ["off"],
+    "quote-props": ["error", "as-needed"],
+    "radix": ["error", "as-needed"],
+    "require-atomic-updates": ["error"],
+    "require-await": ["error"],
+    "require-jsdoc": ["warn"],
+    "require-yield": ["error"],
+    "semi-style": ["error"],
+    "sort-imports": ["off"],
+    "sort-keys": ["off"],
+    "sort-vars": ["off"],
+    "strict": ["error"],
+    "switch-colon-spacing": ["error"],
+    "vars-on-top": ["warn"],
+    "wrap-regex": ["error"],
+
+    "semi": ["error", "always"],
     "indent": ["error", 2, {"outerIIFEBody": 0}],
-    "object-property-newline": 0,
-    "one-var": 0,
-    "no-var": 2,
-    "prefer-const": 2,
-    "no-extra-semi": 2,
-    "quote-props": [2, "as-needed"],
+    "object-property-newline": ["off"],
+    "one-var": ["off"],
     "object-curly-spacing": ["error", "never"],
+
+    "promise/catch-or-return": "error",
+    "promise/no-return-wrap": "error",
+    "promise/param-names": "error",
+    "promise/always-return": "error",
+    "promise/no-native": "off",
+    "promise/no-nesting": "warn",
+    "promise/no-promise-in-callback": "warn",
+    "promise/no-callback-in-promise": "warn",
+    "promise/avoid-new": "warn",
+    "promise/no-new-statics": "error",
+    "promise/no-return-in-finally": "warn",
+    "promise/valid-params": "warn",
+    "promise/prefer-await-to-then": "error",
+    "promise/prefer-await-to-callbacks": "warn",
+
+    "import/no-unresolved": "error",
+    "import/named": "error",
+    "import/default": "error",
+    "import/namespace": "error",
+    "import/no-restricted-paths": "off",
+    "import/no-absolute-path": "error",
+    "import/no-dynamic-require": "error",
+    "import/no-internal-modules": "off",
+    "import/no-webpack-loader-syntax": "error",
+    "import/no-self-import": "error",
+    "import/no-cycle": "off",
+    "import/no-useless-path-segments": "error",
+    "import/no-relative-parent-imports": "off",
+    "import/export": "error",
+    "import/no-named-as-default": "error",
+    "import/no-named-as-default-member": "error",
+    "import/no-deprecated": "error",
+    "import/no-extraneous-dependencies": "error",
+    "import/no-mutable-exports": "error",
+    "import/unambiguous": "warn",
+    "import/no-commonjs": "error",
+    "import/no-amd": "error",
+    "import/no-nodejs-modules": "off",
+    "import/first": "error",
+    "import/exports-last": "off",
+    "import/no-duplicates": "error",
+    "import/no-namespace": "off",
+    "import/extensions": ["error", "always", {"ignorePackages": true}],
+    "import/order": ["error", {"groups": [
+      "builtin",
+      "external",
+      "internal",
+      ["parent", "sibling", "index"]
+    ]}],
+    "import/newline-after-import": "error",
+    "import/prefer-default-export": "off",
+    "import/max-dependencies": "off",
+    "import/no-unassigned-import": "off",
+    "import/no-named-default": "error",
+    "import/no-default-export": "off",
+    "import/no-named-export": "off",
+    "import/no-anonymous-default-export": "error",
+    "import/group-exports": "off",
+    "import/dynamic-import-chunkname": "off",
+
     "jsdoc/check-param-names": 1,
     "jsdoc/check-tag-names": 1,
     "jsdoc/check-types": 1,
@@ -61,7 +333,7 @@
 
     "jsdoc/no-undefined-types": ["off"],
     "jsdoc/valid-types": ["error"],
-    "valid-jsdoc": ["off", {
+    "valid-jsdoc": ["error", {
         "prefer": {
             "arg": "param",
             "argument": "param",
@@ -81,6 +353,16 @@
         "matchDescription": "^([A-Z][\\s\\S]*[.`?!])?$",
         "requireParamDescription": false,
         "requireReturnDescription": false
+    }],
+    "no-warning-comments": ["off"],
+    "default-case": ["off"],
+    "complexity": ["off"],
+    "require-unicode-regexp": ["off"],
+    "capitalized-comments": ["off"],
+    "no-magic-numbers": ["off"],
+    "max-len": ["off", {
+      "ignoreUrls": true,
+      "ignoreRegExpLiterals": true
     }]
   }
 }
diff --git a/editor/browser.js b/editor/browser.js
index b21e1bd5..747da58b 100644
--- a/editor/browser.js
+++ b/editor/browser.js
@@ -16,7 +16,7 @@ import {NS} from './namespaces.js';
 const $ = jQuery;
 
 const supportsSVG_ = (function () {
-return !!document.createElementNS && !!document.createElementNS(NS.SVG, 'svg').createSVGRect;
+return Boolean(document.createElementNS && document.createElementNS(NS.SVG, 'svg').createSVGRect);
 }());
 
 /**
@@ -29,7 +29,7 @@ const {userAgent} = navigator;
 const svg = document.createElementNS(NS.SVG, 'svg');
 
 // Note: Browser sniffing should only be used if no other detection method is possible
-const isOpera_ = !!window.opera;
+const isOpera_ = Boolean(window.opera);
 const isWebkit_ = userAgent.includes('AppleWebKit');
 const isGecko_ = userAgent.includes('Gecko/');
 const isIE_ = userAgent.includes('MSIE');
@@ -39,11 +39,11 @@ const isMac_ = userAgent.includes('Macintosh');
 const isTouch_ = 'ontouchstart' in window;
 
 const supportsSelectors_ = (function () {
-return !!svg.querySelector;
+return Boolean(svg.querySelector);
 }());
 
 const supportsXpath_ = (function () {
-return !!document.evaluate;
+return Boolean(document.evaluate);
 }());
 
 // segList functions (for FF1.5 and 2.0)
diff --git a/editor/canvg/canvg.js b/editor/canvg/canvg.js
index f5a09937..5bf8039b 100644
--- a/editor/canvg/canvg.js
+++ b/editor/canvg/canvg.js
@@ -11,6 +11,15 @@
 import RGBColor from './rgbcolor.js';
 import {canvasRGBA} from '../external/stackblur-canvas/dist/stackblur-es.js';
 
+/**
+ * Whether a value is `null` or `undefined`.
+ * @param {Any} val
+ * @returns {boolean}
+ */
+const isNullish = (val) => {
+  return val === null || val === undefined;
+};
+
 let canvasRGBA_ = canvasRGBA;
 
 /**
@@ -63,7 +72,7 @@ export const setStackBlurCanvasRGBA = (cb) => {
 */
 export const canvg = function (target, s, opts) {
   // no parameters
-  if (target == null && s == null && opts == null) {
+  if (isNullish(target) && isNullish(s) && isNullish(opts)) {
     const svgTags = document.querySelectorAll('svg');
     return Promise.all([...svgTags].map((svgTag) => {
       const c = document.createElement('canvas');
@@ -82,7 +91,7 @@ export const canvg = function (target, s, opts) {
   }
 
   // store class on canvas
-  if (target.svg != null) target.svg.stop();
+  if (!isNullish(target.svg)) target.svg.stop();
   const svg = build(opts || {});
   // on i.e. 8 for flash canvas, we can't assign the property so check for it
   if (!(target.childNodes.length === 1 && target.childNodes[0].nodeName === 'OBJECT')) {
@@ -113,9 +122,9 @@ function build (opts) {
   svg.FRAMERATE = 30;
   svg.MAX_VIRTUAL_PIXELS = 30000;
 
-  svg.log = function (msg) {};
+  svg.log = function (msg) { /* */ };
   if (svg.opts.log === true && typeof console !== 'undefined') {
-    svg.log = function (msg) { console.log(msg); };
+    svg.log = function (msg) { console.log(msg); }; // eslint-disable-line no-console
   }
 
   // globals
@@ -139,7 +148,7 @@ function build (opts) {
       width () { return this.Current().width; },
       height () { return this.Current().height; },
       ComputeSize (d) {
-        if (d != null && typeof d === 'number') return d;
+        if (!isNullish(d) && typeof d === 'number') return d;
         if (d === 'x') return this.width();
         if (d === 'y') return this.height();
         return Math.sqrt(
@@ -190,13 +199,12 @@ function build (opts) {
     if (window.DOMParser) {
       const parser = new DOMParser();
       return parser.parseFromString(xml, 'text/xml');
-    } else {
-      xml = xml.replace(/<!DOCTYPE svg[^>]*>/, '');
-      const xmlDoc = new window.ActiveXObject('Microsoft.XMLDOM');
-      xmlDoc.async = 'false';
-      xmlDoc.loadXML(xml);
-      return xmlDoc;
     }
+    xml = xml.replace(/<!DOCTYPE svg[^>]*>/, '');
+    const xmlDoc = new window.ActiveXObject('Microsoft.XMLDOM');
+    xmlDoc.async = 'false';
+    xmlDoc.loadXML(xml);
+    return xmlDoc;
   };
 
   // text extensions
@@ -226,7 +234,7 @@ function build (opts) {
     }
 
     hasValue () {
-      return (this.value != null && this.value !== '');
+      return (!isNullish(this.value) && this.value !== '');
     }
 
     // return the numerical value of the property
@@ -234,8 +242,8 @@ function build (opts) {
       if (!this.hasValue()) return 0;
 
       let n = parseFloat(this.value);
-      if ((this.value + '').match(/%$/)) {
-        n = n / 100.0;
+      if (String(this.value).match(/%$/)) {
+        n /= 100.0;
       }
       return n;
     }
@@ -254,7 +262,7 @@ function build (opts) {
     // augment the current color value with the opacity
     addOpacity (opacityProp) {
       let newValue = this.value;
-      if (opacityProp.value != null && opacityProp.value !== '' && typeof this.value === 'string') { // can only add opacity to colors, not patterns
+      if (!isNullish(opacityProp.value) && opacityProp.value !== '' && typeof this.value === 'string') { // can only add opacity to colors, not patterns
         const color = new RGBColor(this.value);
         if (color.ok) {
           newValue = 'rgba(' + color.r + ', ' + color.g + ', ' + color.b + ', ' + opacityProp.numValue() + ')';
@@ -280,12 +288,12 @@ function build (opts) {
       let def = this.getDefinition();
 
       // gradient
-      if (def != null && def.createGradient) {
+      if (!isNullish(def) && def.createGradient) {
         return def.createGradient(svg.ctx, e, opacityProp);
       }
 
       // pattern
-      if (def != null && def.createPattern) {
+      if (!isNullish(def) && def.createPattern) {
         if (def.getHrefAttribute().hasValue()) {
           const pt = def.attribute('patternTransform');
           def = def.getHrefAttribute().getDefinition();
@@ -312,14 +320,13 @@ function build (opts) {
     }
 
     getUnits () {
-      const s = this.value + '';
-      return s.replace(/[0-9.-]/g, '');
+      return String(this.value).replace(/[0-9.-]/g, '');
     }
 
     // get the length as pixels
     toPixels (viewPort, processPercent) {
       if (!this.hasValue()) return 0;
-      const s = this.value + '';
+      const s = String(this.value);
       if (s.match(/em$/)) return this.numValue() * this.getEM(viewPort);
       if (s.match(/ex$/)) return this.numValue() * this.getEM(viewPort) / 2.0;
       if (s.match(/px$/)) return this.numValue();
@@ -338,7 +345,7 @@ function build (opts) {
     // get the time as milliseconds
     toMilliseconds () {
       if (!this.hasValue()) return 0;
-      const s = this.value + '';
+      const s = String(this.value);
       if (s.match(/s$/)) return this.numValue() * 1000;
       if (s.match(/ms$/)) return this.numValue();
       return this.numValue();
@@ -348,7 +355,7 @@ function build (opts) {
     // get the angle as radians
     toRadians () {
       if (!this.hasValue()) return 0;
-      const s = this.value + '';
+      const s = String(this.value);
       if (s.match(/deg$/)) return this.numValue() * (Math.PI / 180.0);
       if (s.match(/grad$/)) return this.numValue() * (Math.PI / 200.0);
       if (s.match(/rad$/)) return this.numValue();
@@ -368,7 +375,7 @@ function build (opts) {
     Weights: 'normal|bold|bolder|lighter|100|200|300|400|500|600|700|800|900|inherit',
 
     CreateFont (fontStyle, fontVariant, fontWeight, fontSize, fontFamily, inherit) {
-      const f = inherit != null ? this.Parse(inherit) : this.CreateFont('', '', '', '', '', svg.ctx.font);
+      const f = !isNullish(inherit) ? this.Parse(inherit) : this.CreateFont('', '', '', '', '', svg.ctx.font);
       return {
         fontFamily: fontFamily || f.fontFamily,
         fontSize: fontSize || f.fontSize,
@@ -474,7 +481,7 @@ function build (opts) {
     height () { return this.y2 - this.y1; }
 
     addPoint (x, y) {
-      if (x != null) {
+      if (!isNullish(x)) {
         if (isNaN(this.x1) || isNaN(this.x2)) {
           this.x1 = x;
           this.x2 = x;
@@ -483,7 +490,7 @@ function build (opts) {
         if (x > this.x2) this.x2 = x;
       }
 
-      if (y != null) {
+      if (!isNullish(y)) {
         if (isNaN(this.y1) || isNaN(this.y2)) {
           this.y1 = y;
           this.y2 = y;
@@ -710,7 +717,7 @@ function build (opts) {
     else if (meetOrSlice === 'slice') ctx.scale(scaleMax, scaleMax);
 
     // translate
-    ctx.translate(minX == null ? 0 : -minX, minY == null ? 0 : -minY);
+    ctx.translate(isNullish(minX) ? 0 : -minX, isNullish(minY) ? 0 : -minY);
   };
 
   // elements
@@ -724,7 +731,7 @@ function build (opts) {
       this.attributes = {};
       this.styles = {};
       this.children = [];
-      if (node != null && node.nodeType === 1) { // ELEMENT_NODE
+      if (!isNullish(node) && node.nodeType === 1) { // ELEMENT_NODE
         // add children
         [...node.childNodes].forEach((childNode) => {
           if (childNode.nodeType === 1) {
@@ -749,7 +756,7 @@ function build (opts) {
         });
         // add tag styles
         let styles = svg.Styles[node.nodeName];
-        if (styles != null) {
+        if (!isNullish(styles)) {
           for (const name in styles) {
             this.styles[name] = styles[name];
           }
@@ -760,13 +767,13 @@ function build (opts) {
           const classes = svg.compressSpaces(this.attribute('class').value).split(' ');
           classes.forEach((clss) => {
             styles = svg.Styles['.' + clss];
-            if (styles != null) {
+            if (!isNullish(styles)) {
               for (const name in styles) {
                 this.styles[name] = styles[name];
               }
             }
             styles = svg.Styles[node.nodeName + '.' + clss];
-            if (styles != null) {
+            if (!isNullish(styles)) {
               for (const name in styles) {
                 this.styles[name] = styles[name];
               }
@@ -777,7 +784,7 @@ function build (opts) {
         // add id styles
         if (this.attribute('id').hasValue()) {
           const styles = svg.Styles['#' + this.attribute('id').value];
-          if (styles != null) {
+          if (!isNullish(styles)) {
             for (const name in styles) {
               this.styles[name] = styles[name];
             }
@@ -799,7 +806,7 @@ function build (opts) {
 
         // add id
         if (this.attribute('id').hasValue()) {
-          if (svg.Definitions[this.attribute('id').value] == null) {
+          if (isNullish(svg.Definitions[this.attribute('id').value])) {
             svg.Definitions[this.attribute('id').value] = this;
           }
         }
@@ -809,7 +816,7 @@ function build (opts) {
     // get or create attribute
     attribute (name, createIfNotExists) {
       let a = this.attributes[name];
-      if (a != null) return a;
+      if (!isNullish(a)) return a;
 
       if (createIfNotExists === true) { a = new svg.Property(name, ''); this.attributes[name] = a; }
       return a || svg.EmptyProperty;
@@ -827,19 +834,19 @@ function build (opts) {
     // get or create style, crawls up node tree
     style (name, createIfNotExists, skipAncestors) {
       let s = this.styles[name];
-      if (s != null) return s;
+      if (!isNullish(s)) return s;
 
       const a = this.attribute(name);
-      if (a != null && a.hasValue()) {
+      if (!isNullish(a) && a.hasValue()) {
         this.styles[name] = a; // move up to me to cache
         return a;
       }
 
       if (skipAncestors !== true) {
         const p = this.parent;
-        if (p != null) {
+        if (!isNullish(p)) {
           const ps = p.style(name);
-          if (ps != null && ps.hasValue()) {
+          if (!isNullish(ps) && ps.hasValue()) {
             return ps;
           }
         }
@@ -860,10 +867,10 @@ function build (opts) {
       ctx.save();
       if (this.attribute('mask').hasValue()) { // mask
         const mask = this.attribute('mask').getDefinition();
-        if (mask != null) mask.apply(ctx, this);
+        if (!isNullish(mask)) mask.apply(ctx, this);
       } else if (this.style('filter').hasValue()) { // filter
         const filter = this.style('filter').getDefinition();
-        if (filter != null) filter.apply(ctx, this);
+        if (!isNullish(filter)) filter.apply(ctx, this);
       } else {
         this.setContext(ctx);
         this.renderChildren(ctx);
@@ -903,7 +910,7 @@ function build (opts) {
       // fill
       if (this.style('fill').isUrlDefinition()) {
         const fs = this.style('fill').getFillStyleDefinition(this, this.style('fill-opacity'));
-        if (fs != null) ctx.fillStyle = fs;
+        if (!isNullish(fs)) ctx.fillStyle = fs;
       } else if (this.style('fill').hasValue()) {
         const fillStyle = this.style('fill');
         if (fillStyle.value === 'currentColor') fillStyle.value = this.style('color').value;
@@ -918,7 +925,7 @@ function build (opts) {
       // stroke
       if (this.style('stroke').isUrlDefinition()) {
         const fs = this.style('stroke').getFillStyleDefinition(this, this.style('stroke-opacity'));
-        if (fs != null) ctx.strokeStyle = fs;
+        if (!isNullish(fs)) ctx.strokeStyle = fs;
       } else if (this.style('stroke').hasValue()) {
         const strokeStyle = this.style('stroke');
         if (strokeStyle.value === 'currentColor') strokeStyle.value = this.style('color').value;
@@ -963,7 +970,8 @@ function build (opts) {
           this.style('font-variant').value,
           this.style('font-weight').value,
           this.style('font-size').hasValue() ? this.style('font-size').toPixels() + 'px' : '',
-          this.style('font-family').value).toString();
+          this.style('font-family').value
+        ).toString();
       }
 
       // transform
@@ -975,7 +983,7 @@ function build (opts) {
       // clip
       if (this.style('clip-path', false, true).hasValue()) {
         const clip = this.style('clip-path', false, true).getDefinition();
-        if (clip != null) clip.apply(ctx);
+        if (!isNullish(clip)) clip.apply(ctx);
       }
 
       // opacity
@@ -987,7 +995,7 @@ function build (opts) {
 
   svg.Element.PathElementBase = class extends svg.Element.RenderedElementBase {
     path (ctx) {
-      if (ctx != null) ctx.beginPath();
+      if (!isNullish(ctx)) ctx.beginPath();
       return new svg.BoundingBox();
     }
 
@@ -1004,7 +1012,7 @@ function build (opts) {
       if (ctx.strokeStyle !== '') ctx.stroke();
 
       const markers = this.getMarkers();
-      if (markers != null) {
+      if (!isNullish(markers)) {
         if (this.style('marker-start').isUrlDefinition()) {
           const marker = this.style('marker-start').getDefinition();
           marker.render(ctx, markers[0][0], markers[0][1]);
@@ -1123,7 +1131,7 @@ function build (opts) {
       if (this.attribute('ry').hasValue() && !this.attribute('rx').hasValue()) rx = ry;
       rx = Math.min(rx, width / 2.0);
       ry = Math.min(ry, height / 2.0);
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.beginPath();
         ctx.moveTo(x + rx, y);
         ctx.lineTo(x + width - rx, y);
@@ -1148,7 +1156,7 @@ function build (opts) {
       const cy = this.attribute('cy').toPixels('y');
       const r = this.attribute('r').toPixels();
 
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.beginPath();
         ctx.arc(cx, cy, r, 0, Math.PI * 2, true);
         ctx.closePath();
@@ -1167,7 +1175,7 @@ function build (opts) {
       const cx = this.attribute('cx').toPixels('x');
       const cy = this.attribute('cy').toPixels('y');
 
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.beginPath();
         ctx.moveTo(cx, cy - ry);
         ctx.bezierCurveTo(cx + (KAPPA * rx), cy - ry, cx + rx, cy - (KAPPA * ry), cx + rx, cy);
@@ -1186,13 +1194,14 @@ function build (opts) {
     getPoints () {
       return [
         new svg.Point(this.attribute('x1').toPixels('x'), this.attribute('y1').toPixels('y')),
-        new svg.Point(this.attribute('x2').toPixels('x'), this.attribute('y2').toPixels('y'))];
+        new svg.Point(this.attribute('x2').toPixels('x'), this.attribute('y2').toPixels('y'))
+      ];
     }
 
     path (ctx) {
       const points = this.getPoints();
 
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.beginPath();
         ctx.moveTo(points[0].x, points[0].y);
         ctx.lineTo(points[1].x, points[1].y);
@@ -1218,14 +1227,14 @@ function build (opts) {
     path (ctx) {
       const {x, y} = this.points[0];
       const bb = new svg.BoundingBox(x, y);
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.beginPath();
         ctx.moveTo(x, y);
       }
       for (let i = 1; i < this.points.length; i++) {
         const {x, y} = this.points[i];
         bb.addPoint(x, y);
-        if (ctx != null) ctx.lineTo(x, y);
+        if (!isNullish(ctx)) ctx.lineTo(x, y);
       }
       return bb;
     }
@@ -1244,7 +1253,7 @@ function build (opts) {
   svg.Element.polygon = class extends svg.Element.polyline {
     path (ctx) {
       const bb = super.path(ctx);
-      if (ctx != null) {
+      if (!isNullish(ctx)) {
         ctx.lineTo(this.points[0].x, this.points[0].y);
         ctx.closePath();
       }
@@ -1289,7 +1298,7 @@ function build (opts) {
 
         isCommandOrEnd () {
           if (this.isEnd()) return true;
-          return this.tokens[this.i + 1].match(/^[A-Za-z]$/) != null;
+          return !isNullish(this.tokens[this.i + 1].match(/^[A-Za-z]$/));
         },
 
         isRelativeCommand () {
@@ -1363,10 +1372,10 @@ function build (opts) {
 
         addMarker (p, from, priorTo) {
           // if the last angle isn't filled in because we didn't have this point yet ...
-          if (priorTo != null && this.angles.length > 0 && this.angles[this.angles.length - 1] == null) {
+          if (!isNullish(priorTo) && this.angles.length > 0 && isNullish(this.angles[this.angles.length - 1])) {
             this.angles[this.angles.length - 1] = this.points[this.points.length - 1].angleTo(priorTo);
           }
-          this.addMarkerAngle(p, from == null ? null : from.angleTo(p));
+          this.addMarkerAngle(p, isNullish(from) ? null : from.angleTo(p));
         },
 
         addMarkerAngle (p, a) {
@@ -1377,9 +1386,9 @@ function build (opts) {
         getMarkerPoints () { return this.points; },
         getMarkerAngles () {
           for (let i = 0; i < this.angles.length; i++) {
-            if (this.angles[i] == null) {
+            if (isNullish(this.angles[i])) {
               for (let j = i + 1; j < this.angles.length; j++) {
-                if (this.angles[j] != null) {
+                if (!isNullish(this.angles[j])) {
                   this.angles[i] = this.angles[j];
                   break;
                 }
@@ -1396,7 +1405,7 @@ function build (opts) {
       pp.reset();
 
       const bb = new svg.BoundingBox();
-      if (ctx != null) ctx.beginPath();
+      if (!isNullish(ctx)) ctx.beginPath();
       while (!pp.isEnd()) {
         pp.nextCommand();
         switch (pp.command) {
@@ -1405,13 +1414,13 @@ function build (opts) {
           const p = pp.getAsCurrentPoint();
           pp.addMarker(p);
           bb.addPoint(p.x, p.y);
-          if (ctx != null) ctx.moveTo(p.x, p.y);
+          if (!isNullish(ctx)) ctx.moveTo(p.x, p.y);
           pp.start = pp.current;
           while (!pp.isCommandOrEnd()) {
             const p = pp.getAsCurrentPoint();
             pp.addMarker(p, pp.start);
             bb.addPoint(p.x, p.y);
-            if (ctx != null) ctx.lineTo(p.x, p.y);
+            if (!isNullish(ctx)) ctx.lineTo(p.x, p.y);
           }
           break;
         case 'L':
@@ -1421,7 +1430,7 @@ function build (opts) {
             const p = pp.getAsCurrentPoint();
             pp.addMarker(p, c);
             bb.addPoint(p.x, p.y);
-            if (ctx != null) ctx.lineTo(p.x, p.y);
+            if (!isNullish(ctx)) ctx.lineTo(p.x, p.y);
           }
           break;
         case 'H':
@@ -1431,7 +1440,7 @@ function build (opts) {
             pp.addMarker(newP, pp.current);
             pp.current = newP;
             bb.addPoint(pp.current.x, pp.current.y);
-            if (ctx != null) ctx.lineTo(pp.current.x, pp.current.y);
+            if (!isNullish(ctx)) ctx.lineTo(pp.current.x, pp.current.y);
           }
           break;
         case 'V':
@@ -1441,7 +1450,7 @@ function build (opts) {
             pp.addMarker(newP, pp.current);
             pp.current = newP;
             bb.addPoint(pp.current.x, pp.current.y);
-            if (ctx != null) ctx.lineTo(pp.current.x, pp.current.y);
+            if (!isNullish(ctx)) ctx.lineTo(pp.current.x, pp.current.y);
           }
           break;
         case 'C':
@@ -1453,7 +1462,7 @@ function build (opts) {
             const cp = pp.getAsCurrentPoint();
             pp.addMarker(cp, cntrl, p1);
             bb.addBezierCurve(curr.x, curr.y, p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
-            if (ctx != null) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
+            if (!isNullish(ctx)) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
           }
           break;
         case 'S':
@@ -1465,7 +1474,7 @@ function build (opts) {
             const cp = pp.getAsCurrentPoint();
             pp.addMarker(cp, cntrl, p1);
             bb.addBezierCurve(curr.x, curr.y, p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
-            if (ctx != null) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
+            if (!isNullish(ctx)) ctx.bezierCurveTo(p1.x, p1.y, cntrl.x, cntrl.y, cp.x, cp.y);
           }
           break;
         case 'Q':
@@ -1476,7 +1485,7 @@ function build (opts) {
             const cp = pp.getAsCurrentPoint();
             pp.addMarker(cp, cntrl, cntrl);
             bb.addQuadraticCurve(curr.x, curr.y, cntrl.x, cntrl.y, cp.x, cp.y);
-            if (ctx != null) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
+            if (!isNullish(ctx)) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
           }
           break;
         case 'T':
@@ -1488,7 +1497,7 @@ function build (opts) {
             const cp = pp.getAsCurrentPoint();
             pp.addMarker(cp, cntrl, cntrl);
             bb.addQuadraticCurve(curr.x, curr.y, cntrl.x, cntrl.y, cp.x, cp.y);
-            if (ctx != null) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
+            if (!isNullish(ctx)) ctx.quadraticCurveTo(cntrl.x, cntrl.y, cp.x, cp.y);
           }
           break;
         case 'A':
@@ -1560,7 +1569,7 @@ function build (opts) {
             pp.addMarkerAngle(cp, ah - dir * Math.PI);
 
             bb.addPoint(cp.x, cp.y); // TODO: this is too naive, make it better
-            if (ctx != null) {
+            if (!isNullish(ctx)) {
               const r = rx > ry ? rx : ry;
               const sx = rx > ry ? 1 : rx / ry;
               const sy = rx > ry ? ry / rx : 1;
@@ -1577,7 +1586,7 @@ function build (opts) {
           break;
         case 'Z':
         case 'z':
-          if (ctx != null) ctx.closePath();
+          if (!isNullish(ctx)) ctx.closePath();
           pp.current = pp.start;
         }
       }
@@ -1604,10 +1613,10 @@ function build (opts) {
 
       // render me using a temporary svg element
       const tempSvg = new svg.Element.svg();
-      tempSvg.attributes['viewBox'] = new svg.Property('viewBox', this.attribute('viewBox').value);
-      tempSvg.attributes['width'] = new svg.Property('width', width + 'px');
-      tempSvg.attributes['height'] = new svg.Property('height', height + 'px');
-      tempSvg.attributes['transform'] = new svg.Property('transform', this.attribute('patternTransform').value);
+      tempSvg.attributes.viewBox = new svg.Property('viewBox', this.attribute('viewBox').value);
+      tempSvg.attributes.width = new svg.Property('width', width + 'px');
+      tempSvg.attributes.height = new svg.Property('height', height + 'px');
+      tempSvg.attributes.transform = new svg.Property('transform', this.attribute('patternTransform').value);
       tempSvg.children = this.children;
 
       const c = document.createElement('canvas');
@@ -1641,13 +1650,13 @@ function build (opts) {
 
       // render me using a temporary svg element
       const tempSvg = new svg.Element.svg();
-      tempSvg.attributes['viewBox'] = new svg.Property('viewBox', this.attribute('viewBox').value);
-      tempSvg.attributes['refX'] = new svg.Property('refX', this.attribute('refX').value);
-      tempSvg.attributes['refY'] = new svg.Property('refY', this.attribute('refY').value);
-      tempSvg.attributes['width'] = new svg.Property('width', this.attribute('markerWidth').value);
-      tempSvg.attributes['height'] = new svg.Property('height', this.attribute('markerHeight').value);
-      tempSvg.attributes['fill'] = new svg.Property('fill', this.attribute('fill').valueOrDefault('black'));
-      tempSvg.attributes['stroke'] = new svg.Property('stroke', this.attribute('stroke').valueOrDefault('none'));
+      tempSvg.attributes.viewBox = new svg.Property('viewBox', this.attribute('viewBox').value);
+      tempSvg.attributes.refX = new svg.Property('refX', this.attribute('refX').value);
+      tempSvg.attributes.refY = new svg.Property('refY', this.attribute('refY').value);
+      tempSvg.attributes.width = new svg.Property('width', this.attribute('markerWidth').value);
+      tempSvg.attributes.height = new svg.Property('height', this.attribute('markerHeight').value);
+      tempSvg.attributes.fill = new svg.Property('fill', this.attribute('fill').valueOrDefault('black'));
+      tempSvg.attributes.stroke = new svg.Property('stroke', this.attribute('stroke').valueOrDefault('none'));
       tempSvg.children = this.children;
       tempSvg.render(ctx);
 
@@ -1698,7 +1707,7 @@ function build (opts) {
       };
 
       const g = this.getGradient(ctx, element);
-      if (g == null) return addParentOpacity(stopsContainer.stops[stopsContainer.stops.length - 1].color);
+      if (isNullish(g)) return addParentOpacity(stopsContainer.stops[stopsContainer.stops.length - 1].color);
       stopsContainer.stops.forEach(({offset, color}) => {
         g.addColorStop(offset, addParentOpacity(color));
       });
@@ -1708,20 +1717,20 @@ function build (opts) {
         const rootView = svg.ViewPort.viewPorts[0];
 
         const rect = new svg.Element.rect();
-        rect.attributes['x'] = new svg.Property('x', -svg.MAX_VIRTUAL_PIXELS / 3.0);
-        rect.attributes['y'] = new svg.Property('y', -svg.MAX_VIRTUAL_PIXELS / 3.0);
-        rect.attributes['width'] = new svg.Property('width', svg.MAX_VIRTUAL_PIXELS);
-        rect.attributes['height'] = new svg.Property('height', svg.MAX_VIRTUAL_PIXELS);
+        rect.attributes.x = new svg.Property('x', -svg.MAX_VIRTUAL_PIXELS / 3.0);
+        rect.attributes.y = new svg.Property('y', -svg.MAX_VIRTUAL_PIXELS / 3.0);
+        rect.attributes.width = new svg.Property('width', svg.MAX_VIRTUAL_PIXELS);
+        rect.attributes.height = new svg.Property('height', svg.MAX_VIRTUAL_PIXELS);
 
         const group = new svg.Element.g();
-        group.attributes['transform'] = new svg.Property('transform', this.attribute('gradientTransform').value);
+        group.attributes.transform = new svg.Property('transform', this.attribute('gradientTransform').value);
         group.children = [rect];
 
         const tempSvg = new svg.Element.svg();
-        tempSvg.attributes['x'] = new svg.Property('x', 0);
-        tempSvg.attributes['y'] = new svg.Property('y', 0);
-        tempSvg.attributes['width'] = new svg.Property('width', rootView.width);
-        tempSvg.attributes['height'] = new svg.Property('height', rootView.height);
+        tempSvg.attributes.x = new svg.Property('x', 0);
+        tempSvg.attributes.y = new svg.Property('y', 0);
+        tempSvg.attributes.width = new svg.Property('width', rootView.width);
+        tempSvg.attributes.height = new svg.Property('height', rootView.height);
         tempSvg.children = [group];
 
         const c = document.createElement('canvas');
@@ -1867,7 +1876,7 @@ function build (opts) {
 
     update (delta) {
       // set initial value
-      if (this.initialValue == null) {
+      if (isNullish(this.initialValue)) {
         this.initialValue = this.getProperty().value;
         this.initialUnits = this.getProperty().getUnits();
       }
@@ -1949,7 +1958,7 @@ function build (opts) {
         const r = from.r + (to.r - from.r) * p.progress;
         const g = from.g + (to.g - from.g) * p.progress;
         const b = from.b + (to.b - from.b) * p.progress;
-        return 'rgb(' + parseInt(r, 10) + ',' + parseInt(g, 10) + ',' + parseInt(b, 10) + ')';
+        return 'rgb(' + parseInt(r) + ',' + parseInt(g) + ',' + parseInt(b) + ')';
       }
       return this.attribute('from').value;
     }
@@ -2048,8 +2057,8 @@ function build (opts) {
       super.setContext(ctx);
 
       let textBaseline = this.style('dominant-baseline').toTextBaseline();
-      if (textBaseline == null) textBaseline = this.style('alignment-baseline').toTextBaseline();
-      if (textBaseline != null) ctx.textBaseline = textBaseline;
+      if (isNullish(textBaseline)) textBaseline = this.style('alignment-baseline').toTextBaseline();
+      if (!isNullish(textBaseline)) ctx.textBaseline = textBaseline;
     }
 
     getBoundingBox () {
@@ -2124,18 +2133,18 @@ function build (opts) {
         if (i > 0 && text[i - 1] !== ' ' && (i === text.length - 1 || text[i + 1] === ' ')) arabicForm = 'initial';
         if (typeof font.glyphs[c] !== 'undefined') {
           glyph = font.glyphs[c][arabicForm];
-          if (glyph == null && font.glyphs[c].type === 'glyph') glyph = font.glyphs[c];
+          if (isNullish(glyph) && font.glyphs[c].type === 'glyph') glyph = font.glyphs[c];
         }
       } else {
         glyph = font.glyphs[c];
       }
-      if (glyph == null) glyph = font.missingGlyph;
+      if (isNullish(glyph)) glyph = font.missingGlyph;
       return glyph;
     }
 
     renderChildren (ctx) {
       const customFont = this.parent.style('font-family').getDefinition();
-      if (customFont != null) {
+      if (!isNullish(customFont)) {
         const fontSize = this.parent.style('font-size').numValueOrDefault(svg.Font.Parse(svg.ctx.font).fontSize);
         const fontStyle = this.parent.style('font-style').valueOrDefault(svg.Font.Parse(svg.ctx.font).fontStyle);
         let text = this.getText();
@@ -2182,7 +2191,7 @@ function build (opts) {
 
     measureText (ctx) {
       const customFont = this.parent.style('font-family').getDefinition();
-      if (customFont != null) {
+      if (!isNullish(customFont)) {
         const fontSize = this.parent.style('font-size').numValueOrDefault(svg.Font.Parse(svg.ctx.font).fontSize);
         let measure = 0;
         let text = this.getText();
@@ -2225,7 +2234,8 @@ function build (opts) {
   svg.Element.tref = class extends svg.Element.TextElementBase {
     getText () {
       const element = this.getHrefAttribute().getDefinition();
-      if (element != null) return element.children[0].getText();
+      if (!isNullish(element)) return element.children[0].getText();
+      return undefined;
     }
   };
 
@@ -2290,13 +2300,12 @@ function build (opts) {
         if (svg.opts.useCORS === true) {
           this.img.crossOrigin = 'Anonymous';
         }
-        const self = this;
-        this.img.onload = function () {
-          self.loaded = true;
+        this.img.onload = () => {
+          this.loaded = true;
         };
-        this.img.onerror = function () {
+        this.img.onerror = () => {
           svg.log('ERROR: image "' + href + '" not found');
-          self.loaded = true;
+          this.loaded = true;
         };
         this.img.src = href;
       } else {
@@ -2387,14 +2396,14 @@ function build (opts) {
                 const prop = cssProp.indexOf(':');
                 const name = cssProp.substr(0, prop);
                 const value = cssProp.substr(prop + 1, cssProp.length - prop);
-                if (name != null && value != null) {
+                if (!isNullish(name) && !isNullish(value)) {
                   props[svg.trim(name)] = new svg.Property(svg.trim(name), svg.trim(value));
                 }
               });
               svg.Styles[cssClass] = props;
               if (cssClass === '@font-face') {
                 const fontFamily = props['font-family'].value.replace(/"/g, '');
-                const srcs = props['src'].value.split(',');
+                const srcs = props.src.value.split(',');
                 srcs.forEach((src) => {
                   if (src.includes('format("svg")')) {
                     const urlStart = src.indexOf('url');
@@ -2433,31 +2442,31 @@ function build (opts) {
 
     path (ctx) {
       const {_el: element} = this;
-      if (element != null) element.path(ctx);
+      if (!isNullish(element)) element.path(ctx);
     }
 
     getBoundingBox () {
       const {_el: element} = this;
-      if (element != null) return element.getBoundingBox();
+      if (!isNullish(element)) return element.getBoundingBox();
     }
 
     renderChildren (ctx) {
       const {_el: element} = this;
-      if (element != null) {
+      if (!isNullish(element)) {
         let tempSvg = element;
         if (element.type === 'symbol') {
           // render me using a temporary svg element in symbol cases (https://www.w3.org/TR/SVG/struct.html#UseElement)
           tempSvg = new svg.Element.svg();
           tempSvg.type = 'svg';
-          tempSvg.attributes['viewBox'] = new svg.Property('viewBox', element.attribute('viewBox').value);
-          tempSvg.attributes['preserveAspectRatio'] = new svg.Property('preserveAspectRatio', element.attribute('preserveAspectRatio').value);
-          tempSvg.attributes['overflow'] = new svg.Property('overflow', element.attribute('overflow').value);
+          tempSvg.attributes.viewBox = new svg.Property('viewBox', element.attribute('viewBox').value);
+          tempSvg.attributes.preserveAspectRatio = new svg.Property('preserveAspectRatio', element.attribute('preserveAspectRatio').value);
+          tempSvg.attributes.overflow = new svg.Property('overflow', element.attribute('overflow').value);
           tempSvg.children = element.children;
         }
         if (tempSvg.type === 'svg') {
           // if symbol or svg, inherit width/height from me
-          if (this.attribute('width').hasValue()) tempSvg.attributes['width'] = new svg.Property('width', this.attribute('width').value);
-          if (this.attribute('height').hasValue()) tempSvg.attributes['height'] = new svg.Property('height', this.attribute('height').value);
+          if (this.attribute('width').hasValue()) tempSvg.attributes.width = new svg.Property('width', this.attribute('width').value);
+          if (this.attribute('height').hasValue()) tempSvg.attributes.height = new svg.Property('height', this.attribute('height').value);
         }
         const oldParent = tempSvg.parent;
         tempSvg.parent = null;
@@ -2762,14 +2771,14 @@ function build (opts) {
     // bind mouse
     if (svg.opts.ignoreMouse !== true) {
       ctx.canvas.onclick = function (e) {
-        const args = e != null
+        const args = !isNullish(e)
           ? [e.clientX, e.clientY]
           : [event.clientX, event.clientY];
         const {x, y} = mapXY(new svg.Point(...args));
         svg.Mouse.onclick(x, y);
       };
       ctx.canvas.onmousemove = function (e) {
-        const args = e != null
+        const args = !isNullish(e)
           ? [e.clientX, e.clientY]
           : [event.clientX, event.clientY];
         const {x, y} = mapXY(new svg.Point(...args));
@@ -2812,17 +2821,17 @@ function build (opts) {
       }
       svg.ViewPort.SetCurrent(cWidth, cHeight);
 
-      if (svg.opts.offsetX != null) {
+      if (!isNullish(svg.opts.offsetX)) {
         e.attribute('x', true).value = svg.opts.offsetX;
       }
-      if (svg.opts.offsetY != null) {
+      if (!isNullish(svg.opts.offsetY)) {
         e.attribute('y', true).value = svg.opts.offsetY;
       }
-      if (svg.opts.scaleWidth != null || svg.opts.scaleHeight != null) {
+      if (!isNullish(svg.opts.scaleWidth) || !isNullish(svg.opts.scaleHeight)) {
         const viewBox = svg.ToNumberArray(e.attribute('viewBox').value);
         let xRatio = null, yRatio = null;
 
-        if (svg.opts.scaleWidth != null) {
+        if (!isNullish(svg.opts.scaleWidth)) {
           if (e.attribute('width').hasValue()) {
             xRatio = e.attribute('width').toPixels('x') / svg.opts.scaleWidth;
           } else if (!isNaN(viewBox[2])) {
@@ -2830,7 +2839,7 @@ function build (opts) {
           }
         }
 
-        if (svg.opts.scaleHeight != null) {
+        if (!isNullish(svg.opts.scaleHeight)) {
           if (e.attribute('height').hasValue()) {
             yRatio = e.attribute('height').toPixels('y') / svg.opts.scaleHeight;
           } else if (!isNaN(viewBox[3])) {
@@ -2838,8 +2847,8 @@ function build (opts) {
           }
         }
 
-        if (xRatio == null) { xRatio = yRatio; }
-        if (yRatio == null) { yRatio = xRatio; }
+        if (isNullish(xRatio)) { xRatio = yRatio; }
+        if (isNullish(yRatio)) { yRatio = xRatio; }
 
         e.attribute('width', true).value = svg.opts.scaleWidth;
         e.attribute('height', true).value = svg.opts.scaleHeight;
diff --git a/editor/canvg/rgbcolor.js b/editor/canvg/rgbcolor.js
index b3762975..aadcb1c5 100644
--- a/editor/canvg/rgbcolor.js
+++ b/editor/canvg/rgbcolor.js
@@ -158,9 +158,9 @@ const colorDefs = [
     example: ['rgb(123, 234, 45)', 'rgb(255,234,245)'],
     process (bits) {
       return [
-        parseInt(bits[1], 10),
-        parseInt(bits[2], 10),
-        parseInt(bits[3], 10)
+        parseInt(bits[1]),
+        parseInt(bits[2]),
+        parseInt(bits[3])
       ];
     }
   },
@@ -279,8 +279,7 @@ export default class RGBColor {
 margin: 3px;
 border: 1px solid black;
 background: ${listColor.toHex()};
-color: ${listColor.toHex()};`
-        ;
+color: ${listColor.toHex()};`;
         exampleDiv.append('test');
         const listItemValue = ` ${examples[i]} -> ${listColor.toRGB()} -> ${listColor.toHex()}`;
         listItem.append(exampleDiv, listItemValue);
diff --git a/editor/contextmenu.js b/editor/contextmenu.js
index f039a49a..e91232d9 100644
--- a/editor/contextmenu.js
+++ b/editor/contextmenu.js
@@ -93,9 +93,9 @@ const injectExtendedContextMenuItemIntoDom = function (menuItem) {
 * @returns {undefined}
 */
 export const injectExtendedContextMenuItemsIntoDom = function () {
-  for (const menuItem in contextMenuExtensions) {
-    injectExtendedContextMenuItemIntoDom(contextMenuExtensions[menuItem]);
-  }
+  Object.values(contextMenuExtensions).forEach((menuItem) => {
+    injectExtendedContextMenuItemIntoDom(menuItem);
+  });
 };
 /**
 * @function module:contextmenu.resetCustomMenus
diff --git a/editor/contextmenu/jQuery.contextMenu.js b/editor/contextmenu/jQuery.contextMenu.js
index 1715d3f0..9468115a 100755
--- a/editor/contextmenu/jQuery.contextMenu.js
+++ b/editor/contextmenu/jQuery.contextMenu.js
@@ -74,8 +74,7 @@ function jQueryContextMenu ($) {
         // Add contextMenu class
         menu.addClass('contextMenu');
         // Simulate a true right click
-        $(this).bind('mousedown', function (e) {
-          const evt = e;
+        $(this).bind('mousedown', function (evt) {
           $(this).mouseup(function (e) {
             const srcElement = $(this);
             srcElement.unbind('mouseup');
@@ -109,8 +108,8 @@ function jQueryContextMenu ($) {
               });
 
               // Keyboard
-              doc.keypress(function (e) {
-                switch (e.keyCode) {
+              doc.keypress(function (ev) {
+                switch (ev.keyCode) {
                 case 38: // up
                   if (!menu.find('LI.hover').length) {
                     menu.find('LI:last').addClass('hover');
@@ -143,7 +142,9 @@ function jQueryContextMenu ($) {
                 $('.contextMenu').hide();
                 // Callback
                 if (callback) {
-                  callback($(this).attr('href').substr(1), $(srcElement), {x: x - offset.left, y: y - offset.top, docX: x, docY: y});
+                  callback($(this).attr('href').substr(1), $(srcElement), {
+                    x: x - offset.left, y: y - offset.top, docX: x, docY: y
+                  });
                 }
                 return false;
               });
diff --git a/editor/coords.js b/editor/coords.js
index 1fbe6f02..19965d88 100644
--- a/editor/coords.js
+++ b/editor/coords.js
@@ -17,8 +17,10 @@ import {getTransformList} from './svgtransformlist.js';
 const $ = jQuery;
 
 // this is how we map paths to our preferred relative segment types
-const pathMap = [0, 'z', 'M', 'm', 'L', 'l', 'C', 'c', 'Q', 'q', 'A', 'a',
-  'H', 'h', 'V', 'v', 'S', 's', 'T', 't'];
+const pathMap = [
+  0, 'z', 'M', 'm', 'L', 'l', 'C', 'c', 'Q', 'q', 'A', 'a',
+  'H', 'h', 'V', 'v', 'S', 's', 'T', 't'
+];
 
 /**
  * @interface module:coords.EditorContext
@@ -59,9 +61,9 @@ export const remapElement = function (selected, changes, m) {
     doSnapping = editorContext_.getGridSnapping() && selected.parentNode.parentNode.localName === 'svg',
     finishUp = function () {
       if (doSnapping) {
-        for (const o in changes) {
-          changes[o] = snapToGrid(changes[o]);
-        }
+        Object.entries(changes).forEach(([o, value]) => {
+          changes[o] = snapToGrid(value);
+        });
       }
       assignAttributes(selected, changes, 1000, true);
     },
@@ -297,8 +299,8 @@ export const remapElement = function (selected, changes, m) {
         break;
       case 11: // relative elliptical arc (a)
       case 10: // absolute elliptical arc (A)
-        dstr += seg.r1 + ',' + seg.r2 + ' ' + seg.angle + ' ' + (+seg.largeArcFlag) +
-          ' ' + (+seg.sweepFlag) + ' ' + seg.x + ',' + seg.y + ' ';
+        dstr += seg.r1 + ',' + seg.r2 + ' ' + seg.angle + ' ' + Number(seg.largeArcFlag) +
+          ' ' + Number(seg.sweepFlag) + ' ' + seg.x + ',' + seg.y + ' ';
         break;
       case 17: // relative smooth cubic (s)
       case 16: // absolute smooth cubic (S)
diff --git a/editor/draw.js b/editor/draw.js
index 0e66edc6..bf2ceab3 100644
--- a/editor/draw.js
+++ b/editor/draw.js
@@ -139,7 +139,7 @@ export class Drawing {
     const n = this.svgElem_.getAttributeNS(NS.SE, 'nonce');
     // If already set in the DOM, use the nonce throughout the document
     // else, if randomizeIds(true) has been called, create and set the nonce.
-    if (!!n && randIds !== RandomizeModes.NEVER_RANDOMIZE) {
+    if (n && randIds !== RandomizeModes.NEVER_RANDOMIZE) {
       this.nonce_ = n;
     } else if (randIds === RandomizeModes.ALWAYS_RANDOMIZE) {
       this.setNonce(Math.floor(Math.random() * 100001));
@@ -253,7 +253,7 @@ export class Drawing {
       return false;
     }
     // extract the obj_num of this id
-    const num = parseInt(id.substr(front.length), 10);
+    const num = parseInt(id.substr(front.length));
 
     // if we didn't get a positive number or we already released this number
     // then return false.
@@ -669,8 +669,8 @@ export class Drawing {
    * @returns {Element}
    */
   copyElem (el) {
-    const self = this;
-    const getNextIdClosure = function () { return self.getNextId(); };
+    const that = this;
+    const getNextIdClosure = function () { return that.getNextId(); };
     return utilCopyElem(el, getNextIdClosure);
   }
 }
diff --git a/editor/embedapi.js b/editor/embedapi.js
index c8f2bc43..310a9cbd 100644
--- a/editor/embedapi.js
+++ b/editor/embedapi.js
@@ -22,11 +22,11 @@ let cbid = 0;
 */
 function getCallbackSetter (funcName) {
   return function (...args) {
-    const t = this, // New callback
-      cbid = t.send(funcName, args, function () {}); // The callback (currently it's nothing, but will be set later)
+    const that = this, // New callback
+      callbackID = this.send(funcName, args, function () { /* */ }); // The callback (currently it's nothing, but will be set later)
 
     return function (newCallback) {
-      t.callbacks[cbid] = newCallback; // Set callback
+      that.callbacks[callbackID] = newCallback; // Set callback
     };
   };
 }
@@ -39,14 +39,14 @@ function getCallbackSetter (funcName) {
 * @param {JSON} data
 * @returns {undefined}
 */
-function addCallback (t, {result, error, id: cbid}) {
-  if (typeof cbid === 'number' && t.callbacks[cbid]) {
+function addCallback (t, {result, error, id: callbackID}) {
+  if (typeof callbackID === 'number' && t.callbacks[callbackID]) {
     // These should be safe both because we check `cbid` is numeric and
     //   because the calls are from trusted origins
     if (result) {
-      t.callbacks[cbid](result); // lgtm [js/remote-property-injection]
+      t.callbacks[callbackID](result); // lgtm [js/remote-property-injection]
     } else {
-      t.callbacks[cbid](error, 'error'); // lgtm [js/remote-property-injection]
+      t.callbacks[callbackID](error, 'error'); // lgtm [js/remote-property-injection]
     }
   }
 }
@@ -67,7 +67,7 @@ function messageListener (e) {
     e.source !== this.frame.contentWindow ||
     (!allowedOrigins.includes('*') && !allowedOrigins.includes(e.origin))
   ) {
-    console.log(`The origin ${e.origin} was not whitelisted as an origin from which responses may be received by this ${window.origin} script.`);
+    console.log(`The origin ${e.origin} was not whitelisted as an origin from which responses may be received by this ${window.origin} script.`); // eslint-disable-line no-console
     return;
   }
   addCallback(this, data);
@@ -136,7 +136,7 @@ class EmbeddedSVGEdit {
   *   If supplied, it should probably be the same as svgEditor's allowedOrigins
   */
   constructor (frame, allowedOrigins) {
-    const t = this;
+    const that = this;
     this.allowedOrigins = allowedOrigins || [];
     // Initialize communication
     this.frame = frame;
@@ -326,7 +326,7 @@ class EmbeddedSVGEdit {
         const keyboardEvent = new KeyboardEvent(e.type, {
           key, keyCode, charCode, which
         });
-        t.frame.contentDocument.dispatchEvent(keyboardEvent);
+        that.frame.contentDocument.dispatchEvent(keyboardEvent);
       }
     });
   }
@@ -338,11 +338,11 @@ class EmbeddedSVGEdit {
   * @returns {Integer}
   */
   send (name, args, callback) {
-    const t = this;
+    const that = this;
     cbid++;
 
     this.callbacks[cbid] = callback;
-    setTimeout((function (cbid) {
+    setTimeout((function (callbackID) {
       return function () { // Delay for the callback to be set in case its synchronous
         /*
         * Todo: Handle non-JSON arguments and return values (undefined,
@@ -354,8 +354,8 @@ class EmbeddedSVGEdit {
         // We accept and post strings for the sake of IE9 support
         let sameOriginWithGlobal = false;
         try {
-          sameOriginWithGlobal = window.location.origin === t.frame.contentWindow.location.origin &&
-            t.frame.contentWindow.svgEditor.canvas;
+          sameOriginWithGlobal = window.location.origin === that.frame.contentWindow.location.origin &&
+            that.frame.contentWindow.svgEditor.canvas;
         } catch (err) {}
 
         if (sameOriginWithGlobal) {
@@ -365,17 +365,17 @@ class EmbeddedSVGEdit {
           //  of the current JSON-based communication API (e.g., not passing
           //  callbacks). We might be able to address these shortcomings; see
           //  the todo elsewhere in this file.
-          const message = {id: cbid},
-            {svgEditor: {canvas: svgCanvas}} = t.frame.contentWindow;
+          const message = {id: callbackID},
+            {svgEditor: {canvas: svgCanvas}} = that.frame.contentWindow;
           try {
-            message.result = svgCanvas[name].apply(svgCanvas, args);
+            message.result = svgCanvas[name](...args);
           } catch (err) {
             message.error = err.message;
           }
-          addCallback(t, message);
+          addCallback(that, message);
         } else { // Requires the ext-xdomain-messaging.js extension
-          t.frame.contentWindow.postMessage(JSON.stringify({
-            namespace: 'svgCanvas', id: cbid, name, args
+          that.frame.contentWindow.postMessage(JSON.stringify({
+            namespace: 'svgCanvas', id: callbackID, name, args
           }), '*');
         }
       };
diff --git a/editor/extensions/ext-connector.js b/editor/extensions/ext-connector.js
index 39de3fc2..f41152ae 100644
--- a/editor/extensions/ext-connector.js
+++ b/editor/extensions/ext-connector.js
@@ -67,7 +67,7 @@ export default {
     }
 
     function getOffset (side, line) {
-      const giveOffset = !!line.getAttribute('marker-' + side);
+      const giveOffset = line.getAttribute('marker-' + side);
       // const giveOffset = $(line).data(side+'_off');
 
       // TODO: Make this number (5) be based on marker width/height
@@ -170,7 +170,7 @@ export default {
         ['start', 'end'].forEach(function (pos, i) {
           const key = 'c_' + pos;
           let part = elData(this, key);
-          if (part == null) {
+          if (part === null || part === undefined) { // Does this ever return nullish values?
             part = document.getElementById(
               this.attributes['se:connector'].value.split(' ')[i]
             );
@@ -178,7 +178,7 @@ export default {
             elData(this, pos + '_bb', svgCanvas.getStrokedBBox([part]));
           } else part = document.getElementById(part);
           parts.push(part);
-        }.bind(this));
+        }, this);
 
         for (let i = 0; i < 2; i++) {
           const cElem = parts[i];
@@ -262,15 +262,15 @@ export default {
     (function () {
       const gse = svgCanvas.groupSelectedElements;
 
-      svgCanvas.groupSelectedElements = function () {
+      svgCanvas.groupSelectedElements = function (...args) {
         svgCanvas.removeFromSelection($(connSel).toArray());
-        return gse.apply(this, arguments);
+        return gse.apply(this, args);
       };
 
       const mse = svgCanvas.moveSelectedElements;
 
-      svgCanvas.moveSelectedElements = function () {
-        const cmd = mse.apply(this, arguments);
+      svgCanvas.moveSelectedElements = function (...args) {
+        const cmd = mse.apply(this, args);
         updateConnectors();
         return cmd;
       };
@@ -331,7 +331,7 @@ export default {
       buttons: strings.buttons.map((button, i) => {
         return Object.assign(buttons[i], button);
       }),
-      async addLangData ({lang, importLocale}) {
+      /* async */ addLangData ({lang, importLocale}) {
         return {
           data: strings.langList
         };
@@ -548,8 +548,8 @@ export default {
           const end = elem.getAttribute('marker-end');
           curLine = elem;
           $(elem)
-            .data('start_off', !!start)
-            .data('end_off', !!end);
+            .data('start_off', Boolean(start))
+            .data('end_off', Boolean(end));
 
           if (elem.tagName === 'line' && mid) {
             // Convert to polyline to accept mid-arrow
diff --git a/editor/extensions/ext-overview_window.js b/editor/extensions/ext-overview_window.js
index 13a50e13..e90617f4 100644
--- a/editor/extensions/ext-overview_window.js
+++ b/editor/extensions/ext-overview_window.js
@@ -16,7 +16,7 @@ export default {
     // https://code.google.com/p/chromium/issues/detail?id=565120.
     if (isChrome()) {
       const verIndex = navigator.userAgent.indexOf('Chrome/') + 7;
-      const chromeVersion = parseInt(navigator.userAgent.substring(verIndex), 10);
+      const chromeVersion = parseInt(navigator.userAgent.substring(verIndex));
       if (chromeVersion < 49) {
         return;
       }
diff --git a/editor/extensions/ext-webappfind.js b/editor/extensions/ext-webappfind.js
index 21288afc..e478caec 100644
--- a/editor/extensions/ext-webappfind.js
+++ b/editor/extensions/ext-webappfind.js
@@ -24,7 +24,7 @@ export default {
       * @throws {Error} Unexpected event type
       * @returns {undefined}
       */
-      (win, {data, origin}) => {
+      (win, {data, origin}) => { // eslint-disable-line no-shadow
         // console.log('data, origin', data, origin);
         let type, content;
         try {
@@ -78,17 +78,18 @@ export default {
           if (!pathID) { // Not ready yet as haven't received first payload
             return;
           }
-          window.postMessage({
-            webappfind: {
-              type: saveMessage,
-              pathID,
-              content: svgEditor.canvas.getSvgString()
-            }
-          }, window.location.origin === 'null'
-            // Avoid "null" string error for `file:` protocol (even
-            //  though file protocol not currently supported by add-on)
-            ? '*'
-            : window.location.origin
+          window.postMessage(
+            {
+              webappfind: {
+                type: saveMessage,
+                pathID,
+                content: svgEditor.canvas.getSvgString()
+              }
+            }, window.location.origin === 'null'
+              // Avoid "null" string error for `file:` protocol (even
+              //  though file protocol not currently supported by add-on)
+              ? '*'
+              : window.location.origin
           );
         }
       }
diff --git a/editor/extensions/imagelib/openclipart.js b/editor/extensions/imagelib/openclipart.js
index 45de98aa..6772d0e6 100644
--- a/editor/extensions/imagelib/openclipart.js
+++ b/editor/extensions/imagelib/openclipart.js
@@ -1,12 +1,21 @@
 import {jml, body, nbsp} from '../../external/jamilih/jml-es.js';
-
 import $ from '../../external/query-result/esm/index.js';
 import {manipulation} from '../../external/qr-manipulation/dist/index-es.js';
+
 manipulation($, jml);
 
 const baseAPIURL = 'https://openclipart.org/search/json/';
 
+/**
+ * Shows results after query submission.
+ * @param {string} url
+ * @returns {undefined}
+ */
 async function processResults (url) {
+  /**
+   * @param {string} query
+   * @returns {external:JamilihArray}
+   */
   function queryLink (query) {
     return ['a', {
       href: 'javascript: void(0);',
@@ -22,7 +31,7 @@ async function processResults (url) {
 
   const r = await fetch(url);
   const json = await r.json();
-  console.log('json', json);
+  // console.log('json', json);
 
   if (!json || json.msg !== 'success') {
     alert('There was a problem downloading the results');
@@ -74,7 +83,7 @@ async function processResults (url) {
           async click (e) {
             e.preventDefault();
             const {value: svgURL, id} = this.dataset;
-            console.log('this', id, svgURL);
+            // console.log('this', id, svgURL);
             const post = (message) => {
               // Todo: Make origin customizable as set by opening window
               // Todo: If dropping IE9, avoid stringifying
@@ -90,7 +99,7 @@ async function processResults (url) {
             });
             const result = await fetch(svgURL);
             const svg = await result.text();
-            console.log('h', svgURL, svg);
+            // console.log('url and svg', svgURL, svg);
             post({
               href: svgURL,
               data: svg
diff --git a/editor/external/dynamic-import-polyfill/importModule.js b/editor/external/dynamic-import-polyfill/importModule.js
index ed9a4826..5f6545a3 100644
--- a/editor/external/dynamic-import-polyfill/importModule.js
+++ b/editor/external/dynamic-import-polyfill/importModule.js
@@ -5,12 +5,23 @@
  * @module importModule
  */
 
+/**
+ * Converts a possible relative URL into an absolute one.
+ * @param {string} url
+ * @returns {string}
+ */
 function toAbsoluteURL (url) {
   const a = document.createElement('a');
   a.setAttribute('href', url); // <a href="hoge.html">
   return a.cloneNode(false).href; // -> "http://example.com/hoge.html"
 }
 
+/**
+ * Add any of the whitelisted attributes to the script tag.
+ * @param {HTMLScriptElement} script
+ * @param {PlainObject.<string, string>} atts
+ * @returns {undefined}
+ */
 function addScriptAtts (script, atts) {
   ['id', 'class', 'type'].forEach((prop) => {
     if (prop in atts) {
@@ -27,18 +38,19 @@ function addScriptAtts (script, atts) {
 */
 /**
 * @function module:importModule.importSetGlobalDefault
-* @param {string} url
+* @param {string|string[]} url
 * @param {module:importModule.ImportConfig} config
-* @returns {*} The return depends on the export of the targeted module.
+* @returns {Promise} The value to which it resolves depends on the export of the targeted module.
 */
-export async function importSetGlobalDefault (url, config) {
+export function importSetGlobalDefault (url, config) {
   return importSetGlobal(url, {...config, returnDefault: true});
 }
 /**
 * @function module:importModule.importSetGlobal
-* @param {string} url
+* @param {string|string[]} url
 * @param {module:importModule.ImportConfig} config
-* @returns {ArbitraryModule|*} The return depends on the export of the targeted module.
+* @returns {Promise} The promise resolves to either an `ArbitraryModule` or
+*   any other value depends on the export of the targeted module.
 */
 export async function importSetGlobal (url, {global, returnDefault}) {
   // Todo: Replace calls to this function with `import()` when supported
@@ -51,14 +63,21 @@ export async function importSetGlobal (url, {global, returnDefault}) {
   await importScript(url);
   return window[global];
 }
-// Addition by Brett
+/**
+ *
+ * @author Brett Zamir (other items are from `dynamic-import-polyfill`)
+ * @param {string|string[]} url
+ * @param {Object} [atts={}]
+ * @returns {Promise} Resolves to `undefined` or rejects with an `Error` upon a
+ *   script loading error
+ */
 export function importScript (url, atts = {}) {
   if (Array.isArray(url)) {
     return Promise.all(url.map((u) => {
       return importScript(u, atts);
     }));
   }
-  return new Promise((resolve, reject) => {
+  return new Promise((resolve, reject) => { // eslint-disable-line promise/avoid-new
     const script = document.createElement('script');
     const destructor = () => {
       script.onerror = null;
@@ -82,13 +101,22 @@ export function importScript (url, atts = {}) {
   });
 }
 
+/**
+ *
+ * @param {string|string[]} url
+ * @param {Object} [atts={}]
+ * @param {PlainObject} opts
+ * @param {boolean} [opts.returnDefault=false} = {}]
+ * @returns {Promise} Resolves to value of loading module or rejects with
+ *   `Error` upon a script loading error.
+ */
 export function importModule (url, atts = {}, {returnDefault = false} = {}) {
   if (Array.isArray(url)) {
     return Promise.all(url.map((u) => {
       return importModule(u, atts);
     }));
   }
-  return new Promise((resolve, reject) => {
+  return new Promise((resolve, reject) => { // eslint-disable-line promise/avoid-new
     const vector = '$importModule$' + Math.random().toString(32).slice(2);
     const script = document.createElement('script');
     const destructor = () => {
diff --git a/editor/history.js b/editor/history.js
index fa40ce49..c53fb227 100644
--- a/editor/history.js
+++ b/editor/history.js
@@ -5,7 +5,7 @@
  * @copyright 2010 Jeff Schiller
  */
 
-import {getHref, setHref, getRotationAngle} from './utilities.js';
+import {getHref, setHref, getRotationAngle, isNullish} from './utilities.js';
 import {removeElementFromListMap} from './svgtransformlist.js';
 
 /**
@@ -285,9 +285,9 @@ export class RemoveElementCommand extends Command {
     }
 
     removeElementFromListMap(this.elem);
-    if (this.nextSibling == null) {
+    if (isNullish(this.nextSibling)) {
       if (window.console) {
-        console.log('Error: reference element was lost');
+        console.log('Error: reference element was lost'); // eslint-disable-line no-console
       }
     }
     this.parent.insertBefore(this.elem, this.nextSibling); // Don't use `before` or `prepend` as `this.nextSibling` may be `null`
@@ -670,7 +670,7 @@ export class UndoManager {
     const oldValues = new Array(i), elements = new Array(i);
     while (i--) {
       const elem = elems[i];
-      if (elem == null) { continue; }
+      if (isNullish(elem)) { continue; }
       elements[i] = elem;
       oldValues[i] = elem.getAttribute(attrName);
     }
@@ -695,7 +695,7 @@ export class UndoManager {
     let i = changeset.elements.length;
     while (i--) {
       const elem = changeset.elements[i];
-      if (elem == null) { continue; }
+      if (isNullish(elem)) { continue; }
       const changes = {};
       changes[attrName] = changeset.oldValues[i];
       if (changes[attrName] !== elem.getAttribute(attrName)) {
diff --git a/editor/historyrecording.js b/editor/historyrecording.js
index e7e40feb..49437dde 100644
--- a/editor/historyrecording.js
+++ b/editor/historyrecording.js
@@ -77,8 +77,8 @@ class HistoryRecordingService {
     if (this.currentBatchCommand_) {
       const batchCommand = this.currentBatchCommand_;
       this.batchCommandStack_.pop();
-      const {length} = this.batchCommandStack_;
-      this.currentBatchCommand_ = length ? this.batchCommandStack_[length - 1] : null;
+      const {length: len} = this.batchCommandStack_;
+      this.currentBatchCommand_ = len ? this.batchCommandStack_[len - 1] : null;
       this.addCommand_(batchCommand);
     }
     return this;
@@ -141,7 +141,7 @@ class HistoryRecordingService {
    * Private function to add a command to the history or current batch command.
    * @private
    * @param {Command} cmd
-   * @returns {module:history.HistoryRecordingService}
+   * @returns {module:history.HistoryRecordingService|undefined}
    */
   addCommand_ (cmd) {
     if (!this.undoManager_) { return this; }
@@ -150,6 +150,7 @@ class HistoryRecordingService {
     } else {
       this.undoManager_.addCommandToHistory(cmd);
     }
+    return undefined;
   }
 }
 /**
diff --git a/editor/jQuery.attr.js b/editor/jQuery.attr.js
index cf6e132e..5dc2f302 100644
--- a/editor/jQuery.attr.js
+++ b/editor/jQuery.attr.js
@@ -18,7 +18,7 @@
 * @param {external:jQuery} $ The jQuery object to which to add the plug-in
 * @returns {external:jQuery}
 */
-export default function ($) {
+export default function jQueryPluginSVG ($) {
   const proxied = $.fn.attr,
     svgns = 'http://www.w3.org/2000/svg';
   /**
@@ -32,7 +32,7 @@ export default function ($) {
   */
   $.fn.attr = function (key, value) {
     const len = this.length;
-    if (!len) { return proxied.apply(this, arguments); }
+    if (!len) { return proxied.call(this, key, value); }
     for (let i = 0; i < len; ++i) {
       const elem = this[i];
       // set/get SVG attribute
@@ -70,7 +70,7 @@ export default function ($) {
           return attr;
         }
       } else {
-        return proxied.apply(this, arguments);
+        return proxied.call(this, key, value);
       }
     }
     return this;
diff --git a/editor/jgraduate/jQuery.jGraduate.js b/editor/jgraduate/jQuery.jGraduate.js
index 47ab1289..fa576aac 100644
--- a/editor/jgraduate/jQuery.jGraduate.js
+++ b/editor/jgraduate/jQuery.jGraduate.js
@@ -407,7 +407,8 @@ export default function ($) {
         '<div class="jGraduate_OkCancel">' +
           '<input type="button" id="' + id + '_jGraduate_Ok" class="jGraduate_Ok" value="OK"/>' +
           '<input type="button" id="' + id + '_jGraduate_Cancel" class="jGraduate_Cancel" value="Cancel"/>' +
-        '</div>');
+        '</div>'
+      );
 
       // --------------
       // Set up all the SVG elements (the gradient, stops and rectangle)
@@ -1234,7 +1235,7 @@ export default function ($) {
             const sm = spreadMethodOpt.val();
             curGradient.setAttribute('spreadMethod', sm);
           }
-          showFocus = type === 'rg' && curGradient.getAttribute('fx') != null && !(cx === fx && cy === fy);
+          showFocus = type === 'rg' && curGradient.getAttribute('fx') !== null && !(cx === fx && cy === fy);
           $('#' + id + '_jGraduate_focusCoord').toggle(showFocus);
           if (showFocus) {
             $('#' + id + '_jGraduate_match_ctr')[0].checked = false;
diff --git a/editor/jgraduate/jQuery.jPicker.js b/editor/jgraduate/jQuery.jPicker.js
index 2377391b..527b4378 100755
--- a/editor/jgraduate/jQuery.jPicker.js
+++ b/editor/jgraduate/jQuery.jPicker.js
@@ -29,6 +29,15 @@ function toFixedNumeric (value, precision) {
   return Math.round(value * Math.pow(10, precision)) / Math.pow(10, precision);
 }
 
+/**
+ * Whether a value is `null` or `undefined`.
+ * @param {Any} val
+ * @returns {boolean}
+ */
+const isNullish = (val) => {
+  return val === null || val === undefined;
+};
+
 /**
 * @function module:jPicker.jPicker
 * @param {external:jQuery} $ The jQuery object to wrap (with {@link external:jQuery.loadingStylesheets}, {@link external:jQuery.fn.$.fn.jPicker}, {@link external:jQuery.fn.$.fn.jPicker.defaults})
@@ -67,36 +76,54 @@ const jPicker = function ($) {
   */
   class Slider {
     constructor (bar, options) {
-      const $this = this;
+      const that = this;
+      /**
+       * Fire events on the supplied `context`
+       * @param {module:jPicker.JPickerInit} context
+       * @returns {undefined}
+       */
       function fireChangeEvents (context) {
-        for (let i = 0; i < changeEvents.length; i++) {
-          changeEvents[i].call($this, $this, context);
-        }
+        changeEvents.forEach((changeEvent) => {
+          changeEvent.call(that, that, context);
+        });
       }
-      // bind the mousedown to the bar not the arrow for quick snapping to the clicked location
+
+      /**
+       * Bind the mousedown to the bar not the arrow for quick snapping to the clicked location.
+       * @param {external:jQuery.Event} e
+       * @returns {undefined}
+       */
       function mouseDown (e) {
         const off = bar.offset();
-        offset = {l: off.left | 0, t: off.top | 0};
+        offset = {l: off.left | 0, t: off.top | 0}; // eslint-disable-line no-bitwise
         clearTimeout(timeout);
         // using setTimeout for visual updates - once the style is updated the browser will re-render internally allowing the next Javascript to run
         timeout = setTimeout(function () {
-          setValuesFromMousePosition.call($this, e);
+          setValuesFromMousePosition.call(that, e);
         }, 0);
         // Bind mousemove and mouseup event to the document so it responds when dragged of of the bar - we will unbind these when on mouseup to save processing
         $(document).bind('mousemove', mouseMove).bind('mouseup', mouseUp);
         e.preventDefault(); // don't try to select anything or drag the image to the desktop
       }
-      // set the values as the mouse moves
+      /**
+       * Set the values as the mouse moves.
+       * @param {external:jQuery.Event} e
+       * @returns {false}
+       */
       function mouseMove (e) {
         clearTimeout(timeout);
         timeout = setTimeout(function () {
-          setValuesFromMousePosition.call($this, e);
+          setValuesFromMousePosition.call(that, e);
         }, 0);
         e.stopPropagation();
         e.preventDefault();
         return false;
       }
-      // unbind the document events - they aren't needed when not dragging
+      /**
+       * Unbind the document events - they aren't needed when not dragging.
+       * @param {external:jQuery.Event} e
+       * @returns {false}
+       */
       function mouseUp (e) {
         $(document).unbind('mouseup', mouseUp).unbind('mousemove', mouseMove);
         e.stopPropagation();
@@ -114,7 +141,7 @@ const jPicker = function ($) {
         else if (locX > barW) locX = barW;
         if (locY < 0) locY = 0;
         else if (locY > barH) locY = barH;
-        val.call($this, 'xy', {x: ((locX / barW) * rangeX) + minX, y: ((locY / barH) * rangeY) + minY});
+        val.call(that, 'xy', {x: ((locX / barW) * rangeX) + minX, y: ((locY / barH) * rangeY) + minY});
       }
       function draw () {
         const
@@ -125,6 +152,7 @@ const jPicker = function ($) {
         let arrowOffsetX = 0,
           arrowOffsetY = 0;
         setTimeout(function () {
+          /* eslint-disable no-bitwise */
           if (rangeX > 0) { // range is greater than zero
             // constrain to bounds
             if (x === maxX) arrowOffsetX = barW;
@@ -143,12 +171,13 @@ const jPicker = function ($) {
           else arrowOffsetY -= arrowH >> 1;
           // set the arrow position based on these offsets
           arrow.css({left: arrowOffsetX + 'px', top: arrowOffsetY + 'px'});
-        }, 0);
+          /* eslint no-bitwise: ["error"] */
+        });
       }
       function val (name, value, context) {
         const set = value !== undefined;
         if (!set) {
-          if (name === undefined || name == null) name = 'xy';
+          if (isNullish(name)) name = 'xy';
           switch (name.toLowerCase()) {
           case 'x': return x;
           case 'y': return y;
@@ -156,11 +185,11 @@ const jPicker = function ($) {
           default: return {x, y};
           }
         }
-        if (context != null && context === $this) return;
+        if (!isNullish(context) && context === that) return;
         let changed = false;
 
         let newX, newY;
-        if (name == null) name = 'xy';
+        if (isNullish(name)) name = 'xy';
         switch (name.toLowerCase()) {
         case 'x':
           newX = (value && ((value.x && value.x | 0) || value | 0)) || 0;
@@ -174,7 +203,7 @@ const jPicker = function ($) {
           newY = (value && value.y && value.y | 0) || 0;
           break;
         }
-        if (newX != null) {
+        if (!isNullish(newX)) {
           if (newX < minX) newX = minX;
           else if (newX > maxX) newX = maxX;
           if (x !== newX) {
@@ -182,7 +211,7 @@ const jPicker = function ($) {
             changed = true;
           }
         }
-        if (newY != null) {
+        if (!isNullish(newY)) {
           if (newY < minY) newY = minY;
           else if (newY > maxY) newY = maxY;
           if (y !== newY) {
@@ -190,12 +219,12 @@ const jPicker = function ($) {
             changed = true;
           }
         }
-        changed && fireChangeEvents.call($this, context || $this);
+        changed && fireChangeEvents.call(that, context || that);
       }
       function range (name, value) {
         const set = value !== undefined;
         if (!set) {
-          if (name === undefined || name == null) name = 'all';
+          if (isNullish(name)) name = 'all';
           switch (name.toLowerCase()) {
           case 'minx': return minX;
           case 'maxx': return maxX;
@@ -212,7 +241,8 @@ const jPicker = function ($) {
           newMaxX,
           newMinY,
           newMaxY;
-        if (name == null) name = 'all';
+        if (isNullish(name)) name = 'all';
+        /* eslint-disable no-bitwise */
         switch (name.toLowerCase()) {
         case 'minx':
           newMinX = (value && ((value.minX && value.minX | 0) || value | 0)) || 0;
@@ -242,19 +272,21 @@ const jPicker = function ($) {
           newMaxY = (value && value.maxY && value.maxY | 0) || 0;
           break;
         }
-        if (newMinX != null && minX !== newMinX) {
+
+        /* eslint no-bitwise: ["error"] */
+        if (!isNullish(newMinX) && minX !== newMinX) {
           minX = newMinX;
           rangeX = maxX - minX;
         }
-        if (newMaxX != null && maxX !== newMaxX) {
+        if (!isNullish(newMaxX) && maxX !== newMaxX) {
           maxX = newMaxX;
           rangeX = maxX - minX;
         }
-        if (newMinY != null && minY !== newMinY) {
+        if (!isNullish(newMinY) && minY !== newMinY) {
           minY = newMinY;
           rangeY = maxY - minY;
         }
-        if (newMaxY != null && maxY !== newMaxY) {
+        if (!isNullish(newMaxY) && maxY !== newMaxY) {
           maxY = newMaxY;
           rangeY = maxY - minY;
         }
@@ -288,7 +320,11 @@ const jPicker = function ($) {
         arrow = bar.find('img:first'), // the arrow image to drag
         changeEvents = [];
 
-      $.extend(true, $this, // public properties, methods, and event bindings - these we need to access from other controls
+      $.extend(
+        true,
+        // public properties, methods, and event bindings - these we need
+        //   to access from other controls
+        that,
         {
           val,
           range,
@@ -305,26 +341,26 @@ const jPicker = function ($) {
       bar.h = (options.map && options.map.height) || bar.height();
       // bind mousedown event
       bar.bind('mousedown', mouseDown);
-      bind.call($this, draw);
+      bind.call(that, draw);
     }
   }
   // controls for all the input elements for the typing in color values
   function ColorValuePicker (picker, color, bindedHex, alphaPrecision) {
-    const $this = this; // private properties and methods
+    const that = this; // private properties and methods
     const inputs = picker.find('td.Text input');
     // input box key down - use arrows to alter color
     function keyDown (e) {
-      if (e.target.value === '' && e.target !== hex.get(0) && ((bindedHex != null && e.target !== bindedHex.get(0)) || bindedHex == null)) return;
+      if (e.target.value === '' && e.target !== hex.get(0) && ((!isNullish(bindedHex) && e.target !== bindedHex.get(0)) || isNullish(bindedHex))) return;
       if (!validateKey(e)) return e;
       switch (e.target) {
       case red.get(0):
         switch (e.keyCode) {
         case 38:
-          red.val(setValueInRange.call($this, (red.val() << 0) + 1, 0, 255));
+          red.val(setValueInRange.call(that, (red.val() << 0) + 1, 0, 255));
           color.val('r', red.val(), e.target);
           return false;
         case 40:
-          red.val(setValueInRange.call($this, (red.val() << 0) - 1, 0, 255));
+          red.val(setValueInRange.call(that, (red.val() << 0) - 1, 0, 255));
           color.val('r', red.val(), e.target);
           return false;
         }
@@ -332,11 +368,11 @@ const jPicker = function ($) {
       case green.get(0):
         switch (e.keyCode) {
         case 38:
-          green.val(setValueInRange.call($this, (green.val() << 0) + 1, 0, 255));
+          green.val(setValueInRange.call(that, (green.val() << 0) + 1, 0, 255));
           color.val('g', green.val(), e.target);
           return false;
         case 40:
-          green.val(setValueInRange.call($this, (green.val() << 0) - 1, 0, 255));
+          green.val(setValueInRange.call(that, (green.val() << 0) - 1, 0, 255));
           color.val('g', green.val(), e.target);
           return false;
         }
@@ -344,11 +380,11 @@ const jPicker = function ($) {
       case blue.get(0):
         switch (e.keyCode) {
         case 38:
-          blue.val(setValueInRange.call($this, (blue.val() << 0) + 1, 0, 255));
+          blue.val(setValueInRange.call(that, (blue.val() << 0) + 1, 0, 255));
           color.val('b', blue.val(), e.target);
           return false;
         case 40:
-          blue.val(setValueInRange.call($this, (blue.val() << 0) - 1, 0, 255));
+          blue.val(setValueInRange.call(that, (blue.val() << 0) - 1, 0, 255));
           color.val('b', blue.val(), e.target);
           return false;
         }
@@ -356,11 +392,11 @@ const jPicker = function ($) {
       case alpha && alpha.get(0):
         switch (e.keyCode) {
         case 38:
-          alpha.val(setValueInRange.call($this, parseFloat(alpha.val()) + 1, 0, 100));
+          alpha.val(setValueInRange.call(that, parseFloat(alpha.val()) + 1, 0, 100));
           color.val('a', toFixedNumeric((alpha.val() * 255) / 100, alphaPrecision), e.target);
           return false;
         case 40:
-          alpha.val(setValueInRange.call($this, parseFloat(alpha.val()) - 1, 0, 100));
+          alpha.val(setValueInRange.call(that, parseFloat(alpha.val()) - 1, 0, 100));
           color.val('a', toFixedNumeric((alpha.val() * 255) / 100, alphaPrecision), e.target);
           return false;
         }
@@ -368,11 +404,11 @@ const jPicker = function ($) {
       case hue.get(0):
         switch (e.keyCode) {
         case 38:
-          hue.val(setValueInRange.call($this, (hue.val() << 0) + 1, 0, 360));
+          hue.val(setValueInRange.call(that, (hue.val() << 0) + 1, 0, 360));
           color.val('h', hue.val(), e.target);
           return false;
         case 40:
-          hue.val(setValueInRange.call($this, (hue.val() << 0) - 1, 0, 360));
+          hue.val(setValueInRange.call(that, (hue.val() << 0) - 1, 0, 360));
           color.val('h', hue.val(), e.target);
           return false;
         }
@@ -380,11 +416,11 @@ const jPicker = function ($) {
       case saturation.get(0):
         switch (e.keyCode) {
         case 38:
-          saturation.val(setValueInRange.call($this, (saturation.val() << 0) + 1, 0, 100));
+          saturation.val(setValueInRange.call(that, (saturation.val() << 0) + 1, 0, 100));
           color.val('s', saturation.val(), e.target);
           return false;
         case 40:
-          saturation.val(setValueInRange.call($this, (saturation.val() << 0) - 1, 0, 100));
+          saturation.val(setValueInRange.call(that, (saturation.val() << 0) - 1, 0, 100));
           color.val('s', saturation.val(), e.target);
           return false;
         }
@@ -392,11 +428,11 @@ const jPicker = function ($) {
       case value.get(0):
         switch (e.keyCode) {
         case 38:
-          value.val(setValueInRange.call($this, (value.val() << 0) + 1, 0, 100));
+          value.val(setValueInRange.call(that, (value.val() << 0) + 1, 0, 100));
           color.val('v', value.val(), e.target);
           return false;
         case 40:
-          value.val(setValueInRange.call($this, (value.val() << 0) - 1, 0, 100));
+          value.val(setValueInRange.call(that, (value.val() << 0) - 1, 0, 100));
           color.val('v', value.val(), e.target);
           return false;
         }
@@ -406,36 +442,36 @@ const jPicker = function ($) {
     // input box key up - validate value and set color
     function keyUp (e) {
       if (e.target.value === '' && e.target !== hex.get(0) &&
-        ((bindedHex != null && e.target !== bindedHex.get(0)) ||
-        bindedHex == null)) return;
+        ((!isNullish(bindedHex) && e.target !== bindedHex.get(0)) ||
+        isNullish(bindedHex))) return;
       if (!validateKey(e)) return e;
       switch (e.target) {
       case red.get(0):
-        red.val(setValueInRange.call($this, red.val(), 0, 255));
+        red.val(setValueInRange.call(that, red.val(), 0, 255));
         color.val('r', red.val(), e.target);
         break;
       case green.get(0):
-        green.val(setValueInRange.call($this, green.val(), 0, 255));
+        green.val(setValueInRange.call(that, green.val(), 0, 255));
         color.val('g', green.val(), e.target);
         break;
       case blue.get(0):
-        blue.val(setValueInRange.call($this, blue.val(), 0, 255));
+        blue.val(setValueInRange.call(that, blue.val(), 0, 255));
         color.val('b', blue.val(), e.target);
         break;
       case alpha && alpha.get(0):
-        alpha.val(setValueInRange.call($this, alpha.val(), 0, 100));
+        alpha.val(setValueInRange.call(that, alpha.val(), 0, 100));
         color.val('a', toFixedNumeric((alpha.val() * 255) / 100, alphaPrecision), e.target);
         break;
       case hue.get(0):
-        hue.val(setValueInRange.call($this, hue.val(), 0, 360));
+        hue.val(setValueInRange.call(that, hue.val(), 0, 360));
         color.val('h', hue.val(), e.target);
         break;
       case saturation.get(0):
-        saturation.val(setValueInRange.call($this, saturation.val(), 0, 100));
+        saturation.val(setValueInRange.call(that, saturation.val(), 0, 100));
         color.val('s', saturation.val(), e.target);
         break;
       case value.get(0):
-        value.val(setValueInRange.call($this, value.val(), 0, 100));
+        value.val(setValueInRange.call(that, value.val(), 0, 100));
         color.val('v', value.val(), e.target);
         break;
       case hex.get(0):
@@ -450,13 +486,13 @@ const jPicker = function ($) {
         break;
       case ahex && ahex.get(0):
         ahex.val(ahex.val().replace(/[^a-fA-F0-9]/g, '').toLowerCase().substring(0, 2));
-        color.val('a', ahex.val() != null ? parseInt(ahex.val(), 16) : null, e.target);
+        color.val('a', !isNullish(ahex.val()) ? parseInt(ahex.val(), 16) : null, e.target);
         break;
       }
     }
     // input box blur - reset to original if value empty
     function blur (e) {
-      if (color.val() != null) {
+      if (!isNullish(color.val())) {
         switch (e.target) {
         case red.get(0): red.val(color.val('r')); break;
         case green.get(0): green.val(color.val('g')); break;
@@ -497,16 +533,16 @@ const jPicker = function ($) {
     }
     function colorChanged (ui, context) {
       const all = ui.val('all');
-      if (context !== red.get(0)) red.val(all != null ? all.r : '');
-      if (context !== green.get(0)) green.val(all != null ? all.g : '');
-      if (context !== blue.get(0)) blue.val(all != null ? all.b : '');
-      if (alpha && context !== alpha.get(0)) alpha.val(all != null ? toFixedNumeric((all.a * 100) / 255, alphaPrecision) : '');
-      if (context !== hue.get(0)) hue.val(all != null ? all.h : '');
-      if (context !== saturation.get(0)) saturation.val(all != null ? all.s : '');
-      if (context !== value.get(0)) value.val(all != null ? all.v : '');
-      if (context !== hex.get(0) && ((bindedHex && context !== bindedHex.get(0)) || !bindedHex)) hex.val(all != null ? all.hex : '');
-      if (bindedHex && context !== bindedHex.get(0) && context !== hex.get(0)) bindedHex.val(all != null ? all.hex : '');
-      if (ahex && context !== ahex.get(0)) ahex.val(all != null ? all.ahex.substring(6) : '');
+      if (context !== red.get(0)) red.val(!isNullish(all) ? all.r : '');
+      if (context !== green.get(0)) green.val(!isNullish(all) ? all.g : '');
+      if (context !== blue.get(0)) blue.val(!isNullish(all) ? all.b : '');
+      if (alpha && context !== alpha.get(0)) alpha.val(!isNullish(all) ? toFixedNumeric((all.a * 100) / 255, alphaPrecision) : '');
+      if (context !== hue.get(0)) hue.val(!isNullish(all) ? all.h : '');
+      if (context !== saturation.get(0)) saturation.val(!isNullish(all) ? all.s : '');
+      if (context !== value.get(0)) value.val(!isNullish(all) ? all.v : '');
+      if (context !== hex.get(0) && ((bindedHex && context !== bindedHex.get(0)) || !bindedHex)) hex.val(!isNullish(all) ? all.hex : '');
+      if (bindedHex && context !== bindedHex.get(0) && context !== hex.get(0)) bindedHex.val(!isNullish(all) ? all.hex : '');
+      if (ahex && context !== ahex.get(0)) ahex.val(!isNullish(all) ? all.ahex.substring(6) : '');
     }
     function destroy () {
       // unbind all events and null objects
@@ -533,7 +569,7 @@ const jPicker = function ($) {
       value = inputs.eq(2),
       hex = inputs.eq(inputs.length > 7 ? 7 : 6),
       ahex = inputs.length > 7 ? inputs.eq(8) : null;
-    $.extend(true, $this, {
+    $.extend(true, that, {
       // public properties and methods
       destroy
     });
@@ -544,15 +580,15 @@ const jPicker = function ($) {
 
   /**
   * @typedef {PlainObject} module:jPicker.JPickerInit
-  * @property {Integer} a
-  * @property {Integer} b
-  * @property {Integer} g
-  * @property {Integer} h
-  * @property {Integer} r
-  * @property {Integer} s
-  * @property {Integer} v
-  * @property {string} hex
-  * @property {string} ahex
+  * @property {Integer} [a]
+  * @property {Integer} [b]
+  * @property {Integer} [g]
+  * @property {Integer} [h]
+  * @property {Integer} [r]
+  * @property {Integer} [s]
+  * @property {Integer} [v]
+  * @property {string} [hex]
+  * @property {string} [ahex]
   */
 
   /**
@@ -577,21 +613,21 @@ const jPicker = function ($) {
     * @param {module:jPicker.JPickerInit} init
     */
     Color: function (init) {
-      const $this = this;
+      const that = this;
       function fireChangeEvents (context) {
-        for (let i = 0; i < changeEvents.length; i++) changeEvents[i].call($this, $this, context);
+        for (let i = 0; i < changeEvents.length; i++) changeEvents[i].call(that, that, context);
       }
       function val (name, value, context) {
         // Kind of ugly
         const set = Boolean(value);
         if (set && value.ahex === '') value.ahex = '00000000';
         if (!set) {
-          if (name === undefined || name == null || name === '') name = 'all';
-          if (r == null) return null;
+          if (isNullish(name) || name === '') name = 'all';
+          if (isNullish(r)) return null;
           switch (name.toLowerCase()) {
           case 'ahex': return ColorMethods.rgbaToHex({r, g, b, a});
           case 'hex': return val('ahex').substring(0, 6);
-          case 'all': return {r, g, b, a, h, s, v, hex: val.call($this, 'hex'), ahex: val.call($this, 'ahex')};
+          case 'all': return {r, g, b, a, h, s, v, hex: val.call(that, 'hex'), ahex: val.call(that, 'ahex')};
           default:
             let ret = {};
             const nameLength = name.length;
@@ -628,55 +664,55 @@ const jPicker = function ($) {
               }
             }
             return typeof ret === 'object' && !Object.keys(ret).length
-              ? val.call($this, 'all')
+              ? val.call(that, 'all')
               : ret;
           }
         }
-        if (context != null && context === $this) return;
-        if (name == null) name = '';
+        if (!isNullish(context) && context === that) return;
+        if (isNullish(name)) name = '';
 
         let changed = false;
-        if (value == null) {
-          if (r != null) {
+        if (isNullish(value)) {
+          if (!isNullish(r)) {
             r = null;
             changed = true;
           }
-          if (g != null) {
+          if (!isNullish(g)) {
             g = null;
             changed = true;
           }
-          if (b != null) {
+          if (!isNullish(b)) {
             b = null;
             changed = true;
           }
-          if (a != null) {
+          if (!isNullish(a)) {
             a = null;
             changed = true;
           }
-          if (h != null) {
+          if (!isNullish(h)) {
             h = null;
             changed = true;
           }
-          if (s != null) {
+          if (!isNullish(s)) {
             s = null;
             changed = true;
           }
-          if (v != null) {
+          if (!isNullish(v)) {
             v = null;
             changed = true;
           }
-          changed && fireChangeEvents.call($this, context || $this);
+          changed && fireChangeEvents.call(that, context || that);
           return;
         }
         switch (name.toLowerCase()) {
         case 'ahex':
-        case 'hex':
+        case 'hex': {
           const ret = ColorMethods.hexToRgba((value && (value.ahex || value.hex)) || value || 'none');
-          val.call($this, 'rgba', {r: ret.r, g: ret.g, b: ret.b, a: name === 'ahex' ? ret.a : a != null ? a : 255}, context);
+          val.call(that, 'rgba', {r: ret.r, g: ret.g, b: ret.b, a: name === 'ahex' ? ret.a : !isNullish(a) ? a : 255}, context);
           break;
-        default:
-          if (value && (value.ahex != null || value.hex != null)) {
-            val.call($this, 'ahex', value.ahex || value.hex || '00000000', context);
+        } default: {
+          if (value && (!isNullish(value.ahex) || !isNullish(value.hex))) {
+            val.call(that, 'ahex', value.ahex || value.hex || '00000000', context);
             return;
           }
           const newV = {};
@@ -724,7 +760,7 @@ const jPicker = function ($) {
               }
               break;
             case 'a':
-              newV.a = value && value.a != null ? value.a | 0 : value | 0;
+              newV.a = value && !isNullish(value.a) ? value.a | 0 : value | 0;
               if (newV.a < 0) newV.a = 0;
               else if (newV.a > 255) newV.a = 255;
               if (a !== newV.a) {
@@ -746,7 +782,7 @@ const jPicker = function ($) {
             case 's':
               if (rgb) continue;
               hsv = true;
-              newV.s = value.s != null ? value.s | 0 : value | 0;
+              newV.s = !isNullish(value.s) ? value.s | 0 : value | 0;
               if (newV.s < 0) newV.s = 0;
               else if (newV.s > 100) newV.s = 100;
               if (s !== newV.s) {
@@ -757,7 +793,7 @@ const jPicker = function ($) {
             case 'v':
               if (rgb) continue;
               hsv = true;
-              newV.v = value.v != null ? value.v | 0 : value | 0;
+              newV.v = !isNullish(value.v) ? value.v | 0 : value | 0;
               if (newV.v < 0) newV.v = 0;
               else if (newV.v > 100) newV.v = 100;
               if (v !== newV.v) {
@@ -776,16 +812,17 @@ const jPicker = function ($) {
               ({h, s, v} = ret);
             } else if (hsv) {
               h = h || 0;
-              s = s != null ? s : 100;
-              v = v != null ? v : 100;
+              s = !isNullish(s) ? s : 100;
+              v = !isNullish(v) ? v : 100;
               const ret = ColorMethods.hsvToRgb({h, s, v});
               ({r, g, b} = ret);
             }
-            a = a != null ? a : 255;
-            fireChangeEvents.call($this, context || $this);
+            a = !isNullish(a) ? a : 255;
+            fireChangeEvents.call(that, context || that);
           }
           break;
         }
+        }
       }
       function bind (callback) {
         if (typeof callback === 'function') changeEvents.push(callback);
@@ -802,7 +839,7 @@ const jPicker = function ($) {
       }
       let r, g, b, a, h, s, v, changeEvents = [];
 
-      $.extend(true, $this, {
+      $.extend(true, that, {
         // public properties and methods
         val,
         bind,
@@ -810,19 +847,19 @@ const jPicker = function ($) {
         destroy
       });
       if (init) {
-        if (init.ahex != null) {
+        if (!isNullish(init.ahex)) {
           val('ahex', init);
-        } else if (init.hex != null) {
+        } else if (!isNullish(init.hex)) {
           val(
-            (init.a != null ? 'a' : '') + 'hex',
-            init.a != null
+            (!isNullish(init.a) ? 'a' : '') + 'hex',
+            !isNullish(init.a)
               ? {ahex: init.hex + ColorMethods.intToHex(init.a)}
               : init
           );
-        } else if (init.r != null && init.g != null && init.b != null) {
-          val('rgb' + (init.a != null ? 'a' : ''), init);
-        } else if (init.h != null && init.s != null && init.v != null) {
-          val('hsv' + (init.a != null ? 'a' : ''), init);
+        } else if (!isNullish(init.r) && !isNullish(init.g) && !isNullish(init.b)) {
+          val('rgb' + (!isNullish(init.a) ? 'a' : ''), init);
+        } else if (!isNullish(init.h) && !isNullish(init.s) && !isNullish(init.v)) {
+          val('hsv' + (!isNullish(init.a) ? 'a' : ''), init);
         }
       }
     },
@@ -958,8 +995,8 @@ const jPicker = function ($) {
         } else {
           if (h === 360) h = 0;
           h /= 60;
-          s = s / 100;
-          v = v / 100;
+          s /= 100;
+          v /= 100;
           const i = h | 0,
             f = h - i,
             p = v * (1 - s),
@@ -1017,30 +1054,33 @@ const jPicker = function ($) {
   * @namespace
   * @memberof external:jQuery.fn
   * @param {external:jQuery.fn.jPickerOptions} options
+  * @param {function} [commitCallback]
+  * @param {function} [liveCallback]
+  * @param {function} [cancelCallback]
   * @returns {external:jQuery}
   */
-  $.fn.jPicker = function (options) {
-    const $arguments = arguments;
+  $.fn.jPicker = function (options, commitCallback, liveCallback, cancelCallback) {
     return this.each(function () {
-      const $this = this, settings = $.extend(true, {}, $.fn.jPicker.defaults, options); // local copies for YUI compressor
-      if ($($this).get(0).nodeName.toLowerCase() === 'input') { // Add color picker icon if binding to an input element and bind the events to the input
+      const that = this,
+        settings = $.extend(true, {}, $.fn.jPicker.defaults, options); // local copies for YUI compressor
+      if ($(that).get(0).nodeName.toLowerCase() === 'input') { // Add color picker icon if binding to an input element and bind the events to the input
         $.extend(true, settings, {
           window: {
             bindToInput: true,
             expandable: true,
-            input: $($this)
+            input: $(that)
           }
         });
-        if ($($this).val() === '') {
+        if ($(that).val() === '') {
           settings.color.active = new Color({hex: null});
           settings.color.current = new Color({hex: null});
-        } else if (ColorMethods.validateHex($($this).val())) {
-          settings.color.active = new Color({hex: $($this).val(), a: settings.color.active.val('a')});
-          settings.color.current = new Color({hex: $($this).val(), a: settings.color.active.val('a')});
+        } else if (ColorMethods.validateHex($(that).val())) {
+          settings.color.active = new Color({hex: $(that).val(), a: settings.color.active.val('a')});
+          settings.color.current = new Color({hex: $(that).val(), a: settings.color.active.val('a')});
         }
       }
       if (settings.window.expandable) {
-        $($this).after('<span class="jPicker"><span class="Icon"><span class="Color">&nbsp;</span><span class="Alpha">&nbsp;</span><span class="Image" title="Click To Open Color Picker">&nbsp;</span><span class="Container">&nbsp;</span></span></span>');
+        $(that).after('<span class="jPicker"><span class="Icon"><span class="Color">&nbsp;</span><span class="Alpha">&nbsp;</span><span class="Image" title="Click To Open Color Picker">&nbsp;</span><span class="Container">&nbsp;</span></span></span>');
       } else {
         settings.window.liveUpdate = false; // Basic control binding for inline use - You will need to override the liveCallback or commitCallback function to retrieve results
       }
@@ -1061,60 +1101,60 @@ const jPicker = function ($) {
         switch (colorMode) {
         case 'h':
           setTimeout(function () {
-            setBG.call($this, colorMapDiv, 'transparent');
-            setImgLoc.call($this, colorMapL1, 0);
-            setAlpha.call($this, colorMapL1, 100);
-            setImgLoc.call($this, colorMapL2, 260);
-            setAlpha.call($this, colorMapL2, 100);
-            setBG.call($this, colorBarDiv, 'transparent');
-            setImgLoc.call($this, colorBarL1, 0);
-            setAlpha.call($this, colorBarL1, 100);
-            setImgLoc.call($this, colorBarL2, 260);
-            setAlpha.call($this, colorBarL2, 100);
-            setImgLoc.call($this, colorBarL3, 260);
-            setAlpha.call($this, colorBarL3, 100);
-            setImgLoc.call($this, colorBarL4, 260);
-            setAlpha.call($this, colorBarL4, 100);
-            setImgLoc.call($this, colorBarL6, 260);
-            setAlpha.call($this, colorBarL6, 100);
+            setBG.call(that, colorMapDiv, 'transparent');
+            setImgLoc.call(that, colorMapL1, 0);
+            setAlpha.call(that, colorMapL1, 100);
+            setImgLoc.call(that, colorMapL2, 260);
+            setAlpha.call(that, colorMapL2, 100);
+            setBG.call(that, colorBarDiv, 'transparent');
+            setImgLoc.call(that, colorBarL1, 0);
+            setAlpha.call(that, colorBarL1, 100);
+            setImgLoc.call(that, colorBarL2, 260);
+            setAlpha.call(that, colorBarL2, 100);
+            setImgLoc.call(that, colorBarL3, 260);
+            setAlpha.call(that, colorBarL3, 100);
+            setImgLoc.call(that, colorBarL4, 260);
+            setAlpha.call(that, colorBarL4, 100);
+            setImgLoc.call(that, colorBarL6, 260);
+            setAlpha.call(that, colorBarL6, 100);
           }, 0);
           colorMap.range('all', {minX: 0, maxX: 100, minY: 0, maxY: 100});
           colorBar.range('rangeY', {minY: 0, maxY: 360});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('s'), y: 100 - active.val('v')}, colorMap);
           colorBar.val('y', 360 - active.val('h'), colorBar);
           break;
         case 's':
           setTimeout(function () {
-            setBG.call($this, colorMapDiv, 'transparent');
-            setImgLoc.call($this, colorMapL1, -260);
-            setImgLoc.call($this, colorMapL2, -520);
-            setImgLoc.call($this, colorBarL1, -260);
-            setImgLoc.call($this, colorBarL2, -520);
-            setImgLoc.call($this, colorBarL6, 260);
-            setAlpha.call($this, colorBarL6, 100);
+            setBG.call(that, colorMapDiv, 'transparent');
+            setImgLoc.call(that, colorMapL1, -260);
+            setImgLoc.call(that, colorMapL2, -520);
+            setImgLoc.call(that, colorBarL1, -260);
+            setImgLoc.call(that, colorBarL2, -520);
+            setImgLoc.call(that, colorBarL6, 260);
+            setAlpha.call(that, colorBarL6, 100);
           }, 0);
           colorMap.range('all', {minX: 0, maxX: 360, minY: 0, maxY: 100});
           colorBar.range('rangeY', {minY: 0, maxY: 100});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('h'), y: 100 - active.val('v')}, colorMap);
           colorBar.val('y', 100 - active.val('s'), colorBar);
           break;
         case 'v':
           setTimeout(function () {
-            setBG.call($this, colorMapDiv, '000000');
-            setImgLoc.call($this, colorMapL1, -780);
-            setImgLoc.call($this, colorMapL2, 260);
-            setBG.call($this, colorBarDiv, hex);
-            setImgLoc.call($this, colorBarL1, -520);
-            setImgLoc.call($this, colorBarL2, 260);
-            setAlpha.call($this, colorBarL2, 100);
-            setImgLoc.call($this, colorBarL6, 260);
-            setAlpha.call($this, colorBarL6, 100);
+            setBG.call(that, colorMapDiv, '000000');
+            setImgLoc.call(that, colorMapL1, -780);
+            setImgLoc.call(that, colorMapL2, 260);
+            setBG.call(that, colorBarDiv, hex);
+            setImgLoc.call(that, colorBarL1, -520);
+            setImgLoc.call(that, colorBarL2, 260);
+            setAlpha.call(that, colorBarL2, 100);
+            setImgLoc.call(that, colorBarL6, 260);
+            setAlpha.call(that, colorBarL6, 100);
           }, 0);
           colorMap.range('all', {minX: 0, maxX: 360, minY: 0, maxY: 100});
           colorBar.range('rangeY', {minY: 0, maxY: 100});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('h'), y: 100 - active.val('s')}, colorMap);
           colorBar.val('y', 100 - active.val('v'), colorBar);
           break;
@@ -1123,7 +1163,7 @@ const jPicker = function ($) {
           rgbBar = -780;
           colorMap.range('all', {minX: 0, maxX: 255, minY: 0, maxY: 255});
           colorBar.range('rangeY', {minY: 0, maxY: 255});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('b'), y: 255 - active.val('g')}, colorMap);
           colorBar.val('y', 255 - active.val('r'), colorBar);
           break;
@@ -1132,7 +1172,7 @@ const jPicker = function ($) {
           rgbBar = -1820;
           colorMap.range('all', {minX: 0, maxX: 255, minY: 0, maxY: 255});
           colorBar.range('rangeY', {minY: 0, maxY: 255});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('b'), y: 255 - active.val('r')}, colorMap);
           colorBar.val('y', 255 - active.val('g'), colorBar);
           break;
@@ -1141,24 +1181,24 @@ const jPicker = function ($) {
           rgbBar = -2860;
           colorMap.range('all', {minX: 0, maxX: 255, minY: 0, maxY: 255});
           colorBar.range('rangeY', {minY: 0, maxY: 255});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('r'), y: 255 - active.val('g')}, colorMap);
           colorBar.val('y', 255 - active.val('b'), colorBar);
           break;
         case 'a':
           setTimeout(function () {
-            setBG.call($this, colorMapDiv, 'transparent');
-            setImgLoc.call($this, colorMapL1, -260);
-            setImgLoc.call($this, colorMapL2, -520);
-            setImgLoc.call($this, colorBarL1, 260);
-            setImgLoc.call($this, colorBarL2, 260);
-            setAlpha.call($this, colorBarL2, 100);
-            setImgLoc.call($this, colorBarL6, 0);
-            setAlpha.call($this, colorBarL6, 100);
+            setBG.call(that, colorMapDiv, 'transparent');
+            setImgLoc.call(that, colorMapL1, -260);
+            setImgLoc.call(that, colorMapL2, -520);
+            setImgLoc.call(that, colorBarL1, 260);
+            setImgLoc.call(that, colorBarL2, 260);
+            setAlpha.call(that, colorBarL2, 100);
+            setImgLoc.call(that, colorBarL6, 0);
+            setAlpha.call(that, colorBarL6, 100);
           }, 0);
           colorMap.range('all', {minX: 0, maxX: 360, minY: 0, maxY: 100});
           colorBar.range('rangeY', {minY: 0, maxY: 255});
-          if (active.val('ahex') == null) break;
+          if (isNullish(active.val('ahex'))) break;
           colorMap.val('xy', {x: active.val('h'), y: 100 - active.val('v')}, colorMap);
           colorBar.val('y', 255 - active.val('a'), colorBar);
           break;
@@ -1172,49 +1212,49 @@ const jPicker = function ($) {
         case 'v':
         case 'a':
           setTimeout(function () {
-            setAlpha.call($this, colorMapL1, 100);
-            setAlpha.call($this, colorBarL1, 100);
-            setImgLoc.call($this, colorBarL3, 260);
-            setAlpha.call($this, colorBarL3, 100);
-            setImgLoc.call($this, colorBarL4, 260);
-            setAlpha.call($this, colorBarL4, 100);
+            setAlpha.call(that, colorMapL1, 100);
+            setAlpha.call(that, colorBarL1, 100);
+            setImgLoc.call(that, colorBarL3, 260);
+            setAlpha.call(that, colorBarL3, 100);
+            setImgLoc.call(that, colorBarL4, 260);
+            setAlpha.call(that, colorBarL4, 100);
           }, 0);
           break;
         case 'r':
         case 'g':
         case 'b':
           setTimeout(function () {
-            setBG.call($this, colorMapDiv, 'transparent');
-            setBG.call($this, colorBarDiv, 'transparent');
-            setAlpha.call($this, colorBarL1, 100);
-            setAlpha.call($this, colorMapL1, 100);
-            setImgLoc.call($this, colorMapL1, rgbMap);
-            setImgLoc.call($this, colorMapL2, rgbMap - 260);
-            setImgLoc.call($this, colorBarL1, rgbBar - 780);
-            setImgLoc.call($this, colorBarL2, rgbBar - 520);
-            setImgLoc.call($this, colorBarL3, rgbBar);
-            setImgLoc.call($this, colorBarL4, rgbBar - 260);
-            setImgLoc.call($this, colorBarL6, 260);
-            setAlpha.call($this, colorBarL6, 100);
+            setBG.call(that, colorMapDiv, 'transparent');
+            setBG.call(that, colorBarDiv, 'transparent');
+            setAlpha.call(that, colorBarL1, 100);
+            setAlpha.call(that, colorMapL1, 100);
+            setImgLoc.call(that, colorMapL1, rgbMap);
+            setImgLoc.call(that, colorMapL2, rgbMap - 260);
+            setImgLoc.call(that, colorBarL1, rgbBar - 780);
+            setImgLoc.call(that, colorBarL2, rgbBar - 520);
+            setImgLoc.call(that, colorBarL3, rgbBar);
+            setImgLoc.call(that, colorBarL4, rgbBar - 260);
+            setImgLoc.call(that, colorBarL6, 260);
+            setAlpha.call(that, colorBarL6, 100);
           }, 0);
           break;
         }
-        if (active.val('ahex') == null) return;
-        activeColorChanged.call($this, active);
+        if (isNullish(active.val('ahex'))) return;
+        activeColorChanged.call(that, active);
       }
       // Update color when user changes text values
       function activeColorChanged (ui, context) {
-        if (context == null || (context !== colorBar && context !== colorMap)) positionMapAndBarArrows.call($this, ui, context);
+        if (isNullish(context) || (context !== colorBar && context !== colorMap)) positionMapAndBarArrows.call(that, ui, context);
         setTimeout(function () {
-          updatePreview.call($this, ui);
-          updateMapVisuals.call($this, ui);
-          updateBarVisuals.call($this, ui);
+          updatePreview.call(that, ui);
+          updateMapVisuals.call(that, ui);
+          updateBarVisuals.call(that, ui);
         }, 0);
       }
       // user has dragged the ColorMap pointer
       function mapValueChanged (ui, context) {
         const {active} = color;
-        if (context !== colorMap && active.val() == null) return;
+        if (context !== colorMap && isNullish(active.val())) return;
         const xy = ui.val('all');
         switch (settings.color.mode) {
         case 'h':
@@ -1241,7 +1281,7 @@ const jPicker = function ($) {
       // user has dragged the ColorBar slider
       function colorBarValueChanged (ui, context) {
         const {active} = color;
-        if (context !== colorBar && active.val() == null) return;
+        if (context !== colorBar && isNullish(active.val())) return;
         switch (settings.color.mode) {
         case 'h':
           active.val('h', {h: 360 - ui.val('y')}, context);
@@ -1270,47 +1310,50 @@ const jPicker = function ($) {
       function positionMapAndBarArrows (ui, context) {
         if (context !== colorMap) {
           switch (settings.color.mode) {
-          case 'h':
+          case 'h': {
             const sv = ui.val('sv');
-            colorMap.val('xy', {x: sv != null ? sv.s : 100, y: 100 - (sv != null ? sv.v : 100)}, context);
+            colorMap.val('xy', {x: !isNullish(sv) ? sv.s : 100, y: 100 - (!isNullish(sv) ? sv.v : 100)}, context);
             break;
-          case 's':
-          case 'a':
+          } case 's': { // eslint-disable-line no-empty
+          }
+          // Fall through
+          case 'a': {
             const hv = ui.val('hv');
-            colorMap.val('xy', {x: (hv && hv.h) || 0, y: 100 - (hv != null ? hv.v : 100)}, context);
+            colorMap.val('xy', {x: (hv && hv.h) || 0, y: 100 - (!isNullish(hv) ? hv.v : 100)}, context);
             break;
-          case 'v':
+          } case 'v': {
             const hs = ui.val('hs');
-            colorMap.val('xy', {x: (hs && hs.h) || 0, y: 100 - (hs != null ? hs.s : 100)}, context);
+            colorMap.val('xy', {x: (hs && hs.h) || 0, y: 100 - (!isNullish(hs) ? hs.s : 100)}, context);
             break;
-          case 'r':
+          } case 'r': {
             const bg = ui.val('bg');
             colorMap.val('xy', {x: (bg && bg.b) || 0, y: 255 - ((bg && bg.g) || 0)}, context);
             break;
-          case 'g':
+          } case 'g': {
             const br = ui.val('br');
             colorMap.val('xy', {x: (br && br.b) || 0, y: 255 - ((br && br.r) || 0)}, context);
             break;
-          case 'b':
+          } case 'b': {
             const rg = ui.val('rg');
             colorMap.val('xy', {x: (rg && rg.r) || 0, y: 255 - ((rg && rg.g) || 0)}, context);
             break;
           }
+          }
         }
         if (context !== colorBar) {
           switch (settings.color.mode) {
           case 'h':
             colorBar.val('y', 360 - (ui.val('h') || 0), context);
             break;
-          case 's':
+          case 's': {
             const s = ui.val('s');
-            colorBar.val('y', 100 - (s != null ? s : 100), context);
+            colorBar.val('y', 100 - (!isNullish(s) ? s : 100), context);
             break;
-          case 'v':
+          } case 'v': {
             const v = ui.val('v');
-            colorBar.val('y', 100 - (v != null ? v : 100), context);
+            colorBar.val('y', 100 - (!isNullish(v) ? v : 100), context);
             break;
-          case 'r':
+          } case 'r':
             colorBar.val('y', 255 - (ui.val('r') || 0), context);
             break;
           case 'g':
@@ -1319,69 +1362,70 @@ const jPicker = function ($) {
           case 'b':
             colorBar.val('y', 255 - (ui.val('b') || 0), context);
             break;
-          case 'a':
+          case 'a': {
             const a = ui.val('a');
-            colorBar.val('y', 255 - (a != null ? a : 255), context);
+            colorBar.val('y', 255 - (!isNullish(a) ? a : 255), context);
             break;
           }
+          }
         }
       }
       function updatePreview (ui) {
         try {
           const all = ui.val('all');
           activePreview.css({backgroundColor: (all && '#' + all.hex) || 'transparent'});
-          setAlpha.call($this, activePreview, (all && toFixedNumeric((all.a * 100) / 255, 4)) || 0);
+          setAlpha.call(that, activePreview, (all && toFixedNumeric((all.a * 100) / 255, 4)) || 0);
         } catch (e) { }
       }
       function updateMapVisuals (ui) {
         switch (settings.color.mode) {
         case 'h':
-          setBG.call($this, colorMapDiv, new Color({h: ui.val('h') || 0, s: 100, v: 100}).val('hex'));
+          setBG.call(that, colorMapDiv, new Color({h: ui.val('h') || 0, s: 100, v: 100}).val('hex'));
           break;
         case 's':
-        case 'a':
+        case 'a': {
           const s = ui.val('s');
-          setAlpha.call($this, colorMapL2, 100 - (s != null ? s : 100));
+          setAlpha.call(that, colorMapL2, 100 - (!isNullish(s) ? s : 100));
           break;
-        case 'v':
+        } case 'v': {
           const v = ui.val('v');
-          setAlpha.call($this, colorMapL1, v != null ? v : 100);
+          setAlpha.call(that, colorMapL1, !isNullish(v) ? v : 100);
           break;
-        case 'r':
-          setAlpha.call($this, colorMapL2, toFixedNumeric((ui.val('r') || 0) / 255 * 100, 4));
+        } case 'r':
+          setAlpha.call(that, colorMapL2, toFixedNumeric((ui.val('r') || 0) / 255 * 100, 4));
           break;
         case 'g':
-          setAlpha.call($this, colorMapL2, toFixedNumeric((ui.val('g') || 0) / 255 * 100, 4));
+          setAlpha.call(that, colorMapL2, toFixedNumeric((ui.val('g') || 0) / 255 * 100, 4));
           break;
         case 'b':
-          setAlpha.call($this, colorMapL2, toFixedNumeric((ui.val('b') || 0) / 255 * 100));
+          setAlpha.call(that, colorMapL2, toFixedNumeric((ui.val('b') || 0) / 255 * 100));
           break;
         }
         const a = ui.val('a');
-        setAlpha.call($this, colorMapL3, toFixedNumeric(((255 - (a || 0)) * 100) / 255, 4));
+        setAlpha.call(that, colorMapL3, toFixedNumeric(((255 - (a || 0)) * 100) / 255, 4));
       }
       function updateBarVisuals (ui) {
         switch (settings.color.mode) {
-        case 'h':
+        case 'h': {
           const a = ui.val('a');
-          setAlpha.call($this, colorBarL5, toFixedNumeric(((255 - (a || 0)) * 100) / 255, 4));
+          setAlpha.call(that, colorBarL5, toFixedNumeric(((255 - (a || 0)) * 100) / 255, 4));
           break;
-        case 's':
+        } case 's': {
           const hva = ui.val('hva'),
-            saturatedColor = new Color({h: (hva && hva.h) || 0, s: 100, v: hva != null ? hva.v : 100});
-          setBG.call($this, colorBarDiv, saturatedColor.val('hex'));
-          setAlpha.call($this, colorBarL2, 100 - (hva != null ? hva.v : 100));
-          setAlpha.call($this, colorBarL5, toFixedNumeric(((255 - ((hva && hva.a) || 0)) * 100) / 255, 4));
+            saturatedColor = new Color({h: (hva && hva.h) || 0, s: 100, v: !isNullish(hva) ? hva.v : 100});
+          setBG.call(that, colorBarDiv, saturatedColor.val('hex'));
+          setAlpha.call(that, colorBarL2, 100 - (!isNullish(hva) ? hva.v : 100));
+          setAlpha.call(that, colorBarL5, toFixedNumeric(((255 - ((hva && hva.a) || 0)) * 100) / 255, 4));
           break;
-        case 'v':
+        } case 'v': {
           const hsa = ui.val('hsa'),
-            valueColor = new Color({h: (hsa && hsa.h) || 0, s: hsa != null ? hsa.s : 100, v: 100});
-          setBG.call($this, colorBarDiv, valueColor.val('hex'));
-          setAlpha.call($this, colorBarL5, toFixedNumeric(((255 - ((hsa && hsa.a) || 0)) * 100) / 255, 4));
+            valueColor = new Color({h: (hsa && hsa.h) || 0, s: !isNullish(hsa) ? hsa.s : 100, v: 100});
+          setBG.call(that, colorBarDiv, valueColor.val('hex'));
+          setAlpha.call(that, colorBarL5, toFixedNumeric(((255 - ((hsa && hsa.a) || 0)) * 100) / 255, 4));
           break;
-        case 'r':
+        } case 'r':
         case 'g':
-        case 'b':
+        case 'b': {
           const rgba = ui.val('rgba');
           let hValue = 0, vValue = 0;
           if (settings.color.mode === 'r') {
@@ -1395,16 +1439,16 @@ const jPicker = function ($) {
             vValue = (rgba && rgba.g) || 0;
           }
           const middle = vValue > hValue ? hValue : vValue;
-          setAlpha.call($this, colorBarL2, hValue > vValue ? toFixedNumeric(((hValue - vValue) / (255 - vValue)) * 100, 4) : 0);
-          setAlpha.call($this, colorBarL3, vValue > hValue ? toFixedNumeric(((vValue - hValue) / (255 - hValue)) * 100, 4) : 0);
-          setAlpha.call($this, colorBarL4, toFixedNumeric((middle / 255) * 100, 4));
-          setAlpha.call($this, colorBarL5, toFixedNumeric(((255 - ((rgba && rgba.a) || 0)) * 100) / 255, 4));
+          setAlpha.call(that, colorBarL2, hValue > vValue ? toFixedNumeric(((hValue - vValue) / (255 - vValue)) * 100, 4) : 0);
+          setAlpha.call(that, colorBarL3, vValue > hValue ? toFixedNumeric(((vValue - hValue) / (255 - hValue)) * 100, 4) : 0);
+          setAlpha.call(that, colorBarL4, toFixedNumeric((middle / 255) * 100, 4));
+          setAlpha.call(that, colorBarL5, toFixedNumeric(((255 - ((rgba && rgba.a) || 0)) * 100) / 255, 4));
           break;
-        case 'a': {
+        } case 'a': {
           const a = ui.val('a');
-          setBG.call($this, colorBarDiv, ui.val('hex') || '000000');
-          setAlpha.call($this, colorBarL5, a != null ? 0 : 100);
-          setAlpha.call($this, colorBarL6, a != null ? 100 : 0);
+          setBG.call(that, colorBarDiv, ui.val('hex') || '000000');
+          setAlpha.call(that, colorBarL5, !isNullish(a) ? 0 : 100);
+          setAlpha.call(that, colorBarL6, !isNullish(a) ? 100 : 0);
           break;
         }
         }
@@ -1426,7 +1470,7 @@ const jPicker = function ($) {
         if (alpha > 0 && alpha < 100) {
           if (isLessThanIE7) {
             const src = obj.attr('pngSrc');
-            if (src != null && (
+            if (!isNullish(src) && (
               src.includes('AlphaBar.png') || src.includes('Bars.png') || src.includes('Maps.png')
             )) {
               obj.css({filter: 'progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'' + src + '\', sizingMethod=\'scale\') progid:DXImageTransform.Microsoft.Alpha(opacity=' + alpha + ')'});
@@ -1435,7 +1479,7 @@ const jPicker = function ($) {
         } else if (alpha === 0 || alpha === 100) {
           if (isLessThanIE7) {
             const src = obj.attr('pngSrc');
-            if (src != null && (
+            if (!isNullish(src) && (
               src.includes('AlphaBar.png') || src.includes('Bars.png') || src.includes('Maps.png')
             )) {
               obj.css({filter: 'progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'' + src + '\', sizingMethod=\'scale\')'});
@@ -1453,38 +1497,38 @@ const jPicker = function ($) {
       }
       function radioClicked (e) {
         $(this).parents('tbody:first').find('input:radio[value!="' + e.target.value + '"]').removeAttr('checked');
-        setColorMode.call($this, e.target.value);
+        setColorMode.call(that, e.target.value);
       }
       function currentClicked () {
-        revertColor.call($this);
+        revertColor.call(that);
       }
       function cancelClicked () {
-        revertColor.call($this);
-        settings.window.expandable && hide.call($this);
-        typeof cancelCallback === 'function' && cancelCallback.call($this, color.active, cancelButton);
+        revertColor.call(that);
+        settings.window.expandable && hide.call(that);
+        typeof cancelCallback === 'function' && cancelCallback.call(that, color.active, cancelButton);
       }
       function okClicked () {
-        commitColor.call($this);
-        settings.window.expandable && hide.call($this);
-        typeof commitCallback === 'function' && commitCallback.call($this, color.active, okButton);
+        commitColor.call(that);
+        settings.window.expandable && hide.call(that);
+        typeof commitCallback === 'function' && commitCallback.call(that, color.active, okButton);
       }
       function iconImageClicked () {
-        show.call($this);
+        show.call(that);
       }
       function currentColorChanged (ui, context) {
         const hex = ui.val('hex');
         currentPreview.css({backgroundColor: (hex && '#' + hex) || 'transparent'});
-        setAlpha.call($this, currentPreview, toFixedNumeric(((ui.val('a') || 0) * 100) / 255, 4));
+        setAlpha.call(that, currentPreview, toFixedNumeric(((ui.val('a') || 0) * 100) / 255, 4));
       }
       function expandableColorChanged (ui, context) {
         const hex = ui.val('hex');
         const va = ui.val('va');
         iconColor.css({backgroundColor: (hex && '#' + hex) || 'transparent'});
-        setAlpha.call($this, iconAlpha, toFixedNumeric(((255 - ((va && va.a) || 0)) * 100) / 255, 4));
+        setAlpha.call(that, iconAlpha, toFixedNumeric(((255 - ((va && va.a) || 0)) * 100) / 255, 4));
         if (settings.window.bindToInput && settings.window.updateInputColor) {
           settings.window.input.css({
             backgroundColor: (hex && '#' + hex) || 'transparent',
-            color: va == null || va.v > 75 ? '#000000' : '#ffffff'
+            color: isNullish(va) || va.v > 75 ? '#000000' : '#ffffff'
           });
         }
       }
@@ -1564,11 +1608,11 @@ const jPicker = function ($) {
       }
       function initialize () {
         const win = settings.window,
-          popup = win.expandable ? $($this).next().find('.Container:first') : null;
-        container = win.expandable ? $('<div/>') : $($this);
+          popup = win.expandable ? $(that).next().find('.Container:first') : null;
+        container = win.expandable ? $('<div/>') : $(that);
         container.addClass('jPicker Container');
         if (win.expandable) container.hide();
-        container.get(0).onselectstart = function (event) { if (event.target.nodeName.toLowerCase() !== 'input') return false; };
+        container.get(0).onselectstart = function (e) { if (e.target.nodeName.toLowerCase() !== 'input') return false; };
         // inject html source code - we are using a single table for this control - I know tables are considered bad, but it takes care of equal height columns and
         // this control really is tabular data, so I believe it is the right move
         const all = color.active.val('all');
@@ -1585,34 +1629,34 @@ const jPicker = function ($) {
             </tr>
             <tr class="Hue">
               <td class="Radio"><label title="${localization.tooltips.hue.radio}"><input type="radio" value="h"${settings.color.mode === 'h' ? ' checked="checked"' : ''}/>H:</label></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.h : ''}" title="${localization.tooltips.hue.textbox}"/>&nbsp;&deg;</td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.h : ''}" title="${localization.tooltips.hue.textbox}"/>&nbsp;&deg;</td>
             </tr>
             <tr class="Saturation">
               <td class="Radio"><label title="${localization.tooltips.saturation.radio}"><input type="radio" value="s"${settings.color.mode === 's' ? ' checked="checked"' : ''}/>S:</label></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.s : ''}" title="${localization.tooltips.saturation.textbox}"/>&nbsp;%</td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.s : ''}" title="${localization.tooltips.saturation.textbox}"/>&nbsp;%</td>
             </tr>
             <tr class="Value">
               <td class="Radio"><label title="${localization.tooltips.value.radio}"><input type="radio" value="v"${settings.color.mode === 'v' ? ' checked="checked"' : ''}/>V:</label><br/><br/></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.v : ''}" title="${localization.tooltips.value.textbox}"/>&nbsp;%<br/><br/></td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.v : ''}" title="${localization.tooltips.value.textbox}"/>&nbsp;%<br/><br/></td>
             </tr>
             <tr class="Red">
               <td class="Radio"><label title="${localization.tooltips.red.radio}"><input type="radio" value="r"${settings.color.mode === 'r' ? ' checked="checked"' : ''}/>R:</label></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.r : ''}" title="${localization.tooltips.red.textbox}"/></td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.r : ''}" title="${localization.tooltips.red.textbox}"/></td>
             </tr>
             <tr class="Green">
               <td class="Radio"><label title="${localization.tooltips.green.radio}"><input type="radio" value="g"${settings.color.mode === 'g' ? ' checked="checked"' : ''}/>G:</label></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.g : ''}" title="${localization.tooltips.green.textbox}"/></td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.g : ''}" title="${localization.tooltips.green.textbox}"/></td>
             </tr>
             <tr class="Blue">
               <td class="Radio"><label title="${localization.tooltips.blue.radio}"><input type="radio" value="b"${settings.color.mode === 'b' ? ' checked="checked"' : ''}/>B:</label></td>
-              <td class="Text"><input type="text" maxlength="3" value="${all != null ? all.b : ''}" title="${localization.tooltips.blue.textbox}"/></td>
+              <td class="Text"><input type="text" maxlength="3" value="${!isNullish(all) ? all.b : ''}" title="${localization.tooltips.blue.textbox}"/></td>
             </tr>
             <tr class="Alpha">
               <td class="Radio">${win.alphaSupport ? `<label title="${localization.tooltips.alpha.radio}"><input type="radio" value="a"${settings.color.mode === 'a' ? ' checked="checked"' : ''}/>A:</label>` : '&nbsp;'}</td>
-              <td class="Text">${win.alphaSupport ? `<input type="text" maxlength="${3 + win.alphaPrecision}" value="${all != null ? toFixedNumeric((all.a * 100) / 255, win.alphaPrecision) : ''}" title="${localization.tooltips.alpha.textbox}"/>&nbsp;%` : '&nbsp;'}</td>
+              <td class="Text">${win.alphaSupport ? `<input type="text" maxlength="${3 + win.alphaPrecision}" value="${!isNullish(all) ? toFixedNumeric((all.a * 100) / 255, win.alphaPrecision) : ''}" title="${localization.tooltips.alpha.textbox}"/>&nbsp;%` : '&nbsp;'}</td>
             </tr>
             <tr class="Hex">
-              <td colspan="2" class="Text"><label title="${localization.tooltips.hex.textbox}">#:<input type="text" maxlength="6" class="Hex" value="${all != null ? all.hex : ''}"/></label>${win.alphaSupport ? `<input type="text" maxlength="2" class="AHex" value="${all != null ? all.ahex.substring(6) : ''}" title="${localization.tooltips.hex.alpha}"/></td>` : '&nbsp;'}
+              <td colspan="2" class="Text"><label title="${localization.tooltips.hex.textbox}">#:<input type="text" maxlength="6" class="Hex" value="${!isNullish(all) ? all.hex : ''}"/></label>${win.alphaSupport ? `<input type="text" maxlength="2" class="AHex" value="${!isNullish(all) ? all.ahex.substring(6) : ''}" title="${localization.tooltips.hex.alpha}"/></td>` : '&nbsp;'}
             </tr>
           </tbody></table>`;
         if (win.expandable) {
@@ -1626,7 +1670,8 @@ const jPicker = function ($) {
             function () {
               $(document.body).children('div.jPicker.Container').css({zIndex: 10});
               container.css({zIndex: 20});
-            });
+            }
+          );
           container.css( // positions must be set and display set to absolute before source code injection or IE will size the container to fit the window
             {
               left:
@@ -1647,9 +1692,10 @@ const jPicker = function ($) {
                   : win.position.y === 'bottom'
                     ? (popup.offset().top + 25) + 'px'
                     : (popup.offset().top + parseInt(win.position.y)) + 'px'
-            });
+            }
+          );
         } else {
-          container = $($this);
+          container = $(that);
           container.html(controlHtml);
         }
         // initialize the objects to the source code just injected
@@ -1668,7 +1714,8 @@ const jPicker = function ($) {
         colorBarL5 = BarMaps.filter('.Map5:first');
         colorBarL6 = BarMaps.filter('.Map6:first');
         // create color pickers and maps
-        colorMap = new Slider(colorMapDiv,
+        colorMap = new Slider(
+          colorMapDiv,
           {
             map: {
               width: images.colorMap.width,
@@ -1682,7 +1729,8 @@ const jPicker = function ($) {
           }
         );
         colorMap.bind(mapValueChanged);
-        colorBar = new Slider(colorBarDiv,
+        colorBar = new Slider(
+          colorBarDiv,
           {
             map: {
               width: images.colorBar.width,
@@ -1701,26 +1749,26 @@ const jPicker = function ($) {
           color.active,
           win.expandable && win.bindToInput ? win.input : null, win.alphaPrecision
         );
-        const hex = all != null ? all.hex : null,
+        const hex = !isNullish(all) ? all.hex : null,
           preview = tbody.find('.Preview'),
           button = tbody.find('.Button');
         activePreview = preview.find('.Active:first').css({backgroundColor: (hex && '#' + hex) || 'transparent'});
         currentPreview = preview.find('.Current:first').css({backgroundColor: (hex && '#' + hex) || 'transparent'}).bind('click', currentClicked);
-        setAlpha.call($this, currentPreview, toFixedNumeric((color.current.val('a') * 100) / 255, 4));
+        setAlpha.call(that, currentPreview, toFixedNumeric((color.current.val('a') * 100) / 255, 4));
         okButton = button.find('.Ok:first').bind('click', okClicked);
         cancelButton = button.find('.Cancel:first').bind('click', cancelClicked);
         grid = button.find('.Grid:first');
         setTimeout(function () {
-          setImg.call($this, colorMapL1, images.clientPath + 'Maps.png');
-          setImg.call($this, colorMapL2, images.clientPath + 'Maps.png');
-          setImg.call($this, colorMapL3, images.clientPath + 'map-opacity.png');
-          setImg.call($this, colorBarL1, images.clientPath + 'Bars.png');
-          setImg.call($this, colorBarL2, images.clientPath + 'Bars.png');
-          setImg.call($this, colorBarL3, images.clientPath + 'Bars.png');
-          setImg.call($this, colorBarL4, images.clientPath + 'Bars.png');
-          setImg.call($this, colorBarL5, images.clientPath + 'bar-opacity.png');
-          setImg.call($this, colorBarL6, images.clientPath + 'AlphaBar.png');
-          setImg.call($this, preview.find('div:first'), images.clientPath + 'preview-opacity.png');
+          setImg.call(that, colorMapL1, images.clientPath + 'Maps.png');
+          setImg.call(that, colorMapL2, images.clientPath + 'Maps.png');
+          setImg.call(that, colorMapL3, images.clientPath + 'map-opacity.png');
+          setImg.call(that, colorBarL1, images.clientPath + 'Bars.png');
+          setImg.call(that, colorBarL2, images.clientPath + 'Bars.png');
+          setImg.call(that, colorBarL3, images.clientPath + 'Bars.png');
+          setImg.call(that, colorBarL4, images.clientPath + 'Bars.png');
+          setImg.call(that, colorBarL5, images.clientPath + 'bar-opacity.png');
+          setImg.call(that, colorBarL6, images.clientPath + 'AlphaBar.png');
+          setImg.call(that, preview.find('div:first'), images.clientPath + 'preview-opacity.png');
         }, 0);
         tbody.find('td.Radio input').bind('click', radioClicked);
         // initialize quick list
@@ -1736,33 +1784,33 @@ const jPicker = function ($) {
             if (!ahex) ahex = '00000000';
             html += '<span class="QuickColor"' + (' title="#' + ahex + '"') + ' style="background-color:' + ((quickHex && '#' + quickHex) || '') + ';' + (quickHex ? '' : 'background-image:url(' + images.clientPath + 'NoColor.png)') + (win.alphaSupport && alpha && alpha < 255 ? ';opacity:' + toFixedNumeric(alpha / 255, 4) + ';filter:Alpha(opacity=' + toFixedNumeric(alpha / 2.55, 4) + ')' : '') + '">&nbsp;</span>';
           }
-          setImg.call($this, grid, images.clientPath + 'bar-opacity.png');
+          setImg.call(that, grid, images.clientPath + 'bar-opacity.png');
           grid.html(html);
           grid.find('.QuickColor').click(quickPickClicked);
         }
-        setColorMode.call($this, settings.color.mode);
+        setColorMode.call(that, settings.color.mode);
         color.active.bind(activeColorChanged);
         typeof liveCallback === 'function' && color.active.bind(liveCallback);
         color.current.bind(currentColorChanged);
         // bind to input
         if (win.expandable) {
-          $this.icon = popup.parents('.Icon:first');
-          iconColor = $this.icon.find('.Color:first').css({backgroundColor: (hex && '#' + hex) || 'transparent'});
-          iconAlpha = $this.icon.find('.Alpha:first');
-          setImg.call($this, iconAlpha, images.clientPath + 'bar-opacity.png');
-          setAlpha.call($this, iconAlpha, toFixedNumeric(((255 - (all != null ? all.a : 0)) * 100) / 255, 4));
-          iconImage = $this.icon.find('.Image:first').css({
+          that.icon = popup.parents('.Icon:first');
+          iconColor = that.icon.find('.Color:first').css({backgroundColor: (hex && '#' + hex) || 'transparent'});
+          iconAlpha = that.icon.find('.Alpha:first');
+          setImg.call(that, iconAlpha, images.clientPath + 'bar-opacity.png');
+          setAlpha.call(that, iconAlpha, toFixedNumeric(((255 - (!isNullish(all) ? all.a : 0)) * 100) / 255, 4));
+          iconImage = that.icon.find('.Image:first').css({
             backgroundImage: 'url(\'' + images.clientPath + images.picker.file + '\')'
           }).bind('click', iconImageClicked);
           if (win.bindToInput && win.updateInputColor) {
             win.input.css({
               backgroundColor: (hex && '#' + hex) || 'transparent',
-              color: all == null || all.v > 75 ? '#000000' : '#ffffff'
+              color: isNullish(all) || all.v > 75 ? '#000000' : '#ffffff'
             });
           }
           moveBar = tbody.find('.Move:first').bind('mousedown', moveBarMouseDown);
           color.active.bind(expandableColorChanged);
-        } else show.call($this);
+        } else show.call(that);
       }
       function destroy () {
         container.find('td.Radio input').unbind('click', radioClicked);
@@ -1772,7 +1820,7 @@ const jPicker = function ($) {
         if (settings.window.expandable) {
           iconImage.unbind('click', iconImageClicked);
           moveBar.unbind('mousedown', moveBarMouseDown);
-          $this.icon = null;
+          that.icon = null;
         }
         container.find('.QuickColor').unbind('click', quickPickClicked);
         colorMapDiv = null;
@@ -1802,7 +1850,7 @@ const jPicker = function ($) {
         liveCallback = null;
         container.html('');
         for (let i = 0; i < List.length; i++) {
-          if (List[i] === $this) {
+          if (List[i] === that) {
             List.splice(i, 1);
           }
         }
@@ -1831,6 +1879,16 @@ const jPicker = function ($) {
         quickList: settings.color.quickList
       };
 
+      if (typeof commitCallback !== 'function') {
+        commitCallback = null;
+      }
+      if (typeof liveCallback !== 'function') {
+        liveCallback = null;
+      }
+      if (typeof cancelCallback !== 'function') {
+        cancelCallback = null;
+      }
+
       let elementStartX = null, // Used to record the starting css positions for dragging the control
         elementStartY = null,
         pageStartX = null, // Used to record the mousedown coordinates for dragging the control
@@ -1858,12 +1916,9 @@ const jPicker = function ($) {
         iconColor = null, // iconColor for popup icon
         iconAlpha = null, // iconAlpha for popup icon
         iconImage = null, // iconImage popup icon
-        moveBar = null, // drag bar
-        commitCallback = typeof $arguments[1] === 'function' ? $arguments[1] : null,
-        liveCallback = typeof $arguments[2] === 'function' ? $arguments[2] : null,
-        cancelCallback = typeof $arguments[3] === 'function' ? $arguments[3] : null;
+        moveBar = null; // drag bar
 
-      $.extend(true, $this, {
+      $.extend(true, that, {
         // public properties, methods, and callbacks
         commitCallback, // commitCallback function can be overridden to return the selected color to a method you specify when the user clicks "OK"
         liveCallback, // liveCallback function can be overridden to return the selected color to a method you specify in live mode (continuous update)
@@ -1873,9 +1928,9 @@ const jPicker = function ($) {
         hide,
         destroy // destroys this control entirely, removing all events and objects, and removing itself from the List
       });
-      List.push($this);
+      List.push(that);
       setTimeout(function () {
-        initialize.call($this);
+        initialize.call(that);
       }, 0);
     });
   };
diff --git a/editor/jspdf/jspdf.plugin.svgToPdf.js b/editor/jspdf/jspdf.plugin.svgToPdf.js
index c608a77f..41c07fe3 100644
--- a/editor/jspdf/jspdf.plugin.svgToPdf.js
+++ b/editor/jspdf/jspdf.plugin.svgToPdf.js
@@ -106,7 +106,7 @@ const svgElementToPdf = function (element, pdf, options) {
         pdf.setFillColor(fillRGB.r, fillRGB.g, fillRGB.b);
       }
       if (attributeIsNotEmpty(node, 'stroke-width')) {
-        pdf.setLineWidth(k * parseInt(node.getAttribute('stroke-width'), 10));
+        pdf.setLineWidth(k * parseInt(node.getAttribute('stroke-width')));
       }
       const strokeColor = node.getAttribute('stroke');
       if (attributeIsNotEmpty(strokeColor)) {
@@ -134,38 +134,38 @@ const svgElementToPdf = function (element, pdf, options) {
       break;
     case 'line':
       pdf.line(
-        k * parseInt(node.getAttribute('x1'), 10),
-        k * parseInt(node.getAttribute('y1'), 10),
-        k * parseInt(node.getAttribute('x2'), 10),
-        k * parseInt(node.getAttribute('y2'), 10)
+        k * parseInt(node.getAttribute('x1')),
+        k * parseInt(node.getAttribute('y1')),
+        k * parseInt(node.getAttribute('x2')),
+        k * parseInt(node.getAttribute('y2'))
       );
       removeAttributes(node, pdfSvgAttr.line);
       break;
     case 'rect':
       pdf.rect(
-        k * parseInt(node.getAttribute('x'), 10),
-        k * parseInt(node.getAttribute('y'), 10),
-        k * parseInt(node.getAttribute('width'), 10),
-        k * parseInt(node.getAttribute('height'), 10),
+        k * parseInt(node.getAttribute('x')),
+        k * parseInt(node.getAttribute('y')),
+        k * parseInt(node.getAttribute('width')),
+        k * parseInt(node.getAttribute('height')),
         colorMode
       );
       removeAttributes(node, pdfSvgAttr.rect);
       break;
     case 'ellipse':
       pdf.ellipse(
-        k * parseInt(node.getAttribute('cx'), 10),
-        k * parseInt(node.getAttribute('cy'), 10),
-        k * parseInt(node.getAttribute('rx'), 10),
-        k * parseInt(node.getAttribute('ry'), 10),
+        k * parseInt(node.getAttribute('cx')),
+        k * parseInt(node.getAttribute('cy')),
+        k * parseInt(node.getAttribute('rx')),
+        k * parseInt(node.getAttribute('ry')),
         colorMode
       );
       removeAttributes(node, pdfSvgAttr.ellipse);
       break;
     case 'circle':
       pdf.circle(
-        k * parseInt(node.getAttribute('cx'), 10),
-        k * parseInt(node.getAttribute('cy'), 10),
-        k * parseInt(node.getAttribute('r'), 10),
+        k * parseInt(node.getAttribute('cx')),
+        k * parseInt(node.getAttribute('cy')),
+        k * parseInt(node.getAttribute('r')),
         colorMode
       );
       removeAttributes(node, pdfSvgAttr.circle);
@@ -216,7 +216,7 @@ const svgElementToPdf = function (element, pdf, options) {
       }
       pdf.setFontType(fontType);
       const pdfFontSize = node.hasAttribute('font-size')
-        ? parseInt(node.getAttribute('font-size'), 10)
+        ? parseInt(node.getAttribute('font-size'))
         : 16;
 
       const getWidth = (node) => {
@@ -247,8 +247,8 @@ const svgElementToPdf = function (element, pdf, options) {
         case 'start': break;
         case 'default': node.setAttribute('text-anchor', 'start'); break;
         }
-        x = parseInt(node.getAttribute('x'), 10) - xOffset;
-        y = parseInt(node.getAttribute('y'), 10);
+        x = parseInt(node.getAttribute('x')) - xOffset;
+        y = parseInt(node.getAttribute('y'));
       }
       // console.log('fontSize:', pdfFontSize, 'text:', node.textContent);
       pdf.setFontSize(pdfFontSize).text(
diff --git a/editor/layer.js b/editor/layer.js
index cc3ca743..37446815 100644
--- a/editor/layer.js
+++ b/editor/layer.js
@@ -8,7 +8,7 @@
  */
 
 import {NS} from './namespaces.js';
-import {toXml, walkTree} from './utilities.js';
+import {toXml, walkTree, isNullish} from './utilities.js';
 
 const $ = jQuery;
 
@@ -117,7 +117,7 @@ class Layer {
    */
   getOpacity () {
     const opacity = this.group_.getAttribute('opacity');
-    if (opacity === null || opacity === undefined) {
+    if (isNullish(opacity)) {
       return 1;
     }
     return parseFloat(opacity);
@@ -212,7 +212,7 @@ Layer.CLASS_REGEX = new RegExp('(\\s|^)' + Layer.CLASS_NAME + '(\\s|$)');
  */
 function addLayerClass (elem) {
   const classes = elem.getAttribute('class');
-  if (classes === null || classes === undefined || !classes.length) {
+  if (isNullish(classes) || !classes.length) {
     elem.setAttribute('class', Layer.CLASS_NAME);
   } else if (!Layer.CLASS_REGEX.test(classes)) {
     elem.setAttribute('class', classes + ' ' + Layer.CLASS_NAME);
diff --git a/editor/locale/lang.af.js b/editor/locale/lang.af.js
index dbabcc85..86c8ece9 100644
--- a/editor/locale/lang.af.js
+++ b/editor/locale/lang.af.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ar.js b/editor/locale/lang.ar.js
index 67fd7126..6746c0bf 100644
--- a/editor/locale/lang.ar.js
+++ b/editor/locale/lang.ar.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.az.js b/editor/locale/lang.az.js
index 2def669a..f6455252 100644
--- a/editor/locale/lang.az.js
+++ b/editor/locale/lang.az.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.be.js b/editor/locale/lang.be.js
index 7d16a3b3..87d02fc1 100644
--- a/editor/locale/lang.be.js
+++ b/editor/locale/lang.be.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.bg.js b/editor/locale/lang.bg.js
index 7904f3eb..2fa3dc2a 100644
--- a/editor/locale/lang.bg.js
+++ b/editor/locale/lang.bg.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ca.js b/editor/locale/lang.ca.js
index 00ef0653..e46a7edb 100644
--- a/editor/locale/lang.ca.js
+++ b/editor/locale/lang.ca.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.cs.js b/editor/locale/lang.cs.js
index 85575a6a..3e420ffe 100644
--- a/editor/locale/lang.cs.js
+++ b/editor/locale/lang.cs.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.cy.js b/editor/locale/lang.cy.js
index 3c37326a..683b8def 100644
--- a/editor/locale/lang.cy.js
+++ b/editor/locale/lang.cy.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.da.js b/editor/locale/lang.da.js
index 8ced17ca..f1699e5a 100644
--- a/editor/locale/lang.da.js
+++ b/editor/locale/lang.da.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.de.js b/editor/locale/lang.de.js
index 1ae14c0a..76bf6201 100644
--- a/editor/locale/lang.de.js
+++ b/editor/locale/lang.de.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'Es sind nicht-gespeicherte Änderungen vorhanden.',
     enterNewLinkURL: 'Geben Sie die neue URL ein',
     errorLoadingSVG: 'Fehler: Kann SVG-Daten nicht laden',
-    URLloadFail: 'Kann von dieser URL nicht laden',
+    URLLoadFail: 'Kann von dieser URL nicht laden',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.el.js b/editor/locale/lang.el.js
index a429dfd6..b7a72441 100644
--- a/editor/locale/lang.el.js
+++ b/editor/locale/lang.el.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.en.js b/editor/locale/lang.en.js
index 204c8488..3dc5458b 100644
--- a/editor/locale/lang.en.js
+++ b/editor/locale/lang.en.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.es.js b/editor/locale/lang.es.js
index a07ea660..98739708 100644
--- a/editor/locale/lang.es.js
+++ b/editor/locale/lang.es.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.et.js b/editor/locale/lang.et.js
index e5bd4c5b..c98d6810 100644
--- a/editor/locale/lang.et.js
+++ b/editor/locale/lang.et.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.fa.js b/editor/locale/lang.fa.js
index 912e1086..d6f241c3 100644
--- a/editor/locale/lang.fa.js
+++ b/editor/locale/lang.fa.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.fi.js b/editor/locale/lang.fi.js
index 4397616d..12af7ca4 100644
--- a/editor/locale/lang.fi.js
+++ b/editor/locale/lang.fi.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: "Retrieving '%s' ...",
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.fr.js b/editor/locale/lang.fr.js
index 92dbbfdc..e04073e8 100644
--- a/editor/locale/lang.fr.js
+++ b/editor/locale/lang.fr.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'Il y a des changements non sauvegardés.',
     enterNewLinkURL: "Entrez la nouvelle URL de l'hyperlien",
     errorLoadingSVG: 'Erreur : Impossible de charger les données SVG',
-    URLloadFail: "Impossible de charger l'URL",
+    URLLoadFail: "Impossible de charger l'URL",
     retrieving: 'Récupération de « %s »…',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.fy.js b/editor/locale/lang.fy.js
index bdcb0ff7..e75046dd 100644
--- a/editor/locale/lang.fy.js
+++ b/editor/locale/lang.fy.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\'...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ga.js b/editor/locale/lang.ga.js
index 560c5c9c..298d8741 100644
--- a/editor/locale/lang.ga.js
+++ b/editor/locale/lang.ga.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.gl.js b/editor/locale/lang.gl.js
index 85d1be54..57524c92 100644
--- a/editor/locale/lang.gl.js
+++ b/editor/locale/lang.gl.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.he.js b/editor/locale/lang.he.js
index f9b08f97..91c1e0de 100755
--- a/editor/locale/lang.he.js
+++ b/editor/locale/lang.he.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.hi.js b/editor/locale/lang.hi.js
index e9558ac2..e5fe2343 100644
--- a/editor/locale/lang.hi.js
+++ b/editor/locale/lang.hi.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.hr.js b/editor/locale/lang.hr.js
index f6459678..40cebeb3 100644
--- a/editor/locale/lang.hr.js
+++ b/editor/locale/lang.hr.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.hu.js b/editor/locale/lang.hu.js
index 89d96c3c..7c1acb9c 100644
--- a/editor/locale/lang.hu.js
+++ b/editor/locale/lang.hu.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.hy.js b/editor/locale/lang.hy.js
index 1a5a9adc..16931a06 100644
--- a/editor/locale/lang.hy.js
+++ b/editor/locale/lang.hy.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.id.js b/editor/locale/lang.id.js
index 02e17e0e..4c6d418b 100644
--- a/editor/locale/lang.id.js
+++ b/editor/locale/lang.id.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.is.js b/editor/locale/lang.is.js
index af88bb90..56c79e91 100644
--- a/editor/locale/lang.is.js
+++ b/editor/locale/lang.is.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.it.js b/editor/locale/lang.it.js
index c6cbbf71..cce861c1 100644
--- a/editor/locale/lang.it.js
+++ b/editor/locale/lang.it.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ja.js b/editor/locale/lang.ja.js
index 23d0df6a..cd139bee 100644
--- a/editor/locale/lang.ja.js
+++ b/editor/locale/lang.ja.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ko.js b/editor/locale/lang.ko.js
index 48a407f4..e22c15ec 100644
--- a/editor/locale/lang.ko.js
+++ b/editor/locale/lang.ko.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.lt.js b/editor/locale/lang.lt.js
index 6c16e56a..a89d2341 100644
--- a/editor/locale/lang.lt.js
+++ b/editor/locale/lang.lt.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.lv.js b/editor/locale/lang.lv.js
index 19ee6080..db0ac8aa 100644
--- a/editor/locale/lang.lv.js
+++ b/editor/locale/lang.lv.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.mk.js b/editor/locale/lang.mk.js
index b3da97d9..cb09ff71 100644
--- a/editor/locale/lang.mk.js
+++ b/editor/locale/lang.mk.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ms.js b/editor/locale/lang.ms.js
index 6352de6c..7af353fb 100644
--- a/editor/locale/lang.ms.js
+++ b/editor/locale/lang.ms.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.mt.js b/editor/locale/lang.mt.js
index a6ba800c..ca186c94 100644
--- a/editor/locale/lang.mt.js
+++ b/editor/locale/lang.mt.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.nl.js b/editor/locale/lang.nl.js
index c4d29123..40adf6af 100644
--- a/editor/locale/lang.nl.js
+++ b/editor/locale/lang.nl.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.no.js b/editor/locale/lang.no.js
index 78847aa0..c33c4731 100644
--- a/editor/locale/lang.no.js
+++ b/editor/locale/lang.no.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.pl.js b/editor/locale/lang.pl.js
index e77d9c21..755902a6 100644
--- a/editor/locale/lang.pl.js
+++ b/editor/locale/lang.pl.js
@@ -207,7 +207,7 @@ export default {
     unsavedChanges: 'Wykryto niezapisane zmiany.',
     enterNewLinkURL: 'Wpisz nowy adres URL hiperłącza',
     errorLoadingSVG: 'Błąd: Nie można załadować danych SVG',
-    URLloadFail: 'Nie można załadować z adresu URL',
+    URLLoadFail: 'Nie można załadować z adresu URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.pt-BR.js b/editor/locale/lang.pt-BR.js
index 29dd84ef..265f7cab 100644
--- a/editor/locale/lang.pt-BR.js
+++ b/editor/locale/lang.pt-BR.js
@@ -205,7 +205,7 @@ export default {
     unsavedChanges: 'Existem alterações não salvas.',
     enterNewLinkURL: 'Insira novo URL do hyperlink',
     errorLoadingSVG: 'Erro: Impossível carregar dados SVG',
-    URLloadFail: 'Impossível carregar deste URL',
+    URLLoadFail: 'Impossível carregar deste URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.pt-PT.js b/editor/locale/lang.pt-PT.js
index 8b187eaf..fe358ae2 100644
--- a/editor/locale/lang.pt-PT.js
+++ b/editor/locale/lang.pt-PT.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ro.js b/editor/locale/lang.ro.js
index e7c82ad7..1e6c3175 100644
--- a/editor/locale/lang.ro.js
+++ b/editor/locale/lang.ro.js
@@ -205,7 +205,7 @@ export default {
     unsavedChanges: 'Sunt schimbări nesalvate.',
     enterNewLinkURL: 'IntroduAliniere în raport cu ...sceţi noul URL',
     errorLoadingSVG: 'Eroare: Nu se pot încărca datele SVG',
-    URLloadFail: 'Nu se poate încărca de la URL',
+    URLLoadFail: 'Nu se poate încărca de la URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.ru.js b/editor/locale/lang.ru.js
index e5ae878a..1dff0cf1 100644
--- a/editor/locale/lang.ru.js
+++ b/editor/locale/lang.ru.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sk.js b/editor/locale/lang.sk.js
index ee04cde2..833244f5 100644
--- a/editor/locale/lang.sk.js
+++ b/editor/locale/lang.sk.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'Sú tu neuložené zmeny.',
     enterNewLinkURL: 'Zadajte nové URL odkazu (hyperlink)',
     errorLoadingSVG: 'Chyba: Nedajú sa načítať SVG data',
-    URLloadFail: 'Nemožno čítať z URL',
+    URLLoadFail: 'Nemožno čítať z URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sl.js b/editor/locale/lang.sl.js
index a72c3715..42cf787a 100644
--- a/editor/locale/lang.sl.js
+++ b/editor/locale/lang.sl.js
@@ -205,7 +205,7 @@ export default {
     unsavedChanges: 'Obstajajo neshranjene spremembe.',
     enterNewLinkURL: 'Vnesite novo URL povezavo',
     errorLoadingSVG: 'Napaka: Ne morem naložiti SVG podatkov',
-    URLloadFail: 'Ne morem naložiti z URL',
+    URLLoadFail: 'Ne morem naložiti z URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sq.js b/editor/locale/lang.sq.js
index 01782fde..d224ba2e 100644
--- a/editor/locale/lang.sq.js
+++ b/editor/locale/lang.sq.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sr.js b/editor/locale/lang.sr.js
index a7d466fa..4c3b80e5 100644
--- a/editor/locale/lang.sr.js
+++ b/editor/locale/lang.sr.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sv.js b/editor/locale/lang.sv.js
index fcf98153..7a618ca4 100644
--- a/editor/locale/lang.sv.js
+++ b/editor/locale/lang.sv.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.sw.js b/editor/locale/lang.sw.js
index e97c8e1c..6ff7f4db 100644
--- a/editor/locale/lang.sw.js
+++ b/editor/locale/lang.sw.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.test.js b/editor/locale/lang.test.js
index 92f0e0f2..c30e3484 100644
--- a/editor/locale/lang.test.js
+++ b/editor/locale/lang.test.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.th.js b/editor/locale/lang.th.js
index 876fdf64..7c3fff53 100644
--- a/editor/locale/lang.th.js
+++ b/editor/locale/lang.th.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.tl.js b/editor/locale/lang.tl.js
index 06963af4..b1af0649 100644
--- a/editor/locale/lang.tl.js
+++ b/editor/locale/lang.tl.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.tr.js b/editor/locale/lang.tr.js
index 309c25bf..e6dc64bd 100644
--- a/editor/locale/lang.tr.js
+++ b/editor/locale/lang.tr.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.uk.js b/editor/locale/lang.uk.js
index 79244a47..05bba17f 100644
--- a/editor/locale/lang.uk.js
+++ b/editor/locale/lang.uk.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.vi.js b/editor/locale/lang.vi.js
index 2a119caa..17ea015a 100644
--- a/editor/locale/lang.vi.js
+++ b/editor/locale/lang.vi.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.yi.js b/editor/locale/lang.yi.js
index 4e42e20b..87e83305 100644
--- a/editor/locale/lang.yi.js
+++ b/editor/locale/lang.yi.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.zh-CN.js b/editor/locale/lang.zh-CN.js
index caa03d08..bff08635 100644
--- a/editor/locale/lang.zh-CN.js
+++ b/editor/locale/lang.zh-CN.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: '存在未保存的修改.',
     enterNewLinkURL: '输入新建链接的URL地址',
     errorLoadingSVG: '错误: 无法加载SVG数据',
-    URLloadFail: '无法从URL中加载',
+    URLLoadFail: '无法从URL中加载',
     retrieving: '检索 \'%s\'...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.zh-HK.js b/editor/locale/lang.zh-HK.js
index e2e821f1..71d85844 100644
--- a/editor/locale/lang.zh-HK.js
+++ b/editor/locale/lang.zh-HK.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/lang.zh-TW.js b/editor/locale/lang.zh-TW.js
index 1e544bfa..98d3e30a 100644
--- a/editor/locale/lang.zh-TW.js
+++ b/editor/locale/lang.zh-TW.js
@@ -206,7 +206,7 @@ export default {
     unsavedChanges: 'There are unsaved changes.',
     enterNewLinkURL: 'Enter the new hyperlink URL',
     errorLoadingSVG: 'Error: Unable to load SVG data',
-    URLloadFail: 'Unable to load from URL',
+    URLLoadFail: 'Unable to load from URL',
     retrieving: 'Retrieving \'%s\' ...',
     popupWindowBlocked: 'Popup window may be blocked by browser',
     exportNoBlur: 'Blurred elements will appear as un-blurred',
diff --git a/editor/locale/locale.js b/editor/locale/locale.js
index d523d5d0..e65cd074 100644
--- a/editor/locale/locale.js
+++ b/editor/locale/locale.js
@@ -223,7 +223,7 @@ export const readLang = async function (langData) {
     image_width: properties.image_width,
     layer_delete: layers.del,
     layer_down: layers.move_down,
-    layer_new: layers['new'],
+    layer_new: layers.new,
     layer_rename: layers.rename,
     layer_moreopts: common.more_opts,
     layer_up: layers.move_up,
diff --git a/editor/math.js b/editor/math.js
index f1c27c57..44c16029 100644
--- a/editor/math.js
+++ b/editor/math.js
@@ -21,6 +21,7 @@
 
 import {NS} from './namespaces.js';
 import {getTransformList} from './svgtransformlist.js';
+import {isNullish} from './utilities.js';
 
 // Constants
 const NEAR_ZERO = 1e-14;
@@ -151,14 +152,14 @@ export const transformBox = function (l, t, w, h, m) {
  * @returns {SVGTransform} A single matrix transform object
 */
 export const transformListToTransform = function (tlist, min, max) {
-  if (tlist == null) {
+  if (isNullish(tlist)) {
     // Or should tlist = null have been prevented before this?
     return svg.createSVGTransformFromMatrix(svg.createSVGMatrix());
   }
   min = min || 0;
   max = max || (tlist.numberOfItems - 1);
-  min = parseInt(min, 10);
-  max = parseInt(max, 10);
+  min = parseInt(min);
+  max = parseInt(max);
   if (min > max) { const temp = max; max = min; min = temp; }
   let m = svg.createSVGMatrix();
   for (let i = min; i <= max; ++i) {
diff --git a/editor/path.js b/editor/path.js
index 8e6d102d..12912c06 100644
--- a/editor/path.js
+++ b/editor/path.js
@@ -18,7 +18,7 @@ import {
 } from './math.js';
 import {
   assignAttributes, getElem, getRotationAngle, getBBox,
-  getRefElem, findDefs, snapToGrid,
+  getRefElem, findDefs, snapToGrid, isNullish,
   getBBox as utilsGetBBox
 } from './utilities.js';
 import {
@@ -77,7 +77,7 @@ export const setLinkControlPoints = function (lcp) {
  * @type {null|module:path.Path}
  * @memberof module:path
 */
-export let path = null;
+export let path = null; // eslint-disable-line import/no-mutable-exports
 
 let editorContext_ = null;
 
@@ -240,8 +240,10 @@ export const init = function (editorContext) {
   editorContext_ = editorContext;
 
   pathFuncs = [0, 'ClosePath'];
-  const pathFuncsStrs = ['Moveto', 'Lineto', 'CurvetoCubic', 'CurvetoQuadratic', 'Arc',
-    'LinetoHorizontal', 'LinetoVertical', 'CurvetoCubicSmooth', 'CurvetoQuadraticSmooth'];
+  const pathFuncsStrs = [
+    'Moveto', 'Lineto', 'CurvetoCubic', 'CurvetoQuadratic', 'Arc',
+    'LinetoHorizontal', 'LinetoVertical', 'CurvetoCubicSmooth', 'CurvetoQuadraticSmooth'
+  ];
   $.each(pathFuncsStrs, function (i, s) {
     pathFuncs.push(s + 'Abs');
     pathFuncs.push(s + 'Rel');
@@ -299,14 +301,14 @@ export const ptObjToArr = function (type, segItem) {
 * @returns {module:math.XYObject}
 */
 export const getGripPt = function (seg, altPt) {
-  const {path} = seg;
+  const {path: pth} = seg;
   let out = {
     x: altPt ? altPt.x : seg.item.x,
     y: altPt ? altPt.y : seg.item.y
   };
 
-  if (path.matrix) {
-    const pt = transformPoint(out.x, out.y, path.matrix);
+  if (pth.matrix) {
+    const pt = transformPoint(out.x, out.y, pth.matrix);
     out = pt;
   }
 
@@ -320,17 +322,17 @@ export const getGripPt = function (seg, altPt) {
 /**
 * @function module:path.getPointFromGrip
 * @param {module:math.XYObject} pt
-* @param {module:path.Path} path
+* @param {module:path.Path} pth
 * @returns {module:math.XYObject}
 */
-export const getPointFromGrip = function (pt, path) {
+export const getPointFromGrip = function (pt, pth) {
   const out = {
     x: pt.x,
     y: pt.y
   };
 
-  if (path.matrix) {
-    pt = transformPoint(out.x, out.y, path.imatrix);
+  if (pth.matrix) {
+    pt = transformPoint(out.x, out.y, pth.imatrix);
     out.x = pt.x;
     out.y = pt.y;
   }
@@ -400,8 +402,8 @@ export const addPointGrip = function (index, x, y) {
 export const getGripContainer = function () {
   let c = getElem('pathpointgrip_container');
   if (!c) {
-    const parent = getElem('selectorParentGroup');
-    c = parent.appendChild(document.createElementNS(NS.SVG, 'g'));
+    const parentElement = getElem('selectorParentGroup');
+    c = parentElement.appendChild(document.createElementNS(NS.SVG, 'g'));
     c.id = 'pathpointgrip_container';
   }
   return c;
@@ -539,7 +541,7 @@ export const replacePathSeg = function (type, index, pts, elem) {
   const pth = elem || path.elem;
 
   const func = 'createSVGPathSeg' + pathFuncs[type];
-  const seg = pth[func].apply(pth, pts);
+  const seg = pth[func](...pts);
 
   if (supportsPathReplaceItem()) {
     pth.pathSegList.replaceItem(seg, index);
@@ -600,9 +602,9 @@ export const getSegSelector = function (seg, update) {
 
     const pts = ptObjToArr(seg.type, seg.item); // , true);
     for (let i = 0; i < pts.length; i += 2) {
-      const pt = getGripPt(seg, {x: pts[i], y: pts[i + 1]});
-      pts[i] = pt.x;
-      pts[i + 1] = pt.y;
+      const point = getGripPt(seg, {x: pts[i], y: pts[i + 1]});
+      pts[i] = point.x;
+      pts[i + 1] = point.y;
     }
 
     replacePathSeg(seg.type, 1, pts, segLine);
@@ -691,7 +693,7 @@ export class Segment {
    */
   showCtrlPts (y) {
     for (const i in this.ctrlpts) {
-      if (this.ctrlpts.hasOwnProperty(i)) {
+      if ({}.hasOwnProperty.call(this.ctrlpts, i)) {
         this.ctrlpts[i].setAttribute('display', y ? 'inline' : 'none');
       }
     }
@@ -777,7 +779,8 @@ export class Segment {
     const {item} = this;
 
     const curPts = this.ctrlpts
-      ? [item.x += dx, item.y += dy,
+      ? [
+        item.x += dx, item.y += dy,
         item.x1, item.y1, item.x2 += dx, item.y2 += dy
       ]
       : [item.x += dx, item.y += dy];
@@ -786,16 +789,18 @@ export class Segment {
 
     if (this.next && this.next.ctrlpts) {
       const next = this.next.item;
-      const nextPts = [next.x, next.y,
-        next.x1 += dx, next.y1 += dy, next.x2, next.y2];
+      const nextPts = [
+        next.x, next.y,
+        next.x1 += dx, next.y1 += dy, next.x2, next.y2
+      ];
       replacePathSeg(this.next.type, this.next.index, nextPts);
     }
 
     if (this.mate) {
       // The last point of a closed subpath has a 'mate',
       // which is the 'M' segment of the subpath
-      const {item} = this.mate;
-      const pts = [item.x += dx, item.y += dy];
+      const {item: itm} = this.mate;
+      const pts = [itm.x += dx, itm.y += dy];
       replacePathSeg(this.mate.type, this.mate.index, pts);
       // Has no grip, so does not need 'updating'?
     }
@@ -826,9 +831,11 @@ export class Segment {
     item['x' + anum] = pt.x + (pt.x - this.item['x' + num]);
     item['y' + anum] = pt.y + (pt.y - this.item['y' + num]);
 
-    const pts = [item.x, item.y,
+    const pts = [
+      item.x, item.y,
       item.x1, item.y1,
-      item.x2, item.y2];
+      item.x2, item.y2
+    ];
 
     replacePathSeg(seg.type, seg.index, pts);
     seg.update(true);
@@ -845,8 +852,10 @@ export class Segment {
     item['x' + num] += dx;
     item['y' + num] += dy;
 
-    const pts = [item.x, item.y,
-      item.x1, item.y1, item.x2, item.y2];
+    const pts = [
+      item.x, item.y,
+      item.x1, item.y1, item.x2, item.y2
+    ];
 
     replacePathSeg(this.type, this.index, pts);
     this.update(true);
@@ -883,7 +892,7 @@ export class Path {
     this.elem = elem;
     this.segs = [];
     this.selected_pts = [];
-    path = this;
+    path = this; // eslint-disable-line consistent-this
 
     this.init();
   }
@@ -941,7 +950,7 @@ export class Path {
         seg.next.prev = seg;
         seg.mate = segs[startI];
         seg.addGrip();
-        if (this.first_seg == null) {
+        if (isNullish(this.first_seg)) {
           this.first_seg = seg;
         }
       } else if (!nextSeg) {
@@ -977,7 +986,7 @@ export class Path {
   * @callback module:path.PathEachSegCallback
   * @this module:path.Segment
   * @param {Integer} i The index of the seg being iterated
-  * @returns {boolean} Will stop execution of `eachSeg` if returns `false`
+  * @returns {boolean|undefined} Will stop execution of `eachSeg` if returns `false`
   */
   /**
   * @param {module:path.PathEachSegCallback} fn
@@ -1062,29 +1071,6 @@ export class Path {
     }
   }
 
-  /**
-  * @param {Integer} index
-  * @returns {boolean}
-  */
-  subpathIsClosed (index) {
-    let closed = false;
-    // Check if subpath is already open
-    path.eachSeg(function (i) {
-      if (i <= index) { return true; }
-      if (this.type === 2) {
-        // Found M first, so open
-        return false;
-      }
-      if (this.type === 1) {
-        // Found Z first, so closed
-        closed = true;
-        return false;
-      }
-    });
-
-    return closed;
-  }
-
   /**
   * @param {Integer} index
   * @returns {undefined}
@@ -1235,7 +1221,7 @@ export class Path {
   */
   selectPt (pt, ctrlNum) {
     this.clearSelection();
-    if (pt == null) {
+    if (isNullish(pt)) {
       this.eachSeg(function (i) {
         // 'this' is the segment here.
         if (this.prev) {
@@ -1312,11 +1298,35 @@ export class Path {
       grips[i] = seg.ptgrip;
     }
 
-    const closedSubpath = this.subpathIsClosed(this.selected_pts[0]);
+    const closedSubpath = Path.subpathIsClosed(this.selected_pts[0]);
     editorContext_.addPtsToSelection({grips, closedSubpath});
   }
 }
 
+/**
+* @param {Integer} index
+* @returns {boolean}
+*/
+Path.subpathIsClosed = function (index) {
+  let clsd = false;
+  // Check if subpath is already open
+  path.eachSeg(function (i) {
+    if (i <= index) { return true; }
+    if (this.type === 2) {
+      // Found M first, so open
+      return false;
+    }
+    if (this.type === 1) {
+      // Found Z first, so closed
+      clsd = true;
+      return false;
+    }
+    return true;
+  });
+
+  return clsd;
+};
+
 /**
 * @function module:path.getPath_
 * @param {SVGPathElement} elem
@@ -1408,7 +1418,7 @@ export const recalcRotatedPath = function () {
 
     const rvals = getRotVals(seg.x, seg.y),
       points = [rvals.x, rvals.y];
-    if (seg.x1 != null && seg.x2 != null) {
+    if (!isNullish(seg.x1) && !isNullish(seg.x2)) {
       const cVals1 = getRotVals(seg.x1, seg.y1);
       const cVals2 = getRotVals(seg.x2, seg.y2);
       points.splice(points.length, 0, cVals1.x, cVals1.y, cVals2.x, cVals2.y);
@@ -1492,26 +1502,28 @@ export const reorientGrads = function (elem, m) {
 * @name module:path.pathMap
 * @type {GenericArray}
 */
-const pathMap = [0, 'z', 'M', 'm', 'L', 'l', 'C', 'c', 'Q', 'q', 'A', 'a',
-  'H', 'h', 'V', 'v', 'S', 's', 'T', 't'];
+const pathMap = [
+  0, 'z', 'M', 'm', 'L', 'l', 'C', 'c', 'Q', 'q', 'A', 'a',
+  'H', 'h', 'V', 'v', 'S', 's', 'T', 't'
+];
 
 /**
  * Convert a path to one with only absolute or relative values.
  * @todo move to pathActions.js
  * @function module:path.convertPath
- * @param {SVGPathElement} path - the path to convert
+ * @param {SVGPathElement} pth - the path to convert
  * @param {boolean} toRel - true of convert to relative
  * @returns {string}
  */
-export const convertPath = function (path, toRel) {
-  const segList = path.pathSegList;
-  const len = segList.numberOfItems;
+export const convertPath = function (pth, toRel) {
+  const {pathSegList} = pth;
+  const len = pathSegList.numberOfItems;
   let curx = 0, cury = 0;
   let d = '';
   let lastM = null;
 
   for (let i = 0; i < len; ++i) {
-    const seg = segList.getItem(i);
+    const seg = pathSegList.getItem(i);
     // if these properties are not in the segment, set them to zero
     let x = seg.x || 0,
       y = seg.y || 0,
@@ -1776,7 +1788,7 @@ export const pathActions = (function () {
     * @param {Element} mouseTarget
     * @param {Float} startX
     * @param {Float} startY
-    * @returns {undefined}
+    * @returns {boolean|undefined}
     */
     mouseDown (evt, mouseTarget, startX, startY) {
       let id;
@@ -1922,7 +1934,7 @@ export const pathActions = (function () {
               editorContext_.getMouseTarget(evt)
             )) {
               // Clicked outside canvas, so don't make point
-              console.log('Clicked outside canvas');
+              // console.log('Clicked outside canvas');
               return false;
             }
 
@@ -1967,11 +1979,11 @@ export const pathActions = (function () {
           // keep = true;
         }
 
-        return;
+        return undefined;
       }
 
       // TODO: Make sure currentPath isn't null at this point
-      if (!path) { return; }
+      if (!path) { return undefined; }
 
       path.storeD();
 
@@ -1979,7 +1991,7 @@ export const pathActions = (function () {
       let curPt;
       if (id.substr(0, 14) === 'pathpointgrip_') {
         // Select this point
-        curPt = path.cur_pt = parseInt(id.substr(14), 10);
+        curPt = path.cur_pt = parseInt(id.substr(14));
         path.dragging = [startX, startY];
         const seg = path.segs[curPt];
 
@@ -2007,7 +2019,7 @@ export const pathActions = (function () {
       // Start selection box
       if (!path.dragging) {
         let rubberBox = editorContext_.getRubberBox();
-        if (rubberBox == null) {
+        if (isNullish(rubberBox)) {
           rubberBox = editorContext_.setRubberBox(
             editorContext_.selectorManager.getRubberBandBox()
           );
@@ -2021,6 +2033,7 @@ export const pathActions = (function () {
           display: 'inline'
         }, 100);
       }
+      return undefined;
     },
     /**
     * @param {Float} mouseX
@@ -2127,7 +2140,7 @@ export const pathActions = (function () {
       } else {
         path.selected_pts = [];
         path.eachSeg(function (i) {
-          const seg = this;
+          const seg = this; // eslint-disable-line consistent-this
           if (!seg.next && !seg.prev) { return; }
 
           // const {item} = seg;
@@ -2150,12 +2163,18 @@ export const pathActions = (function () {
         });
       }
     },
+    /**
+     * @typedef module:path.keepElement
+     * @type {PlainObject}
+     * @property {boolean} keep
+     * @property {Element} element
+     */
     /**
     * @param {Event} evt
     * @param {Element} element
     * @param {Float} mouseX
     * @param {Float} mouseY
-    * @returns {undefined}
+    * @returns {module:path.keepElement|undefined}
     */
     mouseUp (evt, element, mouseX, mouseY) {
       const drawnPath = editorContext_.getDrawnPath();
@@ -2203,6 +2222,7 @@ export const pathActions = (function () {
         pathActions.toSelectMode(evt.target);
       }
       hasMoved = false;
+      return undefined;
     },
     /**
     * @param {Element} element
@@ -2273,8 +2293,8 @@ export const pathActions = (function () {
     reorient () {
       const elem = editorContext_.getSelectedElements()[0];
       if (!elem) { return; }
-      const angle = getRotationAngle(elem);
-      if (angle === 0) { return; }
+      const angl = getRotationAngle(elem);
+      if (angl === 0) { return; }
 
       const batchCmd = new BatchCommand('Reorient path');
       const changes = {
@@ -2321,7 +2341,7 @@ export const pathActions = (function () {
     * @returns {false|undefined}
     */
     resetOrientation (pth) {
-      if (pth == null || pth.nodeName !== 'path') { return false; }
+      if (isNullish(pth) || pth.nodeName !== 'path') { return false; }
       const tlist = getTransformList(pth);
       const m = transformListToTransform(tlist).matrix;
       tlist.clear();
@@ -2357,6 +2377,7 @@ export const pathActions = (function () {
       }
 
       reorientGrads(pth, m);
+      return undefined;
     },
     /**
     * @returns {undefined}
@@ -2449,9 +2470,10 @@ export const pathActions = (function () {
           openPt = false;
           return false;
         }
+        return true;
       });
 
-      if (openPt == null) {
+      if (isNullish(openPt)) {
         // Single path, so close last seg
         openPt = path.segs.length - 1;
       }
diff --git a/editor/recalculate.js b/editor/recalculate.js
index a4559bf0..52512e21 100644
--- a/editor/recalculate.js
+++ b/editor/recalculate.js
@@ -5,12 +5,12 @@
  * @license MIT
  */
 
-import jqPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
+import jQueryPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
 import {NS} from './namespaces.js';
 import {convertToNum} from './units.js';
 import {isWebkit} from './browser.js';
 import {getTransformList} from './svgtransformlist.js';
-import {getRotationAngle, getHref, getBBox, getRefElem} from './utilities.js';
+import {getRotationAngle, getHref, getBBox, getRefElem, isNullish} from './utilities.js';
 import {BatchCommand, ChangeElementCommand} from './history.js';
 import {remapElement} from './coords.js';
 import {
@@ -18,7 +18,7 @@ import {
   hasMatrixTransform
 } from './math.js';
 
-const $ = jqPluginSVG(jQuery);
+const $ = jQueryPluginSVG(jQuery);
 
 let context_;
 
@@ -75,7 +75,7 @@ export const updateClipPath = function (attr, tx, ty) {
 * @returns {Command} Undo command object with the resulting change
 */
 export const recalculateDimensions = function (selected) {
-  if (selected == null) { return null; }
+  if (isNullish(selected)) { return null; }
 
   // Firefox Issue - 1081
   if (selected.nodeName === 'svg' && navigator.userAgent.includes('Firefox/20')) {
@@ -154,7 +154,8 @@ export const recalculateDimensions = function (selected) {
 
       const m = matrixMultiply(
         tlist.getItem(k - 2).matrix,
-        tlist.getItem(k - 1).matrix);
+        tlist.getItem(k - 1).matrix
+      );
       mt.setMatrix(m);
       tlist.removeItem(k - 2);
       tlist.removeItem(k - 2);
@@ -241,7 +242,7 @@ export const recalculateDimensions = function (selected) {
 
   // if we haven't created an initial array in polygon/polyline/path, then
   // make a copy of initial values and include the transform
-  if (initial == null) {
+  if (isNullish(initial)) {
     initial = $.extend(true, {}, changes);
     $.each(initial, function (attr, val) {
       initial[attr] = convertToNum(attr, val);
@@ -795,15 +796,15 @@ export const recalculateDimensions = function (selected) {
     // translation required to re-center it
     // Therefore, [Tr] = [M_inv][Rnew_inv][Rold][M]
     } else if (operation === 3 && angle) {
-      const m = transformListToTransform(tlist).matrix;
+      const {matrix} = transformListToTransform(tlist);
       const roldt = svgroot.createSVGTransform();
       roldt.setRotate(angle, oldcenter.x, oldcenter.y);
       const rold = roldt.matrix;
       const rnew = svgroot.createSVGTransform();
       rnew.setRotate(angle, newcenter.x, newcenter.y);
       const rnewInv = rnew.matrix.inverse();
-      const mInv = m.inverse();
-      const extrat = matrixMultiply(mInv, rnewInv, rold, m);
+      const mInv = matrix.inverse();
+      const extrat = matrixMultiply(mInv, rnewInv, rold, matrix);
 
       remapElement(selected, changes, extrat);
       if (angle) {
diff --git a/editor/redirect-on-lacking-support.js b/editor/redirect-on-lacking-support.js
index 0a4f981a..e967f094 100644
--- a/editor/redirect-on-lacking-support.js
+++ b/editor/redirect-on-lacking-support.js
@@ -1,4 +1,5 @@
 import {supportsSvg} from './browser.js';
+
 if (!supportsSvg()) {
   window.location = 'browser-not-supported.html';
 }
diff --git a/editor/sanitize.js b/editor/sanitize.js
index 891b663a..d866d779 100644
--- a/editor/sanitize.js
+++ b/editor/sanitize.js
@@ -143,7 +143,7 @@ export const sanitizeSvg = function (node) {
       const attrNsURI = attr.namespaceURI;
       // Check that an attribute with the correct localName in the correct namespace is on
       // our whitelist or is a namespace declaration for one of our allowed namespaces
-      if (!(allowedAttrsNS.hasOwnProperty(attrLocalName) && attrNsURI === allowedAttrsNS[attrLocalName] && attrNsURI !== NS.XMLNS) &&
+      if (!({}.hasOwnProperty.call(allowedAttrsNS, attrLocalName) && attrNsURI === allowedAttrsNS[attrLocalName] && attrNsURI !== NS.XMLNS) &&
         !(attrNsURI === NS.XMLNS && REVERSE_NS[attr.value])) {
         // TODO(codedread): Programmatically add the se: attributes to the NS-aware whitelist.
         // Bypassing the whitelist to allow se: prefixes.
@@ -159,11 +159,12 @@ export const sanitizeSvg = function (node) {
         switch (attrName) {
         case 'transform':
         case 'gradientTransform':
-        case 'patternTransform':
+        case 'patternTransform': {
           const val = attr.value.replace(/(\d)-/g, '$1 -');
           node.setAttribute(attrName, val);
           break;
         }
+        }
       }
 
       // For the style attribute, rewrite it in terms of XML presentational attributes
diff --git a/editor/select.js b/editor/select.js
index 27fe81bc..6014925f 100644
--- a/editor/select.js
+++ b/editor/select.js
@@ -8,7 +8,7 @@
  */
 
 import {isTouch, isWebkit} from './browser.js'; // , isOpera
-import {getRotationAngle, getBBox, getStrokedBBox} from './utilities.js';
+import {getRotationAngle, getBBox, getStrokedBBox, isNullish} from './utilities.js';
 import {transformListToTransform, transformBox, transformPoint} from './math.js';
 import {getTransformList} from './svgtransformlist.js';
 
@@ -88,30 +88,6 @@ export class Selector {
     this.selectorGroup.setAttribute('display', 'inline');
   }
 
-  /**
-  * Updates cursors for corner grips on rotation so arrows point the right way.
-  * @param {Float} angle - Current rotation angle in degrees
-  * @returns {undefined}
-  */
-  updateGripCursors (angle) {
-    let dir;
-    const dirArr = [];
-    let steps = Math.round(angle / 45);
-    if (steps < 0) { steps += 8; }
-    for (dir in selectorManager_.selectorGrips) {
-      dirArr.push(dir);
-    }
-    while (steps > 0) {
-      dirArr.push(dirArr.shift());
-      steps--;
-    }
-    let i = 0;
-    for (dir in selectorManager_.selectorGrips) {
-      selectorManager_.selectorGrips[dir].setAttribute('style', ('cursor:' + dirArr[i] + '-resize'));
-      i++;
-    }
-  }
-
   /**
   * Show the resize grips of this selector.
   * @param {boolean} show - Indicates whether grips should be shown or not
@@ -124,7 +100,7 @@ export class Selector {
     this.hasGrips = show;
     if (elem && show) {
       this.selectorGroup.append(selectorManager_.selectorGripsGroup);
-      this.updateGripCursors(getRotationAngle(elem));
+      Selector.updateGripCursors(getRotationAngle(elem));
     }
   }
 
@@ -245,11 +221,10 @@ export class Selector {
       e: [nbax + nbaw, nbay + (nbah) / 2],
       s: [nbax + (nbaw) / 2, nbay + nbah]
     };
-    for (const dir in this.gripCoords) {
-      const coords = this.gripCoords[dir];
+    Object.entries(this.gripCoords).forEach(([dir, coords]) => {
       selectedGrips[dir].setAttribute('cx', coords[0]);
       selectedGrips[dir].setAttribute('cy', coords[1]);
-    }
+    });
 
     // we want to go 20 pixels in the negative transformed y direction, ignoring scale
     mgr.rotateGripConnector.setAttribute('x1', nbax + (nbaw) / 2);
@@ -262,6 +237,23 @@ export class Selector {
     // }
   }
 }
+/**
+* Updates cursors for corner grips on rotation so arrows point the right way.
+* @param {Float} angle - Current rotation angle in degrees
+* @returns {undefined}
+*/
+Selector.updateGripCursors = function (angle) {
+  const dirArr = Object.keys(selectorManager_.selectorGrips);
+  let steps = Math.round(angle / 45);
+  if (steps < 0) { steps += 8; }
+  while (steps > 0) {
+    dirArr.push(dirArr.shift());
+    steps--;
+  }
+  Object.values(selectorManager_.selectorGrips).forEach((gripElement, i) => {
+    gripElement.setAttribute('style', ('cursor:' + dirArr[i] + '-resize'));
+  });
+};
 
 /**
 * Manage all selector objects (selection boxes).
@@ -326,7 +318,7 @@ export class SelectorManager {
     this.rubberBandBox = null;
 
     // add the corner grips
-    for (const dir in this.selectorGrips) {
+    Object.keys(this.selectorGrips).forEach((dir) => {
       const grip = svgFactory_.createSVGElement({
         element: 'circle',
         attr: {
@@ -346,7 +338,7 @@ export class SelectorManager {
       $.data(grip, 'dir', dir);
       $.data(grip, 'type', 'resize');
       this.selectorGrips[dir] = this.selectorGripsGroup.appendChild(grip);
-    }
+    });
 
     // add rotator elems
     this.rotateGripConnector = this.selectorGripsGroup.appendChild(
@@ -420,7 +412,7 @@ export class SelectorManager {
   * @returns {Selector} The selector based on the given element
   */
   requestSelector (elem, bbox) {
-    if (elem == null) { return null; }
+    if (isNullish(elem)) { return null; }
 
     const N = this.selectors.length;
     // If we've already acquired one for this element, return it.
@@ -450,12 +442,12 @@ export class SelectorManager {
   * @returns {undefined}
   */
   releaseSelector (elem) {
-    if (elem == null) { return; }
+    if (isNullish(elem)) { return; }
     const N = this.selectors.length,
       sel = this.selectorMap[elem.id];
     if (!sel.locked) {
       // TODO(codedread): Ensure this exists in this module.
-      console.log('WARNING! selector was released but was already unlocked');
+      console.log('WARNING! selector was released but was already unlocked'); // eslint-disable-line no-console
     }
     for (let i = 0; i < N; ++i) {
       if (this.selectors[i] && this.selectors[i] === sel) {
diff --git a/editor/spinbtn/jQuery.SpinButton.js b/editor/spinbtn/jQuery.SpinButton.js
index be72d810..7f1e60e7 100644
--- a/editor/spinbtn/jQuery.SpinButton.js
+++ b/editor/spinbtn/jQuery.SpinButton.js
@@ -73,7 +73,7 @@
  * @param {external:jQuery} $ The jQuery object to which to add the plug-in
  * @returns {external:jQuery}
 */
-export default function ($) {
+export default function jQueryPluginSpinButton ($) {
   if (!$.loadingStylesheets) {
     $.loadingStylesheets = [];
   }
diff --git a/editor/svg-editor.js b/editor/svg-editor.js
index 09c2c981..bd001fe8 100644
--- a/editor/svg-editor.js
+++ b/editor/svg-editor.js
@@ -13,14 +13,14 @@ import {importSetGlobalDefault} from './external/dynamic-import-polyfill/importM
 import SvgCanvas from './svgcanvas.js';
 import Layer from './layer.js';
 
-import jqPluginJSHotkeys from './js-hotkeys/jquery.hotkeys.min.js';
-import jqPluginBBQ from './jquerybbq/jquery.bbq.min.js';
-import jqPluginSVGIcons from './svgicons/jQuery.svgIcons.js';
-import jqPluginJGraduate from './jgraduate/jQuery.jGraduate.js';
-import jqPluginSpinBtn from './spinbtn/jQuery.SpinButton.js';
-import jqPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
-import jqPluginContextMenu from './contextmenu/jQuery.contextMenu.js';
-import jqPluginJPicker from './jgraduate/jQuery.jPicker.js';
+import jQueryPluginJSHotkeys from './js-hotkeys/jquery.hotkeys.min.js';
+import jQueryPluginBBQ from './jquerybbq/jquery.bbq.min.js';
+import jQueryPluginSVGIcons from './svgicons/jQuery.svgIcons.js';
+import jQueryPluginJGraduate from './jgraduate/jQuery.jGraduate.js';
+import jQueryPluginSpinButton from './spinbtn/jQuery.SpinButton.js';
+import jQueryPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
+import jQueryPluginContextMenu from './contextmenu/jQuery.contextMenu.js';
+import jQueryPluginJPicker from './jgraduate/jQuery.jPicker.js';
 import {
   readLang, putLocale,
   setStrings,
@@ -46,9 +46,9 @@ import loadStylesheets from './external/load-stylesheets/index-es.js';
 const editor = {};
 
 const $ = [
-  jqPluginJSHotkeys, jqPluginBBQ, jqPluginSVGIcons, jqPluginJGraduate,
-  jqPluginSpinBtn, jqPluginSVG, jqPluginContextMenu, jqPluginJPicker
-].reduce(($, cb) => cb($), jQuery);
+  jQueryPluginJSHotkeys, jQueryPluginBBQ, jQueryPluginSVGIcons, jQueryPluginJGraduate,
+  jQueryPluginSpinButton, jQueryPluginSVG, jQueryPluginContextMenu, jQueryPluginJPicker
+].reduce((jq, func) => func(jq), jQuery);
 
 /*
 if (!$.loadingStylesheets) {
@@ -337,11 +337,16 @@ function getImportLocale ({defaultLang, defaultName}) {
    * @param {string} [localeInfo.lang=defaultLang] Defaults to `defaultLang` of {@link module:SVGEditor~getImportLocale}
    * @returns {Promise} Resolves to {@link module:locale.LocaleStrings}
    */
-  return async function importLocale ({name = defaultName, lang = defaultLang} = {}) {
-    async function importLocale (lang) {
-      const url = `${curConfig.extPath}ext-locale/${name}/${lang}.js`;
+  return async function importLocaleDefaulting ({name = defaultName, lang = defaultLang} = {}) {
+    /**
+     *
+     * @param {string} language
+     * @returns {Promise} Resolves to {@link module:locale.LocaleStrings}
+     */
+    function importLocale (language) {
+      const url = `${curConfig.extPath}ext-locale/${name}/${language}.js`;
       return importSetGlobalDefault(url, {
-        global: `svgEditorExtensionLocale_${name}_${lang}`
+        global: `svgEditorExtensionLocale_${name}_${language}`
       });
     }
     try {
@@ -360,7 +365,7 @@ function getImportLocale ({defaultLang, defaultName}) {
 * Store and retrieve preferences.
 * @param {string} key The preference name to be retrieved or set
 * @param {string} [val] The value. If the value supplied is missing or falsey, no change to the preference will be made.
-* @returns {string} If val is missing or falsey, the value of the previously stored preference will be returned.
+* @returns {string|undefined} If val is missing or falsey, the value of the previously stored preference will be returned.
 * @todo Can we change setting on the jQuery namespace (onto editor) to avoid conflicts?
 * @todo Review whether any remaining existing direct references to
 *  getting `curPrefs` can be changed to use `$.pref()` getting to ensure
@@ -377,7 +382,7 @@ $.pref = function (key, val) {
     * @implements {module:SVGEditor.Prefs}
     */
     editor.curPrefs = curPrefs; // Update exported value
-    return;
+    return undefined;
   }
   return (key in curPrefs) ? curPrefs[key] : defaultPrefs[key];
 };
@@ -428,22 +433,20 @@ editor.loadContentAndPrefs = function () {
   }
 
   // LOAD PREFS
-  for (const key in defaultPrefs) {
-    if (defaultPrefs.hasOwnProperty(key)) { // It's our own config, so we don't need to iterate up the prototype chain
-      const storeKey = 'svg-edit-' + key;
-      if (editor.storage) {
-        const val = editor.storage.getItem(storeKey);
-        if (val) {
-          defaultPrefs[key] = String(val); // Convert to string for FF (.value fails in Webkit)
-        }
-      } else if (window.widget) {
-        defaultPrefs[key] = window.widget.preferenceForKey(storeKey);
-      } else {
-        const result = document.cookie.match(new RegExp('(?:^|;\\s*)' + Utils.regexEscape(encodeURIComponent(storeKey)) + '=([^;]+)'));
-        defaultPrefs[key] = result ? decodeURIComponent(result[1]) : '';
+  Object.keys(defaultPrefs).forEach((key) => {
+    const storeKey = 'svg-edit-' + key;
+    if (editor.storage) {
+      const val = editor.storage.getItem(storeKey);
+      if (val) {
+        defaultPrefs[key] = String(val); // Convert to string for FF (.value fails in Webkit)
       }
+    } else if (window.widget) {
+      defaultPrefs[key] = window.widget.preferenceForKey(storeKey);
+    } else {
+      const result = document.cookie.match(new RegExp('(?:^|;\\s*)' + Utils.regexEscape(encodeURIComponent(storeKey)) + '=([^;]+)'));
+      defaultPrefs[key] = result ? decodeURIComponent(result[1]) : '';
     }
-  }
+  });
 };
 
 /**
@@ -476,12 +479,12 @@ editor.setConfig = function (opts, cfgCfg) {
     }
   }
   $.each(opts, function (key, val) {
-    if (opts.hasOwnProperty(key)) {
+    if ({}.hasOwnProperty.call(opts, key)) {
       // Only allow prefs defined in defaultPrefs
-      if (defaultPrefs.hasOwnProperty(key)) {
+      if ({}.hasOwnProperty.call(defaultPrefs, key)) {
         if (cfgCfg.overwrite === false && (
           curConfig.preventAllURLConfig ||
-          curPrefs.hasOwnProperty(key)
+          {}.hasOwnProperty.call(curPrefs, key)
         )) {
           return;
         }
@@ -502,30 +505,26 @@ editor.setConfig = function (opts, cfgCfg) {
         }
         curConfig[key] = curConfig[key].concat(val); // We will handle any dupes later
       // Only allow other curConfig if defined in defaultConfig
-      } else if (defaultConfig.hasOwnProperty(key)) {
+      } else if ({}.hasOwnProperty.call(defaultConfig, key)) {
         if (cfgCfg.overwrite === false && (
           curConfig.preventAllURLConfig ||
-          curConfig.hasOwnProperty(key)
+          {}.hasOwnProperty.call(curConfig, key)
         )) {
           return;
         }
         // Potentially overwriting of previously set config
-        if (curConfig.hasOwnProperty(key)) {
+        if ({}.hasOwnProperty.call(curConfig, key)) {
           if (cfgCfg.overwrite === false) {
             return;
           }
           extendOrAdd(curConfig, key, val);
+        } else if (cfgCfg.allowInitialUserOverride === true) {
+          extendOrAdd(defaultConfig, key, val);
+        } else if (defaultConfig[key] && typeof defaultConfig[key] === 'object') {
+          curConfig[key] = {};
+          $.extend(true, curConfig[key], val); // Merge properties recursively, e.g., on initFill, initStroke objects
         } else {
-          if (cfgCfg.allowInitialUserOverride === true) {
-            extendOrAdd(defaultConfig, key, val);
-          } else {
-            if (defaultConfig[key] && typeof defaultConfig[key] === 'object') {
-              curConfig[key] = {};
-              $.extend(true, curConfig[key], val); // Merge properties recursively, e.g., on initFill, initStroke objects
-            } else {
-              curConfig[key] = val;
-            }
-          }
+          curConfig[key] = val;
         }
       }
     }
@@ -781,7 +780,7 @@ editor.init = function () {
         curConfig.extensions.map(async (extname) => {
           const extName = extname.match(/^ext-(.+)\.js/);
           if (!extName) { // Ensure URL cannot specify some other unintended file in the extPath
-            return;
+            return undefined;
           }
           const url = curConfig.extPath + extname;
           // Todo: Replace this with `return import(url);` when
@@ -803,12 +802,15 @@ editor.init = function () {
             const importLocale = getImportLocale({defaultLang: langParam, defaultName: name});
             return editor.addExtension(name, (init && init.bind(editor)), importLocale);
           } catch (err) {
-            console.log(err);
-            console.error('Extension failed to load: ' + extname + '; ' + err);
+            // Todo: Add config to alert any errors
+            console.log(err); // eslint-disable-line no-console
+            console.error('Extension failed to load: ' + extname + '; ' + err); // eslint-disable-line no-console
+            return undefined;
           }
         })
       );
-      svgCanvas.bind('extensions_added',
+      svgCanvas.bind(
+        'extensions_added',
         /**
         * @param {external:Window} win
         * @param {module:svgcanvas.SvgCanvas#event:extensions_added} data
@@ -888,8 +890,8 @@ editor.init = function () {
       for (let i = 0; i < 4; i++) {
         const s = sides[i];
         let cur = el.data('orig_margin-' + s);
-        if (cur == null) {
-          cur = parseInt(el.css('margin-' + s), 10);
+        if (Utils.isNullish(cur)) {
+          cur = parseInt(el.css('margin-' + s));
           // Cache the original margin
           el.data('orig_margin-' + s, cur);
         }
@@ -1336,8 +1338,14 @@ editor.init = function () {
         }
       });
 
-      function getStylesheetPriority (stylesheet) {
-        switch (stylesheet) {
+      /**
+       * Since stylesheets may be added out of order, we indicate the desired order
+       *   for defaults and others after them (in an indeterminate order).
+       * @param {string} stylesheetFile
+       * @returns {Integer|PositiveInfinity}
+       */
+      function getStylesheetPriority (stylesheetFile) {
+        switch (stylesheetFile) {
         case 'jgraduate/css/jPicker.css':
           return 1;
         case 'jgraduate/css/jGraduate.css':
@@ -1366,7 +1374,7 @@ editor.init = function () {
           stylesheets.splice(idx, 1, ...$.loadingStylesheets);
         }
       }
-      loadStylesheets(stylesheets, {acceptErrors: ({stylesheetURL, reject, resolve}) => {
+      loadStylesheets(stylesheets, {acceptErrors ({stylesheetURL, reject, resolve}) {
         if ($.loadingStylesheets.includes(stylesheetURL)) {
           reject(new Error(`Missing expected stylesheet: ${stylesheetURL}`));
           return;
@@ -1387,7 +1395,8 @@ editor.init = function () {
     document.getElementById('svgcanvas'),
     curConfig
   );
-  const palette = [ // Todo: Make into configuration item?
+  const palette = [
+      // Todo: Make into configuration item?
       '#000000', '#3f3f3f', '#7f7f7f', '#bfbfbf', '#ffffff',
       '#ff0000', '#ff7f00', '#ffff00', '#7fff00',
       '#00ff00', '#00ff7f', '#00ffff', '#007fff',
@@ -1487,7 +1496,7 @@ editor.init = function () {
             if (checkbox.tooltip) {
               label.attr('title', checkbox.tooltip);
             }
-            chkbx.prop('checked', !!checkbox.checked);
+            chkbx.prop('checked', Boolean(checkbox.checked));
             div.append($('<div>').append(label));
           }
           $.each(opts || [], function (opt, val) {
@@ -1649,7 +1658,7 @@ editor.init = function () {
 
     editingsource = true;
     origSource = svgCanvas.getSvgString();
-    $('#save_output_btns').toggle(!!forSaving);
+    $('#save_output_btns').toggle(Boolean(forSaving));
     $('#tool_source_back').toggle(!forSaving);
     $('#svg_source_textarea').val(origSource);
     $('#svg_source_editor').fadeIn();
@@ -1931,7 +1940,7 @@ editor.init = function () {
 
       // Create multiple canvases when necessary (due to browser limits)
       if (rulerLen >= limit) {
-        ctxArrNum = parseInt(rulerLen / limit, 10) + 1;
+        ctxArrNum = parseInt(rulerLen / limit) + 1;
         ctxArr = [];
         ctxArr[0] = ctx;
         let copy;
@@ -2078,8 +2087,8 @@ editor.init = function () {
 
     const ratio = newCanX / oldCanX;
 
-    const scrollX = w / 2 - wOrig / 2;
-    const scrollY = h / 2 - hOrig / 2;
+    const scrollX = w / 2 - wOrig / 2; // eslint-disable-line no-shadow
+    const scrollY = h / 2 - hOrig / 2; // eslint-disable-line no-shadow
 
     if (!newCtr) {
       const oldDistX = oldCtr.x - oldCanX;
@@ -2127,39 +2136,35 @@ editor.init = function () {
    * @returns {undefined}
    */
   const updateToolButtonState = function () {
-    let index, button;
     const bNoFill = (svgCanvas.getColor('fill') === 'none');
     const bNoStroke = (svgCanvas.getColor('stroke') === 'none');
     const buttonsNeedingStroke = ['#tool_fhpath', '#tool_line'];
     const buttonsNeedingFillAndStroke = ['#tools_rect .tool_button', '#tools_ellipse .tool_button', '#tool_text', '#tool_path'];
+
     if (bNoStroke) {
-      for (index in buttonsNeedingStroke) {
-        button = buttonsNeedingStroke[index];
-        if ($(button).hasClass('tool_button_current')) {
+      buttonsNeedingStroke.forEach((btn) => {
+        if ($(btn).hasClass('tool_button_current')) {
           clickSelect();
         }
-        $(button).addClass('disabled');
-      }
+        $(btn).addClass('disabled');
+      });
     } else {
-      for (index in buttonsNeedingStroke) {
-        button = buttonsNeedingStroke[index];
-        $(button).removeClass('disabled');
-      }
+      buttonsNeedingStroke.forEach((btn) => {
+        $(btn).removeClass('disabled');
+      });
     }
 
     if (bNoStroke && bNoFill) {
-      for (index in buttonsNeedingFillAndStroke) {
-        button = buttonsNeedingFillAndStroke[index];
-        if ($(button).hasClass('tool_button_current')) {
+      buttonsNeedingFillAndStroke.forEach((btn) => {
+        if ($(btn).hasClass('tool_button_current')) {
           clickSelect();
         }
-        $(button).addClass('disabled');
-      }
+        $(btn).addClass('disabled');
+      });
     } else {
-      for (index in buttonsNeedingFillAndStroke) {
-        button = buttonsNeedingFillAndStroke[index];
-        $(button).removeClass('disabled');
-      }
+      buttonsNeedingFillAndStroke.forEach((btn) => {
+        $(btn).removeClass('disabled');
+      });
     }
 
     svgCanvas.runExtensions('toolButtonStateUpdate', /** @type {module:svgcanvas.SvgCanvas#event:ext-toolButtonStateUpdate} */ {
@@ -2186,14 +2191,14 @@ editor.init = function () {
   // This function also updates the opacity and id elements that are in the context panel
   const updateToolbar = function () {
     let i, len;
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       switch (selectedElement.tagName) {
       case 'use':
       case 'image':
       case 'foreignObject':
         break;
       case 'g':
-      case 'a':
+      case 'a': {
         // Look for common styles
         const childs = selectedElement.getElementsByTagName('*');
         let gWidth = null;
@@ -2213,7 +2218,7 @@ editor.init = function () {
         paintBox.stroke.update(true);
 
         break;
-      default:
+      } default: {
         paintBox.fill.update(true);
         paintBox.stroke.update(true);
 
@@ -2232,10 +2237,11 @@ editor.init = function () {
           setStrokeOpt($('#linecap_' + attr)[0]);
         }
       }
+      }
     }
 
     // All elements including image and group have opacity
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       const opacPerc = (selectedElement.getAttribute('opacity') || 1.0) * 100;
       $('#group_opacity').val(opacPerc);
       $('#opac_slider').slider('option', 'value', opacPerc);
@@ -2250,7 +2256,7 @@ editor.init = function () {
   const updateContextPanel = function () {
     let elem = selectedElement;
     // If element has just been deleted, consider it null
-    if (elem != null && !elem.parentNode) { elem = null; }
+    if (!Utils.isNullish(elem) && !elem.parentNode) { elem = null; }
     const currentLayerName = svgCanvas.getCurrentDrawing().getCurrentLayerName();
     const currentMode = svgCanvas.getMode();
     const unit = curConfig.baseUnit !== 'px' ? curConfig.baseUnit : null;
@@ -2260,7 +2266,7 @@ editor.init = function () {
     $('#selected_panel, #multiselected_panel, #g_panel, #rect_panel, #circle_panel,' +
       '#ellipse_panel, #line_panel, #text_panel, #image_panel, #container_panel,' +
       ' #use_panel, #a_panel').hide();
-    if (elem != null) {
+    if (!Utils.isNullish(elem)) {
       const elname = elem.nodeName;
       // If this is a link with no transform and one child, pretend
       // its child is selected
@@ -2436,7 +2442,7 @@ editor.init = function () {
       }
       menuItems[(tagName === 'g' ? 'en' : 'dis') + 'ableContextMenuItems']('#ungroup');
       menuItems[((tagName === 'g' || !multiselected) ? 'dis' : 'en') + 'ableContextMenuItems']('#group');
-    // if (elem != null)
+    // if (!Utils.isNullish(elem))
     } else if (multiselected) {
       $('#multiselected_panel').show();
       menuItems
@@ -2506,9 +2512,9 @@ editor.init = function () {
     }
     const isNode = mode === 'pathedit';
     // if elems[1] is present, then we have more than one element
-    selectedElement = (elems.length === 1 || elems[1] == null ? elems[0] : null);
-    multiselected = (elems.length >= 2 && elems[1] != null);
-    if (selectedElement != null) {
+    selectedElement = (elems.length === 1 || Utils.isNullish(elems[1]) ? elems[0] : null);
+    multiselected = (elems.length >= 2 && !Utils.isNullish(elems[1]));
+    if (!Utils.isNullish(selectedElement)) {
       // unless we're already in always set the mode of the editor to select because
       // upon creation of a text element the editor is switched into
       // select mode and this event fires - we need our UI to be in sync
@@ -2516,7 +2522,7 @@ editor.init = function () {
       if (!isNode) {
         updateToolbar();
       }
-    } // if (elem != null)
+    } // if (!Utils.isNullish(elem))
 
     // Deal with pathedit mode
     togglePathEditMode(isNode, elems);
@@ -2545,7 +2551,7 @@ editor.init = function () {
       return;
     }
 
-    multiselected = (elems.length >= 2 && elems[1] != null);
+    multiselected = (elems.length >= 2 && !Utils.isNullish(elems[1]));
     // Only updating fields for single elements for now
     if (!multiselected) {
       switch (mode) {
@@ -2601,7 +2607,7 @@ editor.init = function () {
         }
       // Update selectedElement if element is no longer part of the image.
       // This occurs for the text elements in Firefox
-      } else if (elem && selectedElement && selectedElement.parentNode == null) {
+      } else if (elem && selectedElement && Utils.isNullish(selectedElement.parentNode)) {
         // || elem && elem.tagName == "path" && !multiselected) { // This was added in r1430, but not sure why
         selectedElement = elem;
       }
@@ -2820,7 +2826,7 @@ editor.init = function () {
                   options = tool;
                 } else {
                   // If flyout is selected, allow shift key to iterate through subitems
-                  i = parseInt(i, 10);
+                  i = parseInt(i);
                   // Use `allHolders` to include both extension `includeWith` and toolbarButtons
                   options = allHolders[opts.parent][i + 1] ||
                     holders[opts.parent][0];
@@ -3048,7 +3054,7 @@ editor.init = function () {
         let html;
         // TODO: Allow support for other types, or adding to existing tool
         switch (tool.type) {
-        case 'tool_button':
+        case 'tool_button': {
           html = '<div class="tool_button">' + tool.id + '</div>';
           const div = $(html).appendTo(panel);
           if (tool.events) {
@@ -3057,7 +3063,7 @@ editor.init = function () {
             });
           }
           break;
-        case 'select':
+        } case 'select': {
           html = '<label' + contId + '>' +
             '<select id="' + tool.id + '">';
           $.each(tool.options, function (val, text) {
@@ -3072,7 +3078,7 @@ editor.init = function () {
             $(sel).bind(evt, func);
           });
           break;
-        case 'button-select':
+        } case 'button-select': {
           html = '<div id="' + tool.id + '" class="dropdown toolset" title="' + tool.title + '">' +
             '<div id="cur_' + tool.id + '" class="icon_label"></div><button></button></div>';
 
@@ -3094,7 +3100,7 @@ editor.init = function () {
           });
 
           break;
-        case 'input':
+        } case 'input': {
           html = '<label' + contId + '>' +
             '<span id="' + tool.id + '_label">' +
             tool.label + ':</span>' +
@@ -3117,8 +3123,7 @@ editor.init = function () {
             });
           }
           break;
-
-        default:
+        } default:
           break;
         }
       });
@@ -3503,11 +3508,11 @@ editor.init = function () {
 
   const changeRotationAngle = function (ctl) {
     svgCanvas.setRotationAngle(ctl.value);
-    $('#tool_reorient').toggleClass('disabled', parseInt(ctl.value, 10) === 0);
+    $('#tool_reorient').toggleClass('disabled', parseInt(ctl.value) === 0);
   };
 
   const changeOpacity = function (ctl, val) {
-    if (val == null) { val = ctl.value; }
+    if (Utils.isNullish(val)) { val = ctl.value; }
     $('#group_opacity').val(val);
     if (!ctl || !ctl.handle) {
       $('#opac_slider').slider('option', 'value', val);
@@ -3516,7 +3521,7 @@ editor.init = function () {
   };
 
   const changeBlur = function (ctl, val, noUndo) {
-    if (val == null) { val = ctl.value; }
+    if (Utils.isNullish(val)) { val = ctl.value; }
     $('#blur').val(val);
     let complete = false;
     if (!ctl || !ctl.handle) {
@@ -3862,7 +3867,7 @@ editor.init = function () {
 
   editor.addDropDown('#opacity_dropdown', function () {
     if ($(this).find('div').length) { return; }
-    const perc = parseInt($(this).text().split('%')[0], 10);
+    const perc = parseInt($(this).text().split('%')[0]);
     changeOpacity(false, perc);
   }, true);
 
@@ -3947,7 +3952,7 @@ editor.init = function () {
     };
 
     $('#svg_editor').find('button, select, input:not(#text)').focus(function () {
-      inp = this;
+      inp = this; // eslint-disable-line consistent-this
       uiContext = 'toolbars';
       workarea.mousedown(unfocus);
     }).blur(function () {
@@ -4053,19 +4058,19 @@ editor.init = function () {
   // Delete is a contextual tool that only appears in the ribbon if
   // an element has been selected
   const deleteSelected = function () {
-    if (selectedElement != null || multiselected) {
+    if (!Utils.isNullish(selectedElement) || multiselected) {
       svgCanvas.deleteSelectedElements();
     }
   };
 
   const cutSelected = function () {
-    if (selectedElement != null || multiselected) {
+    if (!Utils.isNullish(selectedElement) || multiselected) {
       svgCanvas.cutSelectedElements();
     }
   };
 
   const copySelected = function () {
-    if (selectedElement != null || multiselected) {
+    if (!Utils.isNullish(selectedElement) || multiselected) {
       svgCanvas.copySelectedElements();
     }
   };
@@ -4078,37 +4083,37 @@ editor.init = function () {
   };
 
   const moveToTopSelected = function () {
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       svgCanvas.moveToTopSelectedElement();
     }
   };
 
   const moveToBottomSelected = function () {
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       svgCanvas.moveToBottomSelectedElement();
     }
   };
 
   const moveUpDownSelected = function (dir) {
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       svgCanvas.moveUpDownSelected(dir);
     }
   };
 
   const convertToPath = function () {
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       svgCanvas.convertToPath();
     }
   };
 
   const reorientPath = function () {
-    if (selectedElement != null) {
+    if (!Utils.isNullish(selectedElement)) {
       path.reorient();
     }
   };
 
   const makeHyperlink = function () {
-    if (selectedElement != null || multiselected) {
+    if (!Utils.isNullish(selectedElement) || multiselected) {
       $.prompt(uiStrings.notification.enterNewLinkURL, 'http://', function (url) {
         if (url) { svgCanvas.makeHyperlink(url); }
       });
@@ -4116,7 +4121,7 @@ editor.init = function () {
   };
 
   const moveSelected = function (dx, dy) {
-    if (selectedElement != null || multiselected) {
+    if (!Utils.isNullish(selectedElement) || multiselected) {
       if (curConfig.gridSnapping) {
         // Use grid snap value regardless of zoom level
         const multi = svgCanvas.getZoom() * curConfig.snappingStep;
@@ -4165,7 +4170,7 @@ editor.init = function () {
   };
 
   const rotateSelected = function (cw, step) {
-    if (selectedElement == null || multiselected) { return; }
+    if (Utils.isNullish(selectedElement) || multiselected) { return; }
     if (!cw) { step *= -1; }
     const angle = parseFloat($('#angle').val()) + step;
     svgCanvas.setRotationAngle(angle);
@@ -4263,7 +4268,7 @@ editor.init = function () {
         if (!customExportImage) {
           openExportWindow();
         }
-        const quality = parseInt($('#image-slider').val(), 10) / 100;
+        const quality = parseInt($('#image-slider').val()) / 100;
         /* const results = */ await svgCanvas.rasterExport(imgType, quality, exportWindowName);
       }
     }, function () {
@@ -4289,6 +4294,7 @@ editor.init = function () {
   };
 
   const clickImport = function () {
+    /* */
   };
 
   const clickUndo = function () {
@@ -4710,13 +4716,14 @@ editor.init = function () {
         fillAttr = (paint[ptype] !== 'none') ? '#' + paint[ptype] : paint[ptype];
         break;
       case 'linearGradient':
-      case 'radialGradient':
+      case 'radialGradient': {
         this.grad.remove();
         this.grad = this.defs.appendChild(paint[ptype]);
         const id = this.grad.id = 'gradbox_' + this.type;
         fillAttr = 'url(#' + id + ')';
         break;
       }
+      }
 
       this.rect.setAttribute('fill', fillAttr);
       this.rect.setAttribute('opacity', opac);
@@ -4992,8 +4999,8 @@ editor.init = function () {
     const rulerX = $('#ruler_x');
     $('#sidepanels').width('+=' + delta);
     $('#layerpanel').width('+=' + delta);
-    rulerX.css('right', parseInt(rulerX.css('right'), 10) + delta);
-    workarea.css('right', parseInt(workarea.css('right'), 10) + delta);
+    rulerX.css('right', parseInt(rulerX.css('right')) + delta);
+    workarea.css('right', parseInt(workarea.css('right')) + delta);
     svgCanvas.runExtensions('workareaResized');
   };
 
@@ -5337,10 +5344,10 @@ editor.init = function () {
             } else {
               keyval = opts.key;
             }
-            keyval += '';
+            keyval = String(keyval);
 
             const {fn} = opts;
-            $.each(keyval.split('/'), function (i, key) {
+            $.each(keyval.split('/'), function (j, key) {
               $(document).bind('keydown', key, function (e) {
                 fn();
                 if (pd) {
@@ -5369,7 +5376,9 @@ editor.init = function () {
         // Misc additional actions
 
         // Make 'return' keypress trigger the change event
-        $('.attr_changer, #image_url').bind('keydown', 'return',
+        $('.attr_changer, #image_url').bind(
+          'keydown',
+          'return',
           function (evt) {
             $(this).change();
             evt.preventDefault();
@@ -5459,7 +5468,7 @@ editor.init = function () {
       toggleSidePanel();
     }
 
-    $('#rulers').toggle(!!curConfig.showRulers);
+    $('#rulers').toggle(Boolean(curConfig.showRulers));
 
     if (curConfig.showRulers) {
       $('#show_rulers')[0].checked = true;
@@ -5631,6 +5640,7 @@ editor.init = function () {
       e.returnValue = uiStrings.notification.unsavedChanges; // Firefox needs this when beforeunload set by addEventListener (even though message is not used)
       return uiStrings.notification.unsavedChanges;
     }
+    return true;
   });
 
   /**
@@ -5702,8 +5712,8 @@ editor.init = function () {
         let reader;
         if (file.type.includes('svg')) {
           reader = new FileReader();
-          reader.onloadend = function (e) {
-            const newElement = svgCanvas.importSvgString(e.target.result, true);
+          reader.onloadend = function (ev) {
+            const newElement = svgCanvas.importSvgString(ev.target.result, true);
             svgCanvas.ungroupSelectedElement();
             svgCanvas.ungroupSelectedElement();
             svgCanvas.groupSelectedElements();
@@ -5761,7 +5771,7 @@ editor.init = function () {
     workarea[0].addEventListener('drop', importImage);
 
     const open = $('<input type="file">').click(function () {
-      const f = this;
+      const f = this; // eslint-disable-line consistent-this
       editor.openPrep(function (ok) {
         if (!ok) { return; }
         svgCanvas.clear();
@@ -5976,7 +5986,7 @@ editor.loadFromURL = function (url, opts) {
     $.ajax({
       url,
       dataType: 'text',
-      cache: !!cache,
+      cache: Boolean(cache),
       beforeSend () {
         $.process_cancel(uiStrings.notification.loadingImage);
       },
@@ -6051,7 +6061,7 @@ const messageQueue = [];
  * @fires module:svgcanvas.SvgCanvas#event:message
  * @returns {undefined}
  */
-const messageListener = ({data, origin}) => {
+const messageListener = ({data, origin}) => { // eslint-disable-line no-shadow
   // console.log('data, origin, extensionsAdded', data, origin, extensionsAdded);
   const messageObj = {data, origin};
   if (!extensionsAdded) {
diff --git a/editor/svgcanvas.js b/editor/svgcanvas.js
index bd5a7317..0ea2ba86 100644
--- a/editor/svgcanvas.js
+++ b/editor/svgcanvas.js
@@ -18,7 +18,7 @@
 // Todo: Obtain/adapt latest jsPDF to utilize ES Module for `jsPDF`/avoid global
 
 import './svgpathseg.js';
-import jqPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
+import jQueryPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
 
 import * as draw from './draw.js';
 import * as pathModule from './path.js';
@@ -32,9 +32,10 @@ import {
   getBBoxOfElementAsPath, convertToPath, toXml, encode64, decode64,
   dataURLToObjectURL, createObjectURL,
   getVisibleElements, dropXMLInteralSubset,
-  init as utilsInit, getBBox as utilsGetBBox, getStrokedBBoxDefaultVisible
+  init as utilsInit, getBBox as utilsGetBBox, getStrokedBBoxDefaultVisible,
+  isNullish
 } from './utilities.js';
-import * as history from './history.js';
+import * as hstry from './history.js';
 import {
   transformPoint, matrixMultiply, hasMatrixTransform, transformListToTransform,
   getMatrix, snapToAngle, isIdentity, rectsIntersect, transformBox
@@ -60,24 +61,25 @@ import {
 } from './recalculate.js';
 import {
   getSelectorManager,
+  Selector,
   init as selectInit
 } from './select.js';
 
-const $ = jqPluginSVG(jQuery);
+const $ = jQueryPluginSVG(jQuery);
 const {
   MoveElementCommand, InsertElementCommand, RemoveElementCommand,
   ChangeElementCommand, BatchCommand, UndoManager, HistoryEventTypes
-} = history;
+} = hstry;
 
 if (!window.console) {
   window.console = {};
-  window.console.log = function (str) {};
-  window.console.dir = function (str) {};
+  window.console.log = function (str) { /* */ };
+  window.console.dir = function (str) { /* */ };
 }
 
 if (window.opera) {
   window.console.log = function (str) { window.opera.postError(str); };
-  window.console.dir = function (str) {};
+  window.console.dir = function (str) { /* */ };
 }
 
 /**
@@ -131,7 +133,7 @@ if (config) {
 // Array with width/height of canvas
 const {dimensions} = curConfig;
 
-const canvas = this;
+const canvas = this; // eslint-disable-line consistent-this
 
 // "document" element associated with the container (same as window.document using default svg-editor.js)
 // NOTE: This is not actually a SVG document, but an HTML document.
@@ -396,7 +398,7 @@ const getSelectedElements = this.getSelectedElems = function () {
   return selectedElements;
 };
 
-const pathActions = pathModule.pathActions;
+const {pathActions} = pathModule;
 
 /**
 * This should actually be an intersection as all interfaces should be met.
@@ -503,8 +505,8 @@ const undoMgr = canvas.undoMgr = new UndoManager({
         }
         if (cmdType === InsertElementCommand.type()) {
           if (isApply) { restoreRefElems(cmd.elem); }
-        } else {
-          if (!isApply) { restoreRefElems(cmd.elem); }
+        } else if (!isApply) {
+          restoreRefElems(cmd.elem);
         }
         if (cmd.elem.tagName === 'use') {
           setUseData(cmd.elem);
@@ -562,7 +564,7 @@ const getCurrentZoom = this.getZoom = function () { return currentZoom; };
 * @implements {module:path.EditorContext#round}
 */
 const round = this.round = function (val) {
-  return parseInt(val * currentZoom, 10) / currentZoom;
+  return parseInt(val * currentZoom) / currentZoom;
 };
 
 selectInit(
@@ -607,12 +609,13 @@ const getId = canvas.getId = function () {
 * @implements {module:draw.DrawCanvasInit#call|module:path.EditorContext#call}
 * @param {"selected"|"changed"|"contextset"|"pointsAdded"|"extension_added"|"extensions_added"|"message"|"transition"|"zoomed"|"updateCanvas"|"zoomDone"|"saved"|"exported"|"exportedPDF"|"setnonce"|"unsetnonce"|"cleared"} ev - String with the event name
 * @param {module:svgcanvas.SvgCanvas#event:GenericCanvasEvent} arg - Argument to pass through to the callback function.
-* @returns {undefined}
+* @returns {module:svgcanvas.EventHandlerReturn|undefined}
 */
 const call = function (ev, arg) {
   if (events[ev]) {
     return events[ev](window, arg);
   }
+  return undefined;
 };
 
 /**
@@ -624,7 +627,7 @@ const call = function (ev, arg) {
 */
 const clearSelection = this.clearSelection = function (noCall) {
   selectedElements.forEach((elem) => {
-    if (elem == null) {
+    if (isNullish(elem)) {
       return;
     }
     selectorManager.releaseSelector(elem);
@@ -646,7 +649,7 @@ const addToSelection = this.addToSelection = function (elemsToAdd, showGrips) {
 
   let j = 0;
   while (j < selectedElements.length) {
-    if (selectedElements[j] == null) {
+    if (isNullish(selectedElements[j])) {
       break;
     }
     ++j;
@@ -692,15 +695,16 @@ const addToSelection = this.addToSelection = function (elemsToAdd, showGrips) {
 
   selectedElements.sort(function (a, b) {
     if (a && b && a.compareDocumentPosition) {
-      return 3 - (b.compareDocumentPosition(a) & 6);
+      return 3 - (b.compareDocumentPosition(a) & 6); // eslint-disable-line no-bitwise
     }
-    if (a == null) {
+    if (isNullish(a)) {
       return 1;
     }
+    return 0;
   });
 
   // Make sure first elements are not null
-  while (selectedElements[0] == null) {
+  while (isNullish(selectedElements[0])) {
     selectedElements.shift(0);
   }
 };
@@ -717,7 +721,7 @@ const getOpacity = function () {
 * @implements {module:path.EditorContext#getMouseTarget}
 */
 const getMouseTarget = this.getMouseTarget = function (evt) {
-  if (evt == null) {
+  if (isNullish(evt)) {
     return null;
   }
   let mouseTarget = evt.target;
@@ -881,8 +885,7 @@ $(opacAni).attr({
 const restoreRefElems = function (elem) {
   // Look for missing reference elements, restore any found
   const attrs = $(elem).attr(refAttrs);
-  for (const o in attrs) {
-    const val = attrs[o];
+  Object.values(attrs).forEach((val) => {
     if (val && val.startsWith('url(')) {
       const id = getUrlFromAttr(val).substr(1);
       const ref = getElem(id);
@@ -891,7 +894,7 @@ const restoreRefElems = function (elem) {
         delete removedElements[id];
       }
     }
-  }
+  });
 
   const childs = elem.getElementsByTagName('*');
 
@@ -1158,9 +1161,9 @@ this.addExtension = async function (name, extInitFunc, importLocale) {
 
     extensions[name] = extObj;
     return call('extension_added', extObj);
-  } else {
-    console.log('Cannot add extension "' + name + '", an extension by that name already exists.');
   }
+  console.log('Cannot add extension "' + name + '", an extension by that name already exists.');
+  return undefined;
 };
 
 /**
@@ -1176,7 +1179,7 @@ this.addExtension = async function (name, extInitFunc, importLocale) {
 * @returns {Element[]|NodeList} Bbox elements
 */
 const getIntersectionList = this.getIntersectionList = function (rect) {
-  if (rubberBox == null) { return null; }
+  if (isNullish(rubberBox)) { return null; }
 
   const parent = currentGroup || getCurrentDrawing().getCurrentLayer();
 
@@ -1201,14 +1204,14 @@ const getIntersectionList = this.getIntersectionList = function (rect) {
   if (!isIE) {
     if (typeof svgroot.getIntersectionList === 'function') {
       // Offset the bbox of the rubber box by the offset of the svgcontent element.
-      rubberBBox.x += parseInt(svgcontent.getAttribute('x'), 10);
-      rubberBBox.y += parseInt(svgcontent.getAttribute('y'), 10);
+      rubberBBox.x += parseInt(svgcontent.getAttribute('x'));
+      rubberBBox.y += parseInt(svgcontent.getAttribute('y'));
 
       resultList = svgroot.getIntersectionList(rubberBBox, parent);
     }
   }
 
-  if (resultList == null || typeof resultList.item !== 'function') {
+  if (isNullish(resultList) || typeof resultList.item !== 'function') {
     resultList = [];
 
     if (!curBBoxes.length) {
@@ -1385,11 +1388,18 @@ canvas.call = call;
  * @type {module:svgcanvas.SvgCanvas#event:selected|module:svgcanvas.SvgCanvas#event:changed|module:svgcanvas.SvgCanvas#event:contextset|module:svgcanvas.SvgCanvas#event:pointsAdded|module:svgcanvas.SvgCanvas#event:extension_added|module:svgcanvas.SvgCanvas#event:extensions_added|module:svgcanvas.SvgCanvas#event:message|module:svgcanvas.SvgCanvas#event:transition|module:svgcanvas.SvgCanvas#event:zoomed|module:svgcanvas.SvgCanvas#event:updateCanvas|module:svgcanvas.SvgCanvas#event:saved|module:svgcanvas.SvgCanvas#event:exported|module:svgcanvas.SvgCanvas#event:exportedPDF|module:svgcanvas.SvgCanvas#event:setnonce|module:svgcanvas.SvgCanvas#event:unsetnonce|undefined}
  */
 
+/**
+ * The promise return, if present, resolves to `undefined`
+ *  (`extension_added`, `exported`, `saved`)
+ * @typedef {Promise|undefined} module:svgcanvas.EventHandlerReturn
+*/
+
 /**
 * @callback module:svgcanvas.EventHandler
 * @param {external:Window} win
 * @param {module:svgcanvas.SvgCanvas#event:GenericCanvasEvent} arg
 * @listens module:svgcanvas.SvgCanvas#event:GenericCanvasEvent
+* @returns {module:svgcanvas.EventHandlerReturn}
 */
 
 /**
@@ -1503,7 +1513,7 @@ this.setRotationAngle = function (val, preventUndo) {
   // }
   const selector = selectorManager.requestSelector(selectedElements[0]);
   selector.resize();
-  selector.updateGripCursors(val);
+  Selector.updateGripCursors(val);
 };
 
 /**
@@ -1574,7 +1584,7 @@ const selectOnly = this.selectOnly = function (elems, showGrips) {
 * @returns {undefined}
 */
 /* const removeFromSelection = */ this.removeFromSelection = function (elemsToRemove) {
-  if (selectedElements[0] == null) { return; }
+  if (isNullish(selectedElements[0])) { return; }
   if (!elemsToRemove.length) { return; }
 
   // find every element and remove it from our array copy
@@ -1732,7 +1742,7 @@ const mouseDown = function (evt) {
   // if it is a selector grip, then it must be a single element selected,
   // set the mouseTarget to that and update the mode to rotate/resize
 
-  if (mouseTarget === selectorManager.selectorParentGroup && selectedElements[0] != null) {
+  if (mouseTarget === selectorManager.selectorParentGroup && !isNullish(selectedElements[0])) {
     const grip = evt.target;
     const griptype = elData(grip, 'type');
     // rotating
@@ -1774,7 +1784,7 @@ const mouseDown = function (evt) {
         // insert a dummy transform so if the element(s) are moved it will have
         // a transform to use for its translate
         for (i = 0; i < selectedElements.length; ++i) {
-          if (selectedElements[i] == null) { continue; }
+          if (isNullish(selectedElements[i])) { continue; }
           const slist = getTransformList(selectedElements[i]);
           if (slist.numberOfItems) {
             slist.insertItemBefore(svgroot.createSVGTransform(), 0);
@@ -1786,7 +1796,7 @@ const mouseDown = function (evt) {
     } else if (!rightClick) {
       clearSelection();
       currentMode = 'multiselect';
-      if (rubberBox == null) {
+      if (isNullish(rubberBox)) {
         rubberBox = selectorManager.getRubberBandBox();
       }
       rStartX *= currentZoom;
@@ -1807,7 +1817,7 @@ const mouseDown = function (evt) {
     break;
   case 'zoom':
     started = true;
-    if (rubberBox == null) {
+    if (isNullish(rubberBox)) {
       rubberBox = selectorManager.getRubberBandBox();
     }
     assignAttributes(rubberBox, {
@@ -1818,7 +1828,7 @@ const mouseDown = function (evt) {
       display: 'inline'
     }, 100);
     break;
-  case 'resize':
+  case 'resize': {
     started = true;
     startX = x;
     startY = y;
@@ -1876,7 +1886,7 @@ const mouseDown = function (evt) {
       }
     }
     break;
-  case 'fhellipse':
+  } case 'fhellipse':
   case 'fhrect':
   case 'fhpath':
     start.x = realX;
@@ -1902,7 +1912,7 @@ const mouseDown = function (evt) {
     freehand.miny = realY;
     freehand.maxy = realY;
     break;
-  case 'image':
+  case 'image': {
     started = true;
     const newImage = addSVGElementFromJson({
       element: 'image',
@@ -1919,7 +1929,7 @@ const mouseDown = function (evt) {
     setHref(newImage, lastGoodImgUrl);
     preventClickDefault(newImage);
     break;
-  case 'square':
+  } case 'square':
     // FIXME: once we create the rect, we lose information that this was a square
     // (for resizing purposes this could be important)
     // Fallthrough
@@ -2119,7 +2129,7 @@ const mouseMove = function (evt) {
         len = selectedElements.length;
         for (i = 0; i < len; ++i) {
           selected = selectedElements[i];
-          if (selected == null) { break; }
+          if (isNullish(selected)) { break; }
           // if (i === 0) {
           //   const box = utilsGetBBox(selected);
           //     selectedBBoxes[i].x = box.x + dx;
@@ -2411,9 +2421,8 @@ const mouseMove = function (evt) {
     start = {x: end.x, y: end.y};
     break;
   // update path stretch line coordinates
-  } case 'path': {
-  }
-  // fall through
+} case 'path': { // eslint-disable-line no-empty
+} // fall through
   case 'pathedit': {
     x *= currentZoom;
     y *= currentZoom;
@@ -2545,16 +2554,16 @@ const mouseUp = function (evt) {
   // intentionally fall-through to select here
   case 'resize':
   case 'multiselect':
-    if (rubberBox != null) {
+    if (!isNullish(rubberBox)) {
       rubberBox.setAttribute('display', 'none');
       curBBoxes = [];
     }
     currentMode = 'select';
     // Fallthrough
   case 'select':
-    if (selectedElements[0] != null) {
+    if (!isNullish(selectedElements[0])) {
       // if we only have one selected element
-      if (selectedElements[1] == null) {
+      if (isNullish(selectedElements[1])) {
         // set our current stroke/fill properties to the element's
         const selected = selectedElements[0];
         switch (selected.tagName) {
@@ -2589,7 +2598,7 @@ const mouseUp = function (evt) {
       if (realX !== rStartX || realY !== rStartY) {
         const len = selectedElements.length;
         for (let i = 0; i < len; ++i) {
-          if (selectedElements[i] == null) { break; }
+          if (isNullish(selectedElements[i])) { break; }
           if (!selectedElements[i].firstChild) {
             // Not needed for groups (incorrectly resizes elems), possibly not needed at all?
             selectorManager.requestSelector(selectedElements[i]).resize();
@@ -2598,7 +2607,7 @@ const mouseUp = function (evt) {
       // no change in position/size, so maybe we should move to pathedit
       } else {
         t = evt.target;
-        if (selectedElements[0].nodeName === 'path' && selectedElements[1] == null) {
+        if (selectedElements[0].nodeName === 'path' && isNullish(selectedElements[1])) {
           pathActions.select(selectedElements[0]);
         // if it was a path
         // else, if it was selected and this is a shift-click, remove it from selection
@@ -2622,7 +2631,7 @@ const mouseUp = function (evt) {
     }
     return;
   case 'zoom':
-    if (rubberBox != null) {
+    if (!isNullish(rubberBox)) {
       rubberBox.setAttribute('display', 'none');
     }
     const factor = evt.shiftKey ? 0.5 : 2;
@@ -2774,7 +2783,7 @@ const mouseUp = function (evt) {
     }
   });
 
-  if (!keep && element != null) {
+  if (!keep && !isNullish(element)) {
     getCurrentDrawing().releaseId(getId());
     element.remove();
     element = null;
@@ -2799,7 +2808,7 @@ const mouseUp = function (evt) {
       canvas.setMode('select');
       selectOnly([t], true);
     }
-  } else if (element != null) {
+  } else if (!isNullish(element)) {
     /**
     * @name module:svgcanvas.SvgCanvas#addedNew
     * @type {boolean}
@@ -2936,8 +2945,8 @@ $(container).bind(
 
     // content offset from canvas in screen pixels
     const wOffset = workarea.offset();
-    const wOffsetLeft = wOffset['left'] + rulerwidth;
-    const wOffsetTop = wOffset['top'] + rulerwidth;
+    const wOffsetLeft = wOffset.left + rulerwidth;
+    const wOffsetTop = wOffset.top + rulerwidth;
 
     const delta = (evt.wheelDelta) ? evt.wheelDelta : (evt.detail) ? -evt.detail : 0;
     if (!delta) { return; }
@@ -3508,7 +3517,7 @@ const removeUnusedDefElems = this.removeUnusedDefElems = function () {
 */
 this.svgCanvasToString = function () {
   // keep calling it until there are none to remove
-  while (removeUnusedDefElems() > 0) {}
+  while (removeUnusedDefElems() > 0) {} // eslint-disable-line no-empty
 
   pathActions.clear(true);
 
@@ -3572,7 +3581,9 @@ this.svgToString = function (elem, indent) {
     const attrs = Array.from(elem.attributes);
     let i;
     const childs = elem.childNodes;
-    attrs.sort((a, b) => a.name > b.name ? -1 : 1);
+    attrs.sort((a, b) => {
+      return a.name > b.name ? -1 : 1;
+    });
 
     for (i = 0; i < indent; i++) { out.push(' '); }
     out.push('<'); out.push(elem.nodeName);
@@ -3693,14 +3704,14 @@ this.svgToString = function (elem, indent) {
           out.push('\n');
           out.push(this.svgToString(childs.item(i), indent));
           break;
-        case 3: // text node
+        case 3: { // text node
           const str = child.nodeValue.replace(/^\s+|\s+$/g, '');
           if (str !== '') {
             bOneLine = true;
             out.push(String(toXml(str)));
           }
           break;
-        case 4: // cdata node
+        } case 4: // cdata node
           out.push('\n');
           out.push(new Array(indent + 1).join(' '));
           out.push('<![CDATA[');
@@ -4308,8 +4319,8 @@ const convertToGroup = this.convertToGroup = function (elem) {
 
     if (vb) {
       const nums = vb.split(' ');
-      pos.x -= +nums[0];
-      pos.y -= +nums[1];
+      pos.x -= Number(nums[0]);
+      pos.y -= Number(nums[1]);
     }
 
     // Not ideal, but works
@@ -4635,12 +4646,12 @@ this.importSvgString = function (xmlString) {
         // if no explicit viewbox, create one out of the width and height
         vb = innervb ? innervb.split(' ') : [0, 0, innerw, innerh];
       for (j = 0; j < 4; ++j) {
-        vb[j] = +(vb[j]);
+        vb[j] = Number(vb[j]);
       }
 
       // TODO: properly handle preserveAspectRatio
       const // canvasw = +svgcontent.getAttribute('width'),
-        canvash = +svgcontent.getAttribute('height');
+        canvash = Number(svgcontent.getAttribute('height'));
       // imported content should be 1/3 of the canvas on its largest dimension
 
       if (innerh > innerw) {
@@ -4864,12 +4875,13 @@ this.setConfig = function (opts) {
 
 /**
 * @function module:svgcanvas.SvgCanvas#getTitle
-* @param {Element} elem
-* @returns {string|undefined} the current group/SVG's title contents
+* @param {Element} [elem]
+* @returns {string|undefined} the current group/SVG's title contents or
+* `undefined` if no element is passed nd there are no selected elements.
 */
 this.getTitle = function (elem) {
   elem = elem || selectedElements[0];
-  if (!elem) { return; }
+  if (!elem) { return undefined; }
   elem = $(elem).data('gsvg') || $(elem).data('symbol') || elem;
   const childs = elem.childNodes;
   for (let i = 0; i < childs.length; i++) {
@@ -5088,24 +5100,29 @@ this.setBBoxZoom = function (val, editorW, editorH) {
   }
 
   switch (val) {
-  case 'selection':
-    if (!selectedElements[0]) { return; }
-    const selectedElems = $.map(selectedElements, function (n) { if (n) { return n; } });
+  case 'selection': {
+    if (!selectedElements[0]) { return undefined; }
+    const selectedElems = $.map(selectedElements, function (n) {
+      if (n) {
+        return n;
+      }
+      return undefined;
+    });
     bb = getStrokedBBoxDefaultVisible(selectedElems);
     break;
-  case 'canvas':
+  } case 'canvas': {
     const res = getResolution();
     spacer = 0.95;
     bb = {width: res.w, height: res.h, x: 0, y: 0};
     break;
-  case 'content':
+  } case 'content':
     bb = getStrokedBBoxDefaultVisible();
     break;
   case 'layer':
     bb = getStrokedBBoxDefaultVisible(getVisibleElements(getCurrentDrawing().getCurrentLayer()));
     break;
   default:
-    return;
+    return undefined;
   }
   return calcZoom(bb);
 };
@@ -5262,14 +5279,12 @@ this.setColor = function (type, val, preventUndo) {
     if (elem) {
       if (elem.tagName === 'g') {
         walkTree(elem, addNonG);
-      } else {
-        if (type === 'fill') {
-          if (elem.tagName !== 'polyline' && elem.tagName !== 'line') {
-            elems.push(elem);
-          }
-        } else {
+      } else if (type === 'fill') {
+        if (elem.tagName !== 'polyline' && elem.tagName !== 'line') {
           elems.push(elem);
         }
+      } else {
+        elems.push(elem);
       }
     }
   }
@@ -5651,14 +5666,12 @@ canvas.setBlurOffsets = function (filter, stdDev) {
       width: '200%',
       height: '200%'
     }, 100);
-  } else {
-    // Removing these attributes hides text in Chrome (see Issue 579)
-    if (!isWebkit()) {
+  // Removing these attributes hides text in Chrome (see Issue 579)
+  } else if (!isWebkit()) {
       filter.removeAttribute('x');
       filter.removeAttribute('y');
       filter.removeAttribute('width');
       filter.removeAttribute('height');
-    }
   }
 };
 
@@ -5739,8 +5752,8 @@ canvas.setBlur = function (val, complete) {
 this.getBold = function () {
   // should only have one element selected
   const selected = selectedElements[0];
-  if (selected != null && selected.tagName === 'text' &&
-    selectedElements[1] == null) {
+  if (!isNullish(selected) && selected.tagName === 'text' &&
+    isNullish(selectedElements[1])) {
     return (selected.getAttribute('font-weight') === 'bold');
   }
   return false;
@@ -5754,8 +5767,8 @@ this.getBold = function () {
 */
 this.setBold = function (b) {
   const selected = selectedElements[0];
-  if (selected != null && selected.tagName === 'text' &&
-    selectedElements[1] == null) {
+  if (!isNullish(selected) && selected.tagName === 'text' &&
+    isNullish(selectedElements[1])) {
     changeSelectedAttribute('font-weight', b ? 'bold' : 'normal');
   }
   if (!selectedElements[0].textContent) {
@@ -5770,8 +5783,8 @@ this.setBold = function (b) {
 */
 this.getItalic = function () {
   const selected = selectedElements[0];
-  if (selected != null && selected.tagName === 'text' &&
-    selectedElements[1] == null) {
+  if (!isNullish(selected) && selected.tagName === 'text' &&
+    isNullish(selectedElements[1])) {
     return (selected.getAttribute('font-style') === 'italic');
   }
   return false;
@@ -5785,8 +5798,8 @@ this.getItalic = function () {
 */
 this.setItalic = function (i) {
   const selected = selectedElements[0];
-  if (selected != null && selected.tagName === 'text' &&
-    selectedElements[1] == null) {
+  if (!isNullish(selected) && selected.tagName === 'text' &&
+    isNullish(selectedElements[1])) {
     changeSelectedAttribute('font-style', i ? 'italic' : 'normal');
   }
   if (!selectedElements[0].textContent) {
@@ -5863,7 +5876,7 @@ this.setFontSize = function (val) {
 */
 this.getText = function () {
   const selected = selectedElements[0];
-  if (selected == null) { return ''; }
+  if (isNullish(selected)) { return ''; }
   return selected.textContent;
 };
 
@@ -5967,7 +5980,7 @@ this.setLinkURL = function (val) {
 */
 this.setRectRadius = function (val) {
   const selected = selectedElements[0];
-  if (selected != null && selected.tagName === 'rect') {
+  if (!isNullish(selected) && selected.tagName === 'rect') {
     const r = selected.getAttribute('rx');
     if (r !== String(val)) {
       selected.setAttribute('rx', val);
@@ -6023,12 +6036,12 @@ this.setSegType = function (newType) {
 * Otherwise the resulting path element is returned.
 */
 this.convertToPath = function (elem, getBBox) {
-  if (elem == null) {
+  if (isNullish(elem)) {
     const elems = selectedElements;
-    $.each(elems, function (i, elem) {
-      if (elem) { canvas.convertToPath(elem); }
+    $.each(elems, function (i, el) {
+      if (el) { canvas.convertToPath(el); }
     });
-    return;
+    return undefined;
   }
   if (getBBox) {
     return getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
@@ -6047,7 +6060,7 @@ this.convertToPath = function (elem, getBBox) {
     opacity: curShape.opacity,
     visibility: 'hidden'
   };
-  return convertToPath(elem, attrs, addSVGElementFromJson, pathActions, clearSelection, addToSelection, history, addCommandToHistory);
+  return convertToPath(elem, attrs, addSVGElementFromJson, pathActions, clearSelection, addToSelection, hstry, addCommandToHistory);
 };
 
 /**
@@ -6066,11 +6079,11 @@ const changeSelectedAttributeNoUndo = function (attr, newValue, elems) {
   elems = elems || selectedElements;
   let i = elems.length;
   const noXYElems = ['g', 'polyline', 'path'];
-  const goodGAttrs = ['transform', 'opacity', 'filter'];
+  // const goodGAttrs = ['transform', 'opacity', 'filter'];
 
   while (i--) {
     let elem = elems[i];
-    if (elem == null) { continue; }
+    if (isNullish(elem)) { continue; }
 
     // Set x,y vals on elements that don't have them
     if ((attr === 'x' || attr === 'y') && noXYElems.includes(elem.tagName)) {
@@ -6082,10 +6095,10 @@ const changeSelectedAttributeNoUndo = function (attr, newValue, elems) {
     }
 
     // only allow the transform/opacity/filter attribute to change on <g> elements, slightly hacky
-    // TODO: FIXME: This doesn't seem right. Where's the body of this if statement?
-    if (elem.tagName === 'g' && goodGAttrs.includes(attr)) {}
+    // TODO: FIXME: Missing statement body
+    // if (elem.tagName === 'g' && goodGAttrs.includes(attr)) {}
     let oldval = attr === '#text' ? elem.textContent : elem.getAttribute(attr);
-    if (oldval == null) { oldval = ''; }
+    if (isNullish(oldval)) { oldval = ''; }
     if (oldval !== String(newValue)) {
       if (attr === '#text') {
         // const oldW = utilsGetBBox(elem).width;
@@ -6209,7 +6222,7 @@ this.deleteSelectedElements = function () {
 
   for (let i = 0; i < len; ++i) {
     const selected = selectedElements[i];
-    if (selected == null) { break; }
+    if (isNullish(selected)) { break; }
 
     let parent = selected.parentNode;
     let t = selected;
@@ -6406,7 +6419,7 @@ this.groupSelectedElements = function (type, urlArg) {
   let i = selectedElements.length;
   while (i--) {
     let elem = selectedElements[i];
-    if (elem == null) { continue; }
+    if (isNullish(elem)) { continue; }
 
     if (elem.parentNode.tagName === 'a' && elem.parentNode.childNodes.length === 1) {
       elem = elem.parentNode;
@@ -6690,7 +6703,7 @@ this.ungroupSelectedElement = function () {
 */
 this.moveToTopSelectedElement = function () {
   const [selected] = selectedElements;
-  if (selected != null) {
+  if (!isNullish(selected)) {
     let t = selected;
     const oldParent = t.parentNode;
     const oldNextSibling = t.nextSibling;
@@ -6713,7 +6726,7 @@ this.moveToTopSelectedElement = function () {
 */
 this.moveToBottomSelectedElement = function () {
   const [selected] = selectedElements;
-  if (selected != null) {
+  if (!isNullish(selected)) {
     let t = selected;
     const oldParent = t.parentNode;
     const oldNextSibling = t.nextSibling;
@@ -6759,9 +6772,9 @@ this.moveUpDownSelected = function (dir) {
       if (this === selected) {
         foundCur = true;
       }
-      return;
+      return true;
     }
-    closest = this;
+    closest = this; // eslint-disable-line consistent-this
     return false;
   });
   if (!closest) { return; }
@@ -6799,7 +6812,7 @@ this.moveSelectedElements = function (dx, dy, undoable) {
   let i = selectedElements.length;
   while (i--) {
     const selected = selectedElements[i];
-    if (selected != null) {
+    if (!isNullish(selected)) {
       // if (i === 0) {
       //   selectedBBoxes[0] = utilsGetBBox(selected);
       // }
@@ -6867,7 +6880,7 @@ this.cloneSelectedElements = function (x, y) {
   selectedElements.sort(sortfunction);
   for (i = 0; i < len; ++i) {
     elem = selectedElements[i];
-    if (elem == null) { break; }
+    if (isNullish(elem)) { break; }
   }
   // use slice to quickly get the subset of elements we need
   const copiedElements = selectedElements.slice(0, i);
@@ -6905,7 +6918,7 @@ this.alignSelectedElements = function (type, relativeTo) {
     miny = Number.MAX_VALUE, maxy = Number.MIN_VALUE;
   let curwidth = Number.MIN_VALUE, curheight = Number.MIN_VALUE;
   for (let i = 0; i < len; ++i) {
-    if (selectedElements[i] == null) { break; }
+    if (isNullish(selectedElements[i])) { break; }
     const elem = selectedElements[i];
     bboxes[i] = getStrokedBBoxDefaultVisible([elem]);
 
@@ -6958,7 +6971,7 @@ this.alignSelectedElements = function (type, relativeTo) {
   const dx = new Array(len);
   const dy = new Array(len);
   for (let i = 0; i < len; ++i) {
-    if (selectedElements[i] == null) { break; }
+    if (isNullish(selectedElements[i])) { break; }
     // const elem = selectedElements[i];
     const bbox = bboxes[i];
     dx[i] = 0;
@@ -7118,7 +7131,7 @@ this.cycleElement = function (next) {
   let elem = false;
   const allElems = getVisibleElements(currentGroup || getCurrentDrawing().getCurrentLayer());
   if (!allElems.length) { return; }
-  if (curElem == null) {
+  if (isNullish(curElem)) {
     num = next ? allElems.length - 1 : 0;
     elem = allElems[num];
   } else {
diff --git a/editor/svgicons/jQuery.svgIcons.js b/editor/svgicons/jQuery.svgIcons.js
index 2a4906e0..546cd602 100644
--- a/editor/svgicons/jQuery.svgIcons.js
+++ b/editor/svgicons/jQuery.svgIcons.js
@@ -1,3 +1,5 @@
+// Todo: Move to own module (and have it import a modular base64 encoder)
+import {encode64} from '../utilities.js';
 /**
  * SVG Icon Loader 2.0
  *
@@ -96,18 +98,22 @@ $(function() {
  * @param {external:jQuery} $ Its keys include all icon IDs and the values, the icon as a jQuery object
  * @returns {external:jQuery} The enhanced jQuery object
 */
-export default function ($) {
+export default function jQueryPluginSVGIcons ($) {
   const svgIcons = {};
 
   let fixIDs;
+  /**
+   * List of raster images with each
+   * key being the SVG icon ID to replace, and the value the image file name
+   * @typedef {PlainObject.<string, string>} external:jQuery.svgIcons.Fallback
+  */
   /**
   * @function external:jQuery.svgIcons
   * @param {string} file The location of a local SVG or SVGz file
   * @param {PlainObject} [opts]
   * @param {Float} [opts.w] The icon widths
   * @param {Float} [opts.h] The icon heights
-  * @param {PlainObject.<string, string>} [opts.fallback] List of raster images with each
-    key being the SVG icon ID to replace, and the value the image file name
+  * @param {external:jQuery.svgIcons.Fallback} [opts.fallback]
   * @param {string} [opts.fallback_path] The path to use for all images
     listed under "fallback"
   * @param {boolean} [opts.replace] If set to `true`, HTML elements will be replaced by,
@@ -132,8 +138,10 @@ export default function ($) {
       iconW = opts.w || 24,
       iconH = opts.h || 24;
     let elems, svgdoc, testImg,
-      iconsMade = false, dataLoaded = false, loadAttempts = 0;
-    const isOpera = !!window.opera,
+      iconsMade = false,
+      dataLoaded = false,
+      loadAttempts = 0;
+    const isOpera = Boolean(window.opera),
       // ua = navigator.userAgent,
       // isSafari = (ua.includes('Safari/') && !ua.includes('Chrome/')),
       dataPre = 'data:image/svg+xml;charset=utf-8;base64,';
@@ -169,24 +177,28 @@ export default function ($) {
             $(function () {
               useFallback();
             });
-          } else {
-            if (err.responseText) {
-              svgdoc = parser.parseFromString(err.responseText, 'text/xml');
+          } else if (err.responseText) {
+            svgdoc = parser.parseFromString(err.responseText, 'text/xml');
 
-              if (!svgdoc.childNodes.length) {
-                $(useFallback);
-              }
-              $(function () {
-                getIcons('ajax');
-              });
-            } else {
+            if (!svgdoc.childNodes.length) {
               $(useFallback);
             }
+            $(function () {
+              getIcons('ajax');
+            });
+          } else {
+            $(useFallback);
           }
         }
       });
     }
 
+    /**
+     *
+     * @param {"ajax"|0|undefined} evt
+     * @param {boolean} [noWait]
+     * @returns {undefined}
+     */
     function getIcons (evt, noWait) {
       if (evt !== 'ajax') {
         if (dataLoaded) return;
@@ -231,6 +243,14 @@ export default function ($) {
       }
     }
 
+    /**
+     *
+     * @param {external:jQuery} target
+     * @param {external:jQuery} icon A wrapped `defs` or Image
+     * @param {string} id SVG icon ID
+     * @param {string} setID
+     * @returns {undefined}
+     */
     function setIcon (target, icon, id, setID) {
       if (isOpera) icon.css('visibility', 'hidden');
       if (opts.replace) {
@@ -249,6 +269,11 @@ export default function ($) {
     }
 
     let holder;
+    /**
+     * @param {external:jQuery} icon A wrapped `defs` or Image
+     * @param {string} id SVG icon ID
+     * @returns {undefined}
+     */
     function addIcon (icon, id) {
       if (opts.id_match === undefined || opts.id_match !== false) {
         setIcon(holder, icon, id, true);
@@ -256,7 +281,13 @@ export default function ($) {
       svgIcons[id] = icon;
     }
 
-    function makeIcons (toImage, fallback) {
+    /**
+     *
+     * @param {boolean} [toImage]
+     * @param {external:jQuery.svgIcons.Fallback} [fallback]
+     * @returns {undefined}
+     */
+    function makeIcons (toImage = false, fallback) {
       if (iconsMade) return;
       if (opts.no_img) toImage = false;
 
@@ -359,13 +390,14 @@ export default function ($) {
       let idElems;
       if (isOpera) {
         idElems = defs.find('*').filter(function () {
-          return !!this.id;
+          return Boolean(this.id);
         });
       } else {
         idElems = defs.find('[id]');
       }
 
-      const allElems = svgEl[0].getElementsByTagName('*'), len = allElems.length;
+      const allElems = svgEl[0].getElementsByTagName('*'),
+        len = allElems.length;
 
       idElems.each(function (i) {
         const {id} = this;
@@ -409,49 +441,20 @@ export default function ($) {
       return svgEl;
     };
 
+    /**
+     * @returns {undefined}
+     */
     function useFallback () {
       if (file.includes('.svgz')) {
         const regFile = file.replace('.svgz', '.svg');
         if (window.console) {
-          console.log('.svgz failed, trying with .svg');
+          console.log('.svgz failed, trying with .svg'); // eslint-disable-line no-console
         }
         $.svgIcons(regFile, opts);
       } else if (opts.fallback) {
         makeIcons(false, opts.fallback);
       }
     }
-
-    function encode64 (input) {
-      // base64 strings are 4/3 larger than the original string
-      if (window.btoa) return window.btoa(input);
-      const _keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
-      const output = new Array(Math.floor((input.length + 2) / 3) * 4);
-
-      let i = 0, p = 0;
-      do {
-        const chr1 = input.charCodeAt(i++);
-        const chr2 = input.charCodeAt(i++);
-        const chr3 = input.charCodeAt(i++);
-
-        const enc1 = chr1 >> 2;
-        const enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
-
-        let enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
-        let enc4 = chr3 & 63;
-        if (isNaN(chr2)) {
-          enc3 = enc4 = 64;
-        } else if (isNaN(chr3)) {
-          enc4 = 64;
-        }
-
-        output[p++] = _keyStr.charAt(enc1);
-        output[p++] = _keyStr.charAt(enc2);
-        output[p++] = _keyStr.charAt(enc3);
-        output[p++] = _keyStr.charAt(enc4);
-      } while (i < input.length);
-
-      return output.join('');
-    }
   };
 
   /**
diff --git a/editor/svgpathseg.js b/editor/svgpathseg.js
index e208fc39..0a26b6d3 100644
--- a/editor/svgpathseg.js
+++ b/editor/svgpathseg.js
@@ -16,6 +16,10 @@
 * including the latest spec changes which were implemented in Firefox 43 and
 * Chrome 46.
 */
+/* eslint-disable no-shadow, class-methods-use-this */
+// Linting: We avoid `no-shadow` as ESLint thinks these are still available globals
+// Linting: We avoid `class-methods-use-this` as this is a polyfill that must
+//   follow the conventions
 (() => {
 if (!('SVGPathSeg' in window)) {
   // Spec: https://www.w3.org/TR/SVG11/single-page.html#paths-InterfaceSVGPathSeg
@@ -591,7 +595,7 @@ if (!('SVGPathSegList' in window) || !('appendItem' in window.SVGPathSegList.pro
         return [];
       }
 
-      const owningPathSegList = this;
+      const owningPathSegList = this; // eslint-disable-line consistent-this
 
       class Builder {
         constructor () {
@@ -883,10 +887,10 @@ if (!('SVGPathSegList' in window) || !('appendItem' in window.SVGPathSegList.pro
           } case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_REL: {
             const points = {x1: this._parseNumber(), y1: this._parseNumber(), x: this._parseNumber(), y: this._parseNumber()};
             return new SVGPathSegCurvetoQuadraticRel(owningPathSegList, points.x, points.y, points.x1, points.y1);
-          } case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_ABS:
+          } case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_ABS: {
             const points = {x1: this._parseNumber(), y1: this._parseNumber(), x: this._parseNumber(), y: this._parseNumber()};
             return new SVGPathSegCurvetoQuadraticAbs(owningPathSegList, points.x, points.y, points.x1, points.y1);
-          case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL:
+          } case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL:
             return new SVGPathSegCurvetoQuadraticSmoothRel(owningPathSegList, this._parseNumber(), this._parseNumber());
           case SVGPathSeg.PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS:
             return new SVGPathSegCurvetoQuadraticSmoothAbs(owningPathSegList, this._parseNumber(), this._parseNumber());
diff --git a/editor/svgtransformlist.js b/editor/svgtransformlist.js
index ed11f714..1b99d0d3 100644
--- a/editor/svgtransformlist.js
+++ b/editor/svgtransformlist.js
@@ -12,7 +12,11 @@ import {supportsNativeTransformLists} from './browser.js';
 
 const svgroot = document.createElementNS(NS.SVG, 'svg');
 
-// Helper function.
+/**
+ * Helper function to convert `SVGTransform` to a string.
+ * @param {SVGTransform} xform
+ * @returns {string}
+ */
 function transformToString (xform) {
   const m = xform.matrix;
   let text = '';
@@ -114,8 +118,9 @@ let listMap_ = {};
 * These methods do not currently raise any exceptions.
 * These methods also do not check that transforms are being inserted.  This is basically
 * implementing as much of SVGTransformList that we need to get the job done.
+* @implements {module:SVGTransformList.SVGEditTransformList}
 */
-export class SVGTransformList {
+export class SVGTransformList {// eslint-disable-line no-shadow
   /**
   * @param {Element} elem
   */
@@ -170,7 +175,7 @@ export class SVGTransformList {
           } else if (name === 'rotate' && values.length === 1) {
             values.push(0, 0);
           }
-          xform[fname].apply(xform, values);
+          xform[fname](...values);
           this._list.appendItem(xform);
         }
       }
@@ -179,20 +184,15 @@ export class SVGTransformList {
       if (item) {
         // Check if this transform is already in a transformlist, and
         // remove it if so.
-        let found = false;
-        for (const id in listMap_) {
-          const tl = listMap_[id];
+        Object.values(listMap_).some((tl) => {
           for (let i = 0, len = tl._xforms.length; i < len; ++i) {
             if (tl._xforms[i] === item) {
-              found = true;
               tl.removeItem(i);
-              break;
+              return true;
             }
           }
-          if (found) {
-            break;
-          }
-        }
+          return false;
+        });
       }
     };
 
@@ -330,7 +330,7 @@ export const resetListMap = function () {
  * @param {Element} elem - a DOM Element
  * @returns {undefined}
  */
-export let removeElementFromListMap = function (elem) {
+export let removeElementFromListMap = function (elem) { // eslint-disable-line import/no-mutable-exports
   if (elem.id && listMap_[elem.id]) {
     delete listMap_[elem.id];
   }
@@ -377,6 +377,7 @@ export const getTransformList = function (elem) {
 * @param {module:SVGTransformList.removeElementFromListMap} cb Passed a single argument `elem`
 * @returns {undefined}
 */
-export const changeRemoveElementFromListMap = function (cb) {
+
+export const changeRemoveElementFromListMap = function (cb) { // eslint-disable-line promise/prefer-await-to-callbacks
   removeElementFromListMap = cb;
 };
diff --git a/editor/touch.js b/editor/touch.js
index f6996b67..256e665d 100644
--- a/editor/touch.js
+++ b/editor/touch.js
@@ -1,4 +1,9 @@
 // http://ross.posterous.com/2008/08/19/iphone-touch-events-in-javascript/
+/**
+ *
+ * @param {Event} ev
+ * @returns {undefined}
+ */
 function touchHandler (ev) {
   const {changedTouches} = ev,
     first = changedTouches[0];
@@ -11,7 +16,7 @@ function touchHandler (ev) {
   default: return;
   }
 
-  const {screenX, screenY, clientX, clientY} = first;
+  const {screenX, screenY, clientX, clientY} = first; // eslint-disable-line no-shadow
   const simulatedEvent = new MouseEvent(type, {
     // Event interface
     bubbles: true,
diff --git a/editor/typedefs.js b/editor/typedefs.js
index 09bdd4b3..7422b42e 100644
--- a/editor/typedefs.js
+++ b/editor/typedefs.js
@@ -50,3 +50,12 @@
 /**
 * @external Window
 */
+
+/**
+ * @external JamilihArray
+ * @type {GenericArray}
+ * @property {string} 0 Element name
+ * @property {PlainObject<string, string>|JamilihArray} [1] Generally a map from an attribute name to attribute value, but also adds event handlers, etc.
+ * @property {JamilihArray} [2] Children
+ * @see {@link https://github.com/brettz9/jamilih/}
+ */
diff --git a/editor/units.js b/editor/units.js
index 13a4e9e0..d5f83416 100644
--- a/editor/units.js
+++ b/editor/units.js
@@ -7,6 +7,7 @@
  */
 
 import {NS} from './namespaces.js';
+import {isNullish} from './utilities.js';
 
 const wAttrs = ['x', 'x1', 'cx', 'rx', 'width'];
 const hAttrs = ['y', 'y1', 'cy', 'ry', 'height'];
@@ -40,7 +41,7 @@ let typeMap_ = {};
  */
 /**
  * @function module:units.ElementContainer#getElement
- * @returns {Element} An element in the container given an id
+ * @returns {?Element} An element in the container given an id
  */
 /**
  * @function module:units.ElementContainer#getHeight
@@ -134,8 +135,7 @@ export const getTypeMap = function () {
 export const shortFloat = function (val) {
   const digits = elementContainer_.getRoundDigits();
   if (!isNaN(val)) {
-    // Note that + converts to Number
-    return +((+val).toFixed(digits));
+    return Number(Number(val).toFixed(digits));
   }
   if (Array.isArray(val)) {
     return shortFloat(val[0]) + ',' + shortFloat(val[1]);
@@ -304,7 +304,7 @@ export const isValidUnit = function (attr, val, selectedElement) {
     // not already present
     try {
       const elem = elementContainer_.getElement(val);
-      result = (elem == null || elem === selectedElement);
+      result = (isNullish(elem) || elem === selectedElement);
     } catch (e) {}
     return result;
   }
diff --git a/editor/utilities.js b/editor/utilities.js
index 8a89a6df..4bfeaa58 100644
--- a/editor/utilities.js
+++ b/editor/utilities.js
@@ -8,7 +8,7 @@
  */
 
 import './svgpathseg.js';
-import jqPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
+import jQueryPluginSVG from './jQuery.attr.js'; // Needed for SVG attribute setting and array form with `attr`
 import {NS} from './namespaces.js';
 import {getTransformList} from './svgtransformlist.js';
 import {setUnitAttr, getTypeMap} from './units.js';
@@ -22,7 +22,7 @@ import {
 } from './browser.js';
 
 // Constants
-const $ = jqPluginSVG(jQuery);
+const $ = jQueryPluginSVG(jQuery);
 
 // String used to encode base64.
 const KEYSTR = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
@@ -123,7 +123,12 @@ export const dropXMLInteralSubset = (str) => {
 export const toXml = function (str) {
   // &apos; is ok in XML, but not HTML
   // &gt; does not normally need escaping, though it can if within a CDATA expression (and preceded by "]]")
-  return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&#x27;'); // Note: `&apos;` is XML only
+  return str
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#x27;'); // Note: `&apos;` is XML only
 };
 
 /**
@@ -133,9 +138,9 @@ export const toXml = function (str) {
 * @param {string} str - The string to be converted
 * @returns {string} The converted string
 */
-export const fromXml = function (str) {
+export function fromXml (str) {
   return $('<p/>').html(str).text();
-};
+}
 
 // This code was written by Tyler Akins and has been placed in the
 // public domain.  It would be nice if you left this header intact.
@@ -150,30 +155,33 @@ export const fromXml = function (str) {
 * @param {string} input
 * @returns {string} Base64 output
 */
-export const encode64 = function (input) {
+export function encode64 (input) {
   // base64 strings are 4/3 larger than the original string
   input = encodeUTF8(input); // convert non-ASCII characters
   // input = convertToXMLReferences(input);
   if (window.btoa) {
     return window.btoa(input); // Use native if available
   }
-  const output = [];
-  output.length = Math.floor((input.length + 2) / 3) * 4;
+  const output = new Array(Math.floor((input.length + 2) / 3) * 4);
 
-  let i = 0, p = 0;
+  let i = 0,
+    p = 0;
   do {
     const chr1 = input.charCodeAt(i++);
     const chr2 = input.charCodeAt(i++);
     const chr3 = input.charCodeAt(i++);
 
+    /* eslint-disable no-bitwise */
     const enc1 = chr1 >> 2;
     const enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
 
     let enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
     let enc4 = chr3 & 63;
+    /* eslint-enable no-bitwise */
 
     if (isNaN(chr2)) {
-      enc3 = enc4 = 64;
+      enc3 = 64;
+      enc4 = 64;
     } else if (isNaN(chr3)) {
       enc4 = 64;
     }
@@ -185,7 +193,7 @@ export const encode64 = function (input) {
   } while (i < input.length);
 
   return output.join('');
-};
+}
 
 /**
 * Converts a string from base64.
@@ -193,7 +201,7 @@ export const encode64 = function (input) {
 * @param {string} input Base64-encoded input
 * @returns {string} Decoded output
 */
-export const decode64 = function (input) {
+export function decode64 (input) {
   if (window.atob) {
     return decodeUTF8(window.atob(input));
   }
@@ -210,30 +218,32 @@ export const decode64 = function (input) {
     const enc3 = KEYSTR.indexOf(input.charAt(i++));
     const enc4 = KEYSTR.indexOf(input.charAt(i++));
 
+    /* eslint-disable no-bitwise */
     const chr1 = (enc1 << 2) | (enc2 >> 4);
     const chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
     const chr3 = ((enc3 & 3) << 6) | enc4;
+    /* eslint-enable no-bitwise */
 
     output += String.fromCharCode(chr1);
 
     if (enc3 !== 64) {
-      output = output + String.fromCharCode(chr2);
+      output += String.fromCharCode(chr2);
     }
     if (enc4 !== 64) {
-      output = output + String.fromCharCode(chr3);
+      output += String.fromCharCode(chr3);
     }
   } while (i < input.length);
   return decodeUTF8(output);
-};
+}
 
 /**
 * @function module:utilities.decodeUTF8
 * @param {string} argString
 * @returns {string}
 */
-export const decodeUTF8 = function (argString) {
+export function decodeUTF8 (argString) {
   return decodeURIComponent(escape(argString));
-};
+}
 
 // codedread:does not seem to work with webkit-based browsers on OSX // Brettz9: please test again as function upgraded
 /**
@@ -255,7 +265,8 @@ export const dataURLToObjectURL = function (dataurl) {
   if (typeof Uint8Array === 'undefined' || typeof Blob === 'undefined' || typeof URL === 'undefined' || !URL.createObjectURL) {
     return '';
   }
-  const arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
+  const arr = dataurl.split(','),
+    mime = arr[0].match(/:(.*?);/)[1],
     bstr = atob(arr[1]);
   let n = bstr.length;
   const u8arr = new Uint8Array(n);
@@ -430,7 +441,7 @@ export const getUrlFromAttr = function (attrVal) {
 * @param {Element} elem
 * @returns {string} The given element's `xlink:href` value
 */
-export let getHref = function (elem) {
+export let getHref = function (elem) { // eslint-disable-line import/no-mutable-exports
   return elem.getAttributeNS(NS.XLINK, 'href');
 };
 
@@ -441,7 +452,7 @@ export let getHref = function (elem) {
 * @param {string} val
 * @returns {undefined}
 */
-export let setHref = function (elem, val) {
+export let setHref = function (elem, val) { // eslint-disable-line import/no-mutable-exports
   elem.setAttributeNS(NS.XLINK, 'xlink:href', val);
 };
 
@@ -484,6 +495,15 @@ export const getPathBBox = function (path) {
   const start = seglist.getItem(0);
   let P0 = [start.x, start.y];
 
+  const getCalc = function (j, P1, P2, P3) {
+    return function (t) {
+      return Math.pow(1 - t, 3) * P0[j] +
+        3 * Math.pow(1 - t, 2) * t * P1[j] +
+        3 * (1 - t) * Math.pow(t, 2) * P2[j] +
+        Math.pow(t, 3) * P3[j];
+    };
+  };
+
   for (let i = 0; i < tot; i++) {
     const seg = seglist.getItem(i);
 
@@ -499,21 +519,14 @@ export const getPathBBox = function (path) {
         P3 = [seg.x, seg.y];
 
       for (let j = 0; j < 2; j++) {
-        const calc = function (t) {
-          return Math.pow(1 - t, 3) * P0[j] +
-            3 * Math.pow(1 - t, 2) * t * P1[j] +
-            3 * (1 - t) * Math.pow(t, 2) * P2[j] +
-            Math.pow(t, 3) * P3[j];
-        };
+        const calc = getCalc(j, P1, P2, P3);
 
         const b = 6 * P0[j] - 12 * P1[j] + 6 * P2[j];
         const a = -3 * P0[j] + 9 * P1[j] - 9 * P2[j] + 3 * P3[j];
         const c = 3 * P1[j] - 3 * P0[j];
 
         if (a === 0) {
-          if (b === 0) {
-            continue;
-          }
+          if (b === 0) { continue; }
           const t = -c / b;
           if (t > 0 && t < 1) {
             bounds[j].push(calc(t));
@@ -612,15 +625,15 @@ export const getBBox = function (elem) {
       selected.textContent = 'a'; // Some character needed for the selector to use.
       ret = selected.getBBox();
       selected.textContent = '';
-    } else {
-      if (selected.getBBox) { ret = selected.getBBox(); }
+    } else if (selected.getBBox) {
+      ret = selected.getBBox();
     }
     break;
   case 'path':
     if (!supportsPathBBox()) {
       ret = getPathBBox(selected);
-    } else {
-      if (selected.getBBox) { ret = selected.getBBox(); }
+    } else if (selected.getBBox) {
+      ret = selected.getBBox();
     }
     break;
   case 'g':
@@ -719,12 +732,13 @@ export const getPathDFromElement = function (elem) {
   let d, a, rx, ry;
   switch (elem.tagName) {
   case 'ellipse':
-  case 'circle':
+  case 'circle': {
     a = $(elem).attr(['rx', 'ry', 'cx', 'cy']);
     const {cx, cy} = a;
     ({rx, ry} = a);
     if (elem.tagName === 'circle') {
-      rx = ry = $(elem).attr('r');
+      ry = $(elem).attr('r');
+      rx = ry;
     }
 
     d = getPathDFromSegments([
@@ -736,7 +750,7 @@ export const getPathDFromElement = function (elem) {
       ['Z', []]
     ]);
     break;
-  case 'path':
+  } case 'path':
     d = elem.getAttribute('d');
     break;
   case 'line':
@@ -749,11 +763,13 @@ export const getPathDFromElement = function (elem) {
   case 'polygon':
     d = 'M' + elem.getAttribute('points') + ' Z';
     break;
-  case 'rect':
+  case 'rect': {
     const r = $(elem).attr(['rx', 'ry']);
     ({rx, ry} = r);
     const b = elem.getBBox();
-    const {x, y} = b, w = b.width, h = b.height;
+    const {x, y} = b,
+      w = b.width,
+      h = b.height;
     num = 4 - num; // Why? Because!
 
     if (!rx && !ry) {
@@ -781,7 +797,7 @@ export const getPathDFromElement = function (elem) {
       ]);
     }
     break;
-  default:
+  } default:
     break;
   }
 
@@ -826,11 +842,11 @@ export const getBBoxOfElementAsPath = function (elem, addSVGElementFromJson, pat
     path.setAttribute('transform', eltrans);
   }
 
-  const parent = elem.parentNode;
+  const {parentNode} = elem;
   if (elem.nextSibling) {
     elem.before(path);
   } else {
-    parent.append(path);
+    parentNode.append(path);
   }
 
   const d = getPathDFromElement(elem);
@@ -861,12 +877,12 @@ export const getBBoxOfElementAsPath = function (elem, addSVGElementFromJson, pat
 * @param {module:path.pathActions} pathActions - If a transform exists, pathActions.resetOrientation() is used. See: canvas.pathActions.
 * @param {module:draw.DrawCanvasInit#clearSelection|module:path.EditorContext#clearSelection} clearSelection - see [canvas.clearSelection]{@link module:svgcanvas.SvgCanvas#clearSelection}
 * @param {module:path.EditorContext#addToSelection} addToSelection - see [canvas.addToSelection]{@link module:svgcanvas.SvgCanvas#addToSelection}
-* @param {module:history} history - see history module
+* @param {module:history} hstry - see history module
 * @param {module:path.EditorContext#addCommandToHistory|module:draw.DrawCanvasInit#addCommandToHistory} addCommandToHistory - see [canvas.addCommandToHistory]{@link module:svgcanvas~addCommandToHistory}
 * @returns {SVGPathElement|null} The converted path element or null if the DOM element was not recognized.
 */
-export const convertToPath = function (elem, attrs, addSVGElementFromJson, pathActions, clearSelection, addToSelection, history, addCommandToHistory) {
-  const batchCmd = new history.BatchCommand('Convert element to Path');
+export const convertToPath = function (elem, attrs, addSVGElementFromJson, pathActions, clearSelection, addToSelection, hstry, addCommandToHistory) {
+  const batchCmd = new hstry.BatchCommand('Convert element to Path');
 
   // Any attribute on the element not covered by the passed-in attributes
   attrs = $.extend({}, attrs, getExtraAttributesForConvertToPath(elem));
@@ -882,11 +898,11 @@ export const convertToPath = function (elem, attrs, addSVGElementFromJson, pathA
   }
 
   const {id} = elem;
-  const parent = elem.parentNode;
+  const {parentNode} = elem;
   if (elem.nextSibling) {
     elem.before(path);
   } else {
-    parent.append(path);
+    parentNode.append(path);
   }
 
   const d = getPathDFromElement(elem);
@@ -939,14 +955,14 @@ export const convertToPath = function (elem, attrs, addSVGElementFromJson, pathA
 * getBBox then apply the angle and any transforms.
 *
 * @param {Float} angle - The rotation angle in degrees
-* @param {boolean} hasMatrixTransform - True if there is a matrix transform
+* @param {boolean} hasAMatrixTransform - True if there is a matrix transform
 * @returns {boolean} True if the bbox can be optimized.
 */
-function bBoxCanBeOptimizedOverNativeGetBBox (angle, hasMatrixTransform) {
+function bBoxCanBeOptimizedOverNativeGetBBox (angle, hasAMatrixTransform) {
   const angleModulo90 = angle % 90;
   const closeTo90 = angleModulo90 < -89.99 || angleModulo90 > 89.99;
   const closeTo0 = angleModulo90 > -0.001 && angleModulo90 < 0.001;
-  return hasMatrixTransform || !(closeTo0 || closeTo90);
+  return hasAMatrixTransform || !(closeTo0 || closeTo90);
 }
 
 /**
@@ -979,13 +995,15 @@ export const getBBoxWithTransform = function (elem, addSVGElementFromJson, pathA
       // TODO: why ellipse and not circle
       const elemNames = ['ellipse', 'path', 'line', 'polyline', 'polygon'];
       if (elemNames.includes(elem.tagName)) {
-        bb = goodBb = getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
+        goodBb = getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
+        bb = goodBb;
       } else if (elem.tagName === 'rect') {
         // Look for radius
         const rx = elem.getAttribute('rx');
         const ry = elem.getAttribute('ry');
         if (rx || ry) {
-          bb = goodBb = getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
+          goodBb = getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
+          bb = goodBb;
         }
       }
     }
@@ -1012,7 +1030,12 @@ export const getBBoxWithTransform = function (elem, addSVGElementFromJson, pathA
   return bb;
 };
 
-// TODO: This is problematic with large stroke-width and, for example, a single horizontal line. The calculated BBox extends way beyond left and right sides.
+/**
+ * @param {Element} elem
+ * @returns {Float}
+ * @todo This is problematic with large stroke-width and, for example, a single
+ * horizontal line. The calculated BBox extends way beyond left and right sides.
+ */
 function getStrokeOffsetForBBox (elem) {
   const sw = elem.getAttribute('stroke-width');
   return (!isNaN(sw) && elem.getAttribute('stroke') !== 'none') ? sw / 2 : 0;
@@ -1090,16 +1113,16 @@ export const getStrokedBBox = function (elems, addSVGElementFromJson, pathAction
 * Note that 0-opacity, off-screen etc elements are still considered "visible"
 * for this function.
 * @function module:utilities.getVisibleElements
-* @param {Element} parent - The parent DOM element to search within
+* @param {Element} parentElement - The parent DOM element to search within
 * @returns {Element[]} All "visible" elements.
 */
-export const getVisibleElements = function (parent) {
-  if (!parent) {
-    parent = $(editorContext_.getSVGContent()).children(); // Prevent layers from being included
+export const getVisibleElements = function (parentElement) {
+  if (!parentElement) {
+    parentElement = $(editorContext_.getSVGContent()).children(); // Prevent layers from being included
   }
 
   const contentElems = [];
-  $(parent).children().each(function (i, elem) {
+  $(parentElement).children().each(function (i, elem) {
     if (elem.getBBox) {
       contentElems.push(elem);
     }
@@ -1148,7 +1171,7 @@ export const getRotationAngleFromTransformList = function (tlist, toRad) {
 * @param {boolean} [toRad=false] - When true returns the value in radians rather than degrees
 * @returns {Float} The angle in degrees or radians
 */
-export let getRotationAngle = function (elem, toRad) {
+export let getRotationAngle = function (elem, toRad) { // eslint-disable-line import/no-mutable-exports
   const selected = elem || editorContext_.getSelectedElements()[0];
   // find the rotation transform (if any) and set it
   const tlist = getTransformList(selected);
@@ -1169,13 +1192,14 @@ export const getRefElem = function (attrVal) {
 * Get a DOM element by ID within the SVG root element.
 * @function module:utilities.getElem
 * @param {string} id - String with the element's new ID
-* @returns {Element}
+* @returns {?Element}
 */
 export const getElem = (supportsSelectors())
   ? function (id) {
     // querySelector lookup
     return svgroot_.querySelector('#' + id);
-  } : supportsXpath()
+  }
+  : supportsXpath()
     ? function (id) {
       // xpath lookup
       return domdoc_.evaluate(
@@ -1183,7 +1207,8 @@ export const getElem = (supportsSelectors())
         domcontainer_,
         function () { return NS.SVG; },
         9,
-        null).singleNodeValue;
+        null
+      ).singleNodeValue;
     }
     : function (id) {
       // jQuery lookup: twice as slow as xpath in FF
@@ -1242,12 +1267,11 @@ export const cleanupElement = function (element) {
     delete defaults.ry;
   }
 
-  for (const attr in defaults) {
-    const val = defaults[attr];
+  Object.entries(defaults).forEach(([attr, val]) => {
     if (element.getAttribute(attr) === String(val)) {
       element.removeAttribute(attr);
     }
-  }
+  });
 };
 
 /**
@@ -1343,6 +1367,15 @@ export const copyElem = function (el, getNextId) {
   return newEl;
 };
 
+/**
+ * Whether a value is `null` or `undefined`.
+ * @param {Any} val
+ * @returns {boolean}
+ */
+export const isNullish = (val) => {
+  return val === null || val === undefined;
+};
+
 /**
 * Overwrite methods for unit testing.
 * @function module:utilities.mock
diff --git a/editor/xdomain-svgedit-config-es.js b/editor/xdomain-svgedit-config-es.js
index daa62815..e8d13a58 100644
--- a/editor/xdomain-svgedit-config-es.js
+++ b/editor/xdomain-svgedit-config-es.js
@@ -1,4 +1,5 @@
 import svgEditor from './svg-editor.js';
+
 svgEditor.setConfig({
   canvasName: 'xdomain', // Namespace this
   allowedOrigins: ['*']
diff --git a/firefox-extension/content/svg-edit-overlay.js b/firefox-extension/content/svg-edit-overlay.js
index 06be3886..ccc7523a 100644
--- a/firefox-extension/content/svg-edit-overlay.js
+++ b/firefox-extension/content/svg-edit-overlay.js
@@ -1,3 +1,7 @@
+/**
+ * Opens the dialog with the SVG Editor.
+ * @returns {undefined}
+ */
 function startSvgEdit () { // eslint-disable-line no-unused-vars
   const url = 'chrome://svg-edit/content/editor/svg-editor.html';
   window.openDialog(url, 'SVG Editor', 'width=1024,height=700,menubar=no,toolbar=no');
diff --git a/firefox-extension/handlers.js b/firefox-extension/handlers.js
index 51d51c69..d33cb0ec 100644
--- a/firefox-extension/handlers.js
+++ b/firefox-extension/handlers.js
@@ -3,6 +3,11 @@
 jQuery(function () {
   if (!window.Components) return;
 
+  /**
+   * Offer choice of file.
+   * @param {boolean} readflag
+   * @returns {nsILocalFile}
+   */
   function mozFilePicker (readflag) {
     const fp = window.Components.classes['@mozilla.org/filepicker;1']
       .createInstance(Components.interfaces.nsIFilePicker);
@@ -19,16 +24,16 @@ jQuery(function () {
         netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
         const file = mozFilePicker(true);
         if (!file) {
-          return null;
+          return;
         }
 
         const inputStream = Components.classes['@mozilla.org/network/file-input-stream;1'].createInstance(Components.interfaces.nsIFileInputStream);
-        inputStream.init(file, 0x01, parseInt('00004', 8), null);
+        inputStream.init(file, 0x01, 0o00004, null);
         const sInputStream = Components.classes['@mozilla.org/scriptableinputstream;1'].createInstance(Components.interfaces.nsIScriptableInputStream);
         sInputStream.init(inputStream);
         svgCanvas.setSvgString(sInputStream.read(sInputStream.available()));
       } catch (e) {
-        console.log('Exception while attempting to load' + e);
+        console.log('Exception while attempting to load' + e); // eslint-disable-line no-console
       }
     },
     save (svg, str) {
@@ -39,16 +44,16 @@ jQuery(function () {
         }
 
         if (!file.exists()) {
-          file.create(0, parseInt('0664', 8));
+          file.create(0, 0o0664);
         }
 
         const out = Components.classes['@mozilla.org/network/file-output-stream;1'].createInstance(Components.interfaces.nsIFileOutputStream);
-        out.init(file, 0x20 | 0x02, parseInt('00004', 8), null);
+        out.init(file, 0x20 | 0x02, 0o00004, null); // eslint-disable-line no-bitwise
         out.write(str, str.length);
         out.flush();
         out.close();
       } catch (e) {
-        alert(e);
+        alert(e); // eslint-disable-line no-alert
       }
     }
   });
diff --git a/jsdoc-check-overly-generic-types.js b/jsdoc-check-overly-generic-types.js
index 02429d1c..8664d894 100644
--- a/jsdoc-check-overly-generic-types.js
+++ b/jsdoc-check-overly-generic-types.js
@@ -3,6 +3,7 @@
  * @todo Fork find-in-files to get ignore pattern support
  */
 const fif = require('find-in-files');
+
 (async () => {
 /**
  * @typedef {PlainObject} FileResult
@@ -15,7 +16,7 @@ const fileMatchPatterns = ['editor'];
  * Keys are file name strings
  * @type {Object.<string, FileResult>}
  */
-let results = await Promise.all(fileMatchPatterns.map(async (fileMatchPattern) => {
+let results = await Promise.all(fileMatchPatterns.map((fileMatchPattern) => {
   return fif.find(
     {
       // We grab to the end of the line as the `line` result for `find-in-files`
@@ -46,22 +47,28 @@ Object.entries(results).forEach(([file, res]) => {
   });
   */
 });
-console.log(`${output}\nTotal failures found: ${total}.\n`);
+console.log(`${output}\nTotal failures found: ${total}.\n`); // eslint-disable-line no-console
 
+/**
+ * @external FindInFilesResult
+ * @type {PlainObject}
+ * @property {string[]} matches The matched strings
+ * @property {Integer} count The number of matches
+ * @property {string[]} line The lines that were matched. The docs mistakenly indicate the property is named `lines`; see {@link https://github.com/kaesetoast/find-in-files/pull/19}.
+ */
+
+/**
+ * Eliminates known false matches against overly generic types.
+ * @param {string} file
+ * @param {external:FindInFilesResult} res
+ * @returns {undefined}
+ */
 function reduceFalseMatches (file, res) {
   switch (file) {
   case 'editor/external/jamilih/jml-es.js':
   case 'editor/xdomain-svgedit-config-iife.js': // Ignore
     res.line = [];
     break;
-  case 'editor/external/dynamic-import-polyfill/importModule.js':
-    res.line = res.line.filter((line) => {
-      return ![
-        '* @returns {*} The return depends on the export of the targeted module.',
-        '* @returns {ArbitraryModule|*} The return depends on the export of the targeted module.'
-      ].includes(line);
-    });
-    break;
   case 'editor/embedapi.js':
     res.line = res.line.filter((line) => {
       return ![
diff --git a/opera-widget/handlers.js b/opera-widget/handlers.js
index 30e391ae..e5d2a549 100644
--- a/opera-widget/handlers.js
+++ b/opera-widget/handlers.js
@@ -1,5 +1,7 @@
 /* globals jQuery, svgCanvas */
-// Note: This JavaScript file must be included as the last script on the main HTML editor page to override the open/save handlers
+/* eslint-disable no-console */
+// Note: This JavaScript file must be included as the last script on the main
+//  HTML editor page to override the open/save handlers
 jQuery(function () {
   if (window.opera && window.opera.io && window.opera.io.filesystem) {
     svgCanvas.setCustomHandlers({
@@ -31,9 +33,9 @@ jQuery(function () {
           console.log('Open file failed.');
         }
       },
-      save (window, svg) {
+      save (win, svg) {
         try {
-          window.opera.io.filesystem.browseForSave(
+          win.opera.io.filesystem.browseForSave(
             new Date().getTime(), /* mountpoint name */
             '', /* default location */
             function (file) {
diff --git a/package-lock.json b/package-lock.json
index 4d880f3c..81f7afaf 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3696,9 +3696,8 @@
       }
     },
     "eslint-plugin-jsdoc": {
-      "version": "3.9.1",
-      "resolved": "https://registry.npmjs.org/eslint-plugin-jsdoc/-/eslint-plugin-jsdoc-3.9.1.tgz",
-      "integrity": "sha512-kSQ62uraDa9QSv/5YncMZoKLScqrq7kt4lGGokH7Iyuqqzo2rZhERdrkPELLdnX4jWwkh+gYFZBt0PVIseKH1g==",
+      "version": "git+https://github.com/brettz9/eslint-plugin-jsdoc.git#11de4556f5c3c357b3a5521640136638a40f7636",
+      "from": "git+https://github.com/brettz9/eslint-plugin-jsdoc.git#ArrayPatternDeploy",
       "dev": true,
       "requires": {
         "comment-parser": "^0.5.0",
diff --git a/package.json b/package.json
index 2fe7522a..37b436b7 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,9 @@
     "example": "examples",
     "test": "test"
   },
-  "engines": {},
+  "engines": {
+    "node": ">= 7.6.0"
+  },
   "scripts": {
     "prepublishOnly": "npm run test-prep",
     "build-config": "rollup -c rollup-config.config.js",
@@ -83,7 +85,7 @@
     "eslint-config-standard": "12.0.0",
     "eslint-plugin-compat": "2.6.3",
     "eslint-plugin-import": "2.14.0",
-    "eslint-plugin-jsdoc": "https://github.com/brettz9/eslint-plugin-jsdoc#origin/ArrayPattern",
+    "eslint-plugin-jsdoc": "https://github.com/brettz9/eslint-plugin-jsdoc#ArrayPatternDeploy",
     "eslint-plugin-markdown": "^1.0.0-rc.0",
     "eslint-plugin-node": "8.0.0",
     "eslint-plugin-promise": "4.0.1",
diff --git a/rollup-config.config.js b/rollup-config.config.js
index 6f2122af..f55374c3 100644
--- a/rollup-config.config.js
+++ b/rollup-config.config.js
@@ -33,6 +33,7 @@ window.svgEditor.modules = false;
   })
 ];
 
+/* eslint-disable import/no-anonymous-default-export */
 export default [
   {
     input: 'svgedit-config-es.js',
diff --git a/rollup.config.js b/rollup.config.js
index 14dc1e7d..83bd267f 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -8,16 +8,17 @@ import babel from 'rollup-plugin-babel';
 import {terser} from 'rollup-plugin-terser';
 import replace from 'rollup-plugin-re';
 
-const {lstatSync, readdirSync} = require('fs');
+const {lstatSync, readdirSync} = require('fs'); // eslint-disable-line import/no-commonjs
+const {join, basename} = require('path'); // eslint-disable-line import/no-commonjs
+
 const localeFiles = readdirSync('editor/locale');
 const extensionFiles = readdirSync('editor/extensions');
-const {join, basename} = require('path');
 
 const isDirectory = (source) => {
   return lstatSync(source).isDirectory();
 };
 const getDirectories = (source) => {
-  return readdirSync(source).map(name => join(source, name)).filter(isDirectory);
+  return readdirSync(source).map((nme) => join(source, nme)).filter(isDirectory);
 };
 const extensionLocaleDirs = getDirectories('editor/extensions/ext-locale');
 const extensionLocaleFiles = [];
@@ -27,6 +28,18 @@ extensionLocaleDirs.forEach((dir) => {
   });
 });
 
+/**
+ * @external RollupConfig
+ * @type {PlainObject}
+ * @see {@link https://rollupjs.org/guide/en#big-list-of-options}
+ */
+
+/**
+ * @param {PlainObject} config
+ * @param {boolean} config.minifying
+ * @param {string} [config.format='umd'} = {}]
+ * @returns {external:RollupConfig}
+ */
 function getRollupObject ({minifying, format = 'umd'} = {}) {
   const nonMinified = {
     input: 'editor/svg-editor.js',
@@ -69,9 +82,7 @@ export default [
         name: `svgEditorExtensionLocale_${basename(dir)}_${lang}`,
         file: `dist/extensions/ext-locale/${basename(dir)}/${file}`
       },
-      plugins: [
-        babel()
-      ]
+      plugins: [babel()]
     };
   }),
   {
@@ -80,9 +91,7 @@ export default [
       format: 'iife',
       file: `dist/redirect-on-lacking-support.js`
     },
-    plugins: [
-      babel()
-    ]
+    plugins: [babel()]
   },
   {
     input: 'editor/jspdf/jspdf.plugin.svgToPdf.js',
@@ -90,9 +99,7 @@ export default [
       format: 'iife',
       file: `dist/jspdf.plugin.svgToPdf.js`
     },
-    plugins: [
-      babel()
-    ]
+    plugins: [babel()]
   },
   {
     input: 'editor/extensions/imagelib/index.js',
@@ -124,9 +131,7 @@ export default [
       format: 'iife',
       file: 'dist/dom-polyfill.js'
     },
-    plugins: [
-      babel()
-    ]
+    plugins: [babel()]
   },
   {
     input: 'editor/canvg/canvg.js',
@@ -135,16 +140,14 @@ export default [
       name: 'canvg',
       file: 'dist/canvg.js'
     },
-    plugins: [
-      babel()
-    ]
+    plugins: [babel()]
   },
   ...localeFiles.map((localeFile) => {
     // lang.*.js
     const localeRegex = /^lang\.([\w-]+?)\.js$/;
     const lang = localeFile.match(localeRegex);
     if (!lang) {
-      return;
+      return undefined;
     }
     return {
       input: 'editor/locale/' + localeFile,
@@ -154,7 +157,8 @@ export default [
         file: 'dist/locale/' + localeFile
       },
       plugins: [
-        babel() // Probably don't need here, but...
+        // Probably don't need here, but...
+        babel()
       ]
     };
   }),
@@ -162,7 +166,7 @@ export default [
     // ext-*.js
     const extensionName = extensionFile.match(/^ext-(.+?)\.js$/);
     if (!extensionName) {
-      return;
+      return undefined;
     }
     return {
       input: 'editor/extensions/' + extensionFile,
@@ -188,10 +192,10 @@ export default [
               // For now, we'll replace with globals
               // We'll still make at least one import: editor/ext-locale/storage/
               `import '../svgpathseg.js';`
-            ].map((test) => {
+            ].map((tst) => {
               return {
                 match: /editor\/extensions/,
-                test,
+                test: tst,
                 replace: ''
               };
             })
diff --git a/screencasts/svgopen2010/script.js b/screencasts/svgopen2010/script.js
index c1ded792..0f20e549 100644
--- a/screencasts/svgopen2010/script.js
+++ b/screencasts/svgopen2010/script.js
@@ -9,9 +9,9 @@ const byId = function (id) {
   return id;
 };
 
-const query = function (query, root) {
-  if (!query) { return []; }
-  if (typeof query !== 'string') { return [...query]; }
+const query = function (qry, root) {
+  if (!qry) { return []; }
+  if (typeof qry !== 'string') { return [...qry]; }
   if (typeof root === 'string') {
     root = byId(root);
     if (!root) { return []; }
@@ -19,17 +19,17 @@ const query = function (query, root) {
 
   root = root || document;
   const rootIsDoc = (root.nodeType === 9);
-  const doc = rootIsDoc ? root : (root.ownerDocument || document);
+  const dcmnt = rootIsDoc ? root : (root.ownerDocument || document);
 
   // rewrite the query to be ID rooted
-  if (!rootIsDoc || ('>~+'.includes(query[0]))) {
+  if (!rootIsDoc || ('>~+'.includes(qry[0]))) {
     root.id = root.id || ('qUnique' + (ctr++));
-    query = '#' + root.id + ' ' + query;
+    qry = '#' + root.id + ' ' + qry;
   }
   // don't choke on something like ".yada.yada >"
-  if ('>~+'.includes(query.slice(-1))) { query += ' *'; }
+  if ('>~+'.includes(qry.slice(-1))) { qry += ' *'; }
 
-  return [...doc.querySelectorAll(query)];
+  return [...dcmnt.querySelectorAll(qry)];
 };
 
 const ua = navigator.userAgent;
@@ -66,9 +66,11 @@ Slide.prototype = {
   _buildList: [],
   _visited: false,
   _currentState: '',
-  _states: [ 'distant-slide', 'far-past',
+  _states: [
+    'distant-slide', 'far-past',
     'past', 'current', 'future',
-    'far-future', 'distant-slide' ],
+    'far-future', 'distant-slide'
+  ],
   setState (state) {
     if (typeof state !== 'string') {
       state = this._states[state];
@@ -85,8 +87,8 @@ Slide.prototype = {
     /*
     this._runAutos();
     */
-    const _t = this;
-    setTimeout(function () { _t._runAutos(); }, 400);
+    const that = this;
+    setTimeout(function () { that._runAutos(); }, 400);
   },
   _makeCounter () {
     if (!this._count || !this._node) { return; }
@@ -121,18 +123,18 @@ Slide.prototype = {
     if (idx >= 0) {
       const elem = this._buildList.splice(idx, 1)[0];
       const transitionEnd = isWK ? 'webkitTransitionEnd' : (isFF ? 'mozTransitionEnd' : 'oTransitionEnd');
-      const _t = this;
+      const that = this;
       if (canTransition()) {
         const l = function (evt) {
           elem.parentNode.removeEventListener(transitionEnd, l);
-          _t._runAutos();
+          that._runAutos();
         };
         elem.parentNode.addEventListener(transitionEnd, l);
         elem.classList.remove('to-build');
       } else {
         setTimeout(function () {
           elem.classList.remove('to-build');
-          _t._runAutos();
+          that._runAutos();
         }, 400);
       }
     }
@@ -156,22 +158,22 @@ const SlideShow = function (slides) {
 
   const h = window.location.hash;
   try {
-    this.current = parseInt(h.split('#slide')[1], 10);
+    this.current = parseInt(h.split('#slide')[1]);
   } catch (e) { /* squeltch */ }
   this.current = isNaN(this.current) ? 1 : this.current;
-  const _t = this;
+  const that = this;
   doc.addEventListener('keydown',
-    function (e) { _t.handleKeys(e); });
+    function (e) { that.handleKeys(e); });
   doc.addEventListener('mousewheel',
-    function (e) { _t.handleWheel(e); });
+    function (e) { that.handleWheel(e); });
   doc.addEventListener('DOMMouseScroll',
-    function (e) { _t.handleWheel(e); });
+    function (e) { that.handleWheel(e); });
   doc.addEventListener('touchstart',
-    function (e) { _t.handleTouchStart(e); });
+    function (e) { that.handleTouchStart(e); });
   doc.addEventListener('touchend',
-    function (e) { _t.handleTouchEnd(e); });
+    function (e) { that.handleTouchEnd(e); });
   window.addEventListener('popstate',
-    function (e) { _t.go(e.state); });
+    function (e) { that.go(e.state); });
   this._update();
 };
 
@@ -242,7 +244,7 @@ SlideShow.prototype = {
     }
   },
   handleKeys (e) {
-    if (/^(input|textarea)$/i.test(e.target.nodeName)) return;
+    if ((/^(input|textarea)$/i).test(e.target.nodeName)) return;
 
     switch (e.keyCode) {
     case 37: // left arrow
@@ -282,15 +284,23 @@ document.querySelector('#toggle-gradients').addEventListener('click', toggleGrad
 const counters = document.querySelectorAll('.counter');
 const slides = document.querySelectorAll('.slide');
 
+/**
+ * Show or hide the counters.
+ * @returns {undefined}
+ */
 function toggleCounter () {
   [...counters].forEach(function (el) {
     el.style.display = (el.offsetHeight) ? 'none' : 'block';
   });
 }
 
+/**
+ * Add or remove `reduced` (size) class.
+ * @returns {undefined}
+ */
 function toggleSize () {
   [...slides].forEach(function (el) {
-    if (!/reduced/.test(el.className)) {
+    if (!(/reduced/).test(el.className)) {
       el.classList.add('reduced');
     } else {
       el.classList.remove('reduced');
@@ -298,9 +308,13 @@ function toggleSize () {
   });
 }
 
+/**
+ * Add or remove `no-transitions` class.
+ * @returns {undefined}
+ */
 function toggleTransitions () {
   [...slides].forEach(function (el) {
-    if (!/no-transitions/.test(el.className)) {
+    if (!(/no-transitions/).test(el.className)) {
       el.classList.add('no-transitions');
     } else {
       el.classList.remove('no-transitions');
@@ -308,9 +322,13 @@ function toggleTransitions () {
   });
 }
 
+/**
+ * Add or remove `no-gradients` class.
+ * @returns {undefined}
+ */
 function toggleGradients () {
   [...slides].forEach(function (el) {
-    if (!/no-gradients/.test(el.className)) {
+    if (!(/no-gradients/).test(el.className)) {
       el.classList.add('no-gradients');
     } else {
       el.classList.remove('no-gradients');
diff --git a/test/contextmenu_test.js b/test/contextmenu_test.js
index c5391536..f2dc36d8 100644
--- a/test/contextmenu_test.js
+++ b/test/contextmenu_test.js
@@ -8,6 +8,10 @@ QUnit.log((details) => {
   }
 });
 
+/**
+ * Tear down tests, resetting custom menus.
+ * @returns {undefined}
+ */
 function tearDown () {
   contextmenu.resetCustomMenus();
 }
@@ -39,7 +43,7 @@ QUnit.test('Test svgedit.contextmenu does not add invalid menu item', function (
 QUnit.test('Test svgedit.contextmenu adds valid menu item', function (assert) {
   assert.expect(2);
 
-  const validItem = {id: 'valid', label: 'anicelabel', action () { alert('testing'); }};
+  const validItem = {id: 'valid', label: 'anicelabel', action () { console.log('testing'); }};
   contextmenu.add(validItem);
 
   assert.ok(contextmenu.hasCustomHandler('valid'), 'Valid menu item is added.');
@@ -50,8 +54,8 @@ QUnit.test('Test svgedit.contextmenu adds valid menu item', function (assert) {
 QUnit.test('Test svgedit.contextmenu rejects valid duplicate menu item id', function (assert) {
   assert.expect(1);
 
-  const validItem1 = {id: 'valid', label: 'anicelabel', action () { alert('testing'); }};
-  const validItem2 = {id: 'valid', label: 'anicelabel', action () { alert('testingtwice'); }};
+  const validItem1 = {id: 'valid', label: 'anicelabel', action () { console.log('testing'); }};
+  const validItem2 = {id: 'valid', label: 'anicelabel', action () { console.log('testingtwice'); }};
   contextmenu.add(validItem1);
   contextmenu.add(validItem2);
 
diff --git a/test/coords_test.js b/test/coords_test.js
index 48837d3d..594a2dd3 100644
--- a/test/coords_test.js
+++ b/test/coords_test.js
@@ -18,6 +18,11 @@ const svg = document.createElementNS(NS.SVG, 'svg');
 svgroot.append(svg);
 
 let elemId = 1;
+
+/**
+ * Set up tests with mock data.
+ * @returns {undefined}
+ */
 function setUp () {
   // Mock out editor context.
   utilities.init(
@@ -38,13 +43,17 @@ function setUp () {
       getGridSnapping () { return false; },
       getDrawing () {
         return {
-          getNextId () { return '' + elemId++; }
+          getNextId () { return String(elemId++); }
         };
       }
     }
   );
 }
 
+/**
+ * Tear down tests, removing elements.
+ * @returns {undefined}
+ */
 function tearDown () {
   while (svg.hasChildNodes()) {
     svg.firstChild.remove();
diff --git a/test/draw_test.js b/test/draw_test.js
index 479041df..6393d198 100644
--- a/test/draw_test.js
+++ b/test/draw_test.js
@@ -65,8 +65,7 @@ const currentDrawing_ = new draw.Drawing(svgcontent, idprefix);
 const getCurrentDrawing = function () {
   return currentDrawing_;
 };
-const setCurrentGroup = (cg) => {
-};
+const setCurrentGroup = (cg) => { /* */ };
 draw.init(
   /**
   * @implements {module:draw.DrawCanvasInit}
@@ -77,11 +76,15 @@ draw.init(
   }
 );
 
+/**
+ * @param {module:utilities.SVGElementJSON} jsonMap
+ * @returns {SVGElement}
+ */
 function createSVGElement (jsonMap) {
-  const elem = document.createElementNS(NS.SVG, jsonMap['element']);
-  for (const attr in jsonMap['attr']) {
-    elem.setAttribute(attr, jsonMap['attr'][attr]);
-  }
+  const elem = document.createElementNS(NS.SVG, jsonMap.element);
+  Object.entries(jsonMap.attr).forEach(([attr, value]) => {
+    elem.setAttribute(attr, value);
+  });
   return elem;
 }
 
@@ -143,12 +146,7 @@ const cleanupSVG = function (svgElem) {
   while (svgElem.firstChild) { svgElem.firstChild.remove(); }
 };
 
-QUnit.module('svgedit.draw.Drawing', {
-  beforeEach () {
-  },
-  afterEach () {
-  }
-});
+QUnit.module('svgedit.draw.Drawing');
 
 QUnit.test('Test draw module', function (assert) {
   assert.expect(4);
@@ -157,7 +155,7 @@ QUnit.test('Test draw module', function (assert) {
   assert.equal(typeof draw, typeof {});
 
   assert.ok(draw.Drawing);
-  assert.equal(typeof draw.Drawing, typeof function () {});
+  assert.equal(typeof draw.Drawing, typeof function () { /* */ });
 });
 
 QUnit.test('Test document creation', function (assert) {
@@ -311,7 +309,7 @@ QUnit.test('Test releaseId()', function (assert) {
 QUnit.test('Test getNumLayers', function (assert) {
   assert.expect(3);
   const drawing = new draw.Drawing(svg);
-  assert.equal(typeof drawing.getNumLayers, typeof function () {});
+  assert.equal(typeof drawing.getNumLayers, typeof function () { /* */ });
   assert.equal(drawing.getNumLayers(), 0);
 
   setupSVGWith3Layers(svg);
@@ -329,7 +327,7 @@ QUnit.test('Test hasLayer', function (assert) {
   const drawing = new draw.Drawing(svg);
   drawing.identifyLayers();
 
-  assert.equal(typeof drawing.hasLayer, typeof function () {});
+  assert.equal(typeof drawing.hasLayer, typeof function () { /* */ });
   assert.ok(!drawing.hasLayer('invalid-layer'));
 
   assert.ok(drawing.hasLayer(LAYER3));
@@ -447,7 +445,7 @@ QUnit.test('Test getCurrentLayer()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.getCurrentLayer);
-  assert.equal(typeof drawing.getCurrentLayer, typeof function () {});
+  assert.equal(typeof drawing.getCurrentLayer, typeof function () { /* */ });
   assert.ok(drawing.getCurrentLayer());
   assert.equal(drawing.getCurrentLayer(), drawing.all_layers[2].getGroup());
 
@@ -462,7 +460,7 @@ QUnit.test('Test setCurrentLayer() and getCurrentLayerName()', function (assert)
   drawing.identifyLayers();
 
   assert.ok(drawing.setCurrentLayer);
-  assert.equal(typeof drawing.setCurrentLayer, typeof function () {});
+  assert.equal(typeof drawing.setCurrentLayer, typeof function () { /* */ });
 
   drawing.setCurrentLayer(LAYER2);
   assert.equal(drawing.getCurrentLayerName(), LAYER2);
@@ -485,7 +483,7 @@ QUnit.test('Test setCurrentLayerName()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.setCurrentLayerName);
-  assert.equal(typeof drawing.setCurrentLayerName, typeof function () {});
+  assert.equal(typeof drawing.setCurrentLayerName, typeof function () { /* */ });
 
   const oldName = drawing.getCurrentLayerName();
   const newName = 'New Name';
@@ -519,7 +517,7 @@ QUnit.test('Test createLayer()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.createLayer);
-  assert.equal(typeof drawing.createLayer, typeof function () {});
+  assert.equal(typeof drawing.createLayer, typeof function () { /* */ });
 
   const NEW_LAYER_NAME = 'Layer A';
   const layerG = drawing.createLayer(NEW_LAYER_NAME, mockHrService);
@@ -553,7 +551,7 @@ QUnit.test('Test mergeLayer()', function (assert) {
   assert.equal(drawing.getCurrentLayer(), layers[2]);
 
   assert.ok(drawing.mergeLayer);
-  assert.equal(typeof drawing.mergeLayer, typeof function () {});
+  assert.equal(typeof drawing.mergeLayer, typeof function () { /* */ });
 
   drawing.mergeLayer(mockHrService);
 
@@ -623,7 +621,7 @@ QUnit.test('Test mergeAllLayers()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.mergeAllLayers);
-  assert.equal(typeof drawing.mergeAllLayers, typeof function () {});
+  assert.equal(typeof drawing.mergeAllLayers, typeof function () { /* */ });
 
   drawing.mergeAllLayers(mockHrService);
 
@@ -661,7 +659,7 @@ QUnit.test('Test cloneLayer()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.cloneLayer);
-  assert.equal(typeof drawing.cloneLayer, typeof function () {});
+  assert.equal(typeof drawing.cloneLayer, typeof function () { /* */ });
 
   const clone = drawing.cloneLayer('clone', mockHrService);
 
@@ -703,7 +701,7 @@ QUnit.test('Test getLayerVisibility()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.getLayerVisibility);
-  assert.equal(typeof drawing.getLayerVisibility, typeof function () {});
+  assert.equal(typeof drawing.getLayerVisibility, typeof function () { /* */ });
   assert.ok(drawing.getLayerVisibility(LAYER1));
   assert.ok(drawing.getLayerVisibility(LAYER2));
   assert.ok(drawing.getLayerVisibility(LAYER3));
@@ -719,7 +717,7 @@ QUnit.test('Test setLayerVisibility()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.setLayerVisibility);
-  assert.equal(typeof drawing.setLayerVisibility, typeof function () {});
+  assert.equal(typeof drawing.setLayerVisibility, typeof function () { /* */ });
 
   drawing.setLayerVisibility(LAYER3, false);
   drawing.setLayerVisibility(LAYER2, true);
@@ -743,7 +741,7 @@ QUnit.test('Test getLayerOpacity()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.getLayerOpacity);
-  assert.equal(typeof drawing.getLayerOpacity, typeof function () {});
+  assert.equal(typeof drawing.getLayerOpacity, typeof function () { /* */ });
   assert.strictEqual(drawing.getLayerOpacity(LAYER1), 1.0);
   assert.strictEqual(drawing.getLayerOpacity(LAYER2), 1.0);
   assert.strictEqual(drawing.getLayerOpacity(LAYER3), 1.0);
@@ -759,7 +757,7 @@ QUnit.test('Test setLayerOpacity()', function (assert) {
   drawing.identifyLayers();
 
   assert.ok(drawing.setLayerOpacity);
-  assert.equal(typeof drawing.setLayerOpacity, typeof function () {});
+  assert.equal(typeof drawing.setLayerOpacity, typeof function () { /* */ });
 
   drawing.setLayerOpacity(LAYER1, 0.4);
   drawing.setLayerOpacity(LAYER2, 'invalid-string');
@@ -802,18 +800,18 @@ QUnit.test('Test svgedit.draw.randomizeIds()', function (assert) {
   // Confirm in LET_DOCUMENT_DECIDE mode that the document decides
   // if there is a nonce.
   let drawing = new draw.Drawing(svgN.cloneNode(true));
-  assert.ok(!!drawing.getNonce());
+  assert.ok(drawing.getNonce());
 
   drawing = new draw.Drawing(svg.cloneNode(true));
   assert.ok(!drawing.getNonce());
 
   // Confirm that a nonce is set once we're in ALWAYS_RANDOMIZE mode.
   draw.randomizeIds(true, drawing);
-  assert.ok(!!drawing.getNonce());
+  assert.ok(drawing.getNonce());
 
   // Confirm new drawings in ALWAYS_RANDOMIZE mode have a nonce.
   drawing = new draw.Drawing(svg.cloneNode(true));
-  assert.ok(!!drawing.getNonce());
+  assert.ok(drawing.getNonce());
 
   drawing.clearNonce();
   assert.ok(!drawing.getNonce());
@@ -822,7 +820,7 @@ QUnit.test('Test svgedit.draw.randomizeIds()', function (assert) {
   // but that their se:nonce attribute is left alone.
   draw.randomizeIds(false, drawing);
   assert.ok(!drawing.getNonce());
-  assert.ok(!!drawing.getSvgElem().getAttributeNS(NS.SE, 'nonce'));
+  assert.ok(drawing.getSvgElem().getAttributeNS(NS.SE, 'nonce'));
 
   drawing = new draw.Drawing(svg.cloneNode(true));
   assert.ok(!drawing.getNonce());
diff --git a/test/history_test.js b/test/history_test.js
index 6b1b7a62..5f9b1c6c 100644
--- a/test/history_test.js
+++ b/test/history_test.js
@@ -3,16 +3,16 @@
 import {NS} from '../editor/namespaces.js';
 import * as transformlist from '../editor/svgtransformlist.js';
 import * as utilities from '../editor/utilities.js';
-import * as history from '../editor/history.js';
+import * as hstory from '../editor/history.js';
 
 // TODO(codedread): Write tests for handling history events.
 
 // Mocked out methods.
-transformlist.changeRemoveElementFromListMap((elem) => {});
+transformlist.changeRemoveElementFromListMap((elem) => { /* */ });
 
 utilities.mock({
   getHref (elem) { return '#foo'; },
-  setHref (elem, val) {},
+  setHref (elem, val) { /* */ },
   getRotationAngle (elem) { return 0; }
 });
 
@@ -36,10 +36,10 @@ QUnit.module('svgedit.history');
 
 class MockCommand {
   constructor (optText) { this.text_ = optText; }
-  apply () {}
-  unapply () {}
+  apply () { /* */ } // eslint-disable-line class-methods-use-this
+  unapply () { /* */ } // eslint-disable-line class-methods-use-this
   getText () { return this.text_; }
-  elements () { return []; }
+  elements () { return []; } // eslint-disable-line class-methods-use-this
 }
 
 /*
@@ -48,9 +48,17 @@ class MockHistoryEventHandler {
 }
 */
 
+/**
+ * Set up tests (with undo manager).
+ * @returns {undefined}
+ */
 function setUp () {
-  undoMgr = new history.UndoManager();
+  undoMgr = new hstory.UndoManager();
 }
+/**
+ * Tear down tests, destroying undo manager.
+ * @returns {undefined}
+ */
 function tearDown () {
   undoMgr = null;
 }
@@ -58,19 +66,19 @@ function tearDown () {
 QUnit.test('Test svgedit.history package', function (assert) {
   assert.expect(13);
 
-  assert.ok(history);
-  assert.ok(history.MoveElementCommand);
-  assert.ok(history.InsertElementCommand);
-  assert.ok(history.ChangeElementCommand);
-  assert.ok(history.RemoveElementCommand);
-  assert.ok(history.BatchCommand);
-  assert.ok(history.UndoManager);
-  assert.equal(typeof history.MoveElementCommand, typeof function () {});
-  assert.equal(typeof history.InsertElementCommand, typeof function () {});
-  assert.equal(typeof history.ChangeElementCommand, typeof function () {});
-  assert.equal(typeof history.RemoveElementCommand, typeof function () {});
-  assert.equal(typeof history.BatchCommand, typeof function () {});
-  assert.equal(typeof history.UndoManager, typeof function () {});
+  assert.ok(hstory);
+  assert.ok(hstory.MoveElementCommand);
+  assert.ok(hstory.InsertElementCommand);
+  assert.ok(hstory.ChangeElementCommand);
+  assert.ok(hstory.RemoveElementCommand);
+  assert.ok(hstory.BatchCommand);
+  assert.ok(hstory.UndoManager);
+  assert.equal(typeof hstory.MoveElementCommand, typeof function () { /* */ });
+  assert.equal(typeof hstory.InsertElementCommand, typeof function () { /* */ });
+  assert.equal(typeof hstory.ChangeElementCommand, typeof function () { /* */ });
+  assert.equal(typeof hstory.RemoveElementCommand, typeof function () { /* */ });
+  assert.equal(typeof hstory.BatchCommand, typeof function () { /* */ });
+  assert.equal(typeof hstory.UndoManager, typeof function () { /* */ });
 });
 
 QUnit.test('Test UndoManager methods', function (assert) {
@@ -86,12 +94,12 @@ QUnit.test('Test UndoManager methods', function (assert) {
   assert.ok(undoMgr.getNextRedoCommandText);
 
   assert.equal(typeof undoMgr, typeof {});
-  assert.equal(typeof undoMgr.addCommandToHistory, typeof function () {});
-  assert.equal(typeof undoMgr.getUndoStackSize, typeof function () {});
-  assert.equal(typeof undoMgr.getRedoStackSize, typeof function () {});
-  assert.equal(typeof undoMgr.resetUndoStack, typeof function () {});
-  assert.equal(typeof undoMgr.getNextUndoCommandText, typeof function () {});
-  assert.equal(typeof undoMgr.getNextRedoCommandText, typeof function () {});
+  assert.equal(typeof undoMgr.addCommandToHistory, typeof function () { /* */ });
+  assert.equal(typeof undoMgr.getUndoStackSize, typeof function () { /* */ });
+  assert.equal(typeof undoMgr.getRedoStackSize, typeof function () { /* */ });
+  assert.equal(typeof undoMgr.resetUndoStack, typeof function () { /* */ });
+  assert.equal(typeof undoMgr.getNextUndoCommandText, typeof function () { /* */ });
+  assert.equal(typeof undoMgr.getNextRedoCommandText, typeof function () { /* */ });
 
   tearDown();
 });
@@ -312,8 +320,8 @@ QUnit.test('Test MoveElementCommand', function (assert) {
   let move = new history.MoveElementCommand(div3, div1, divparent);
   assert.ok(move.unapply);
   assert.ok(move.apply);
-  assert.equal(typeof move.unapply, typeof function () {});
-  assert.equal(typeof move.apply, typeof function () {});
+  assert.equal(typeof move.unapply, typeof function () { /* */ });
+  assert.equal(typeof move.apply, typeof function () { /* */ });
 
   move.unapply();
   assert.equal(divparent.firstElementChild, div3);
@@ -325,7 +333,7 @@ QUnit.test('Test MoveElementCommand', function (assert) {
   assert.equal(divparent.firstElementChild.nextElementSibling, div2);
   assert.equal(divparent.lastElementChild, div3);
 
-  move = new history.MoveElementCommand(div1, null, divparent);
+  move = new hstory.MoveElementCommand(div1, null, divparent);
 
   move.unapply();
   assert.equal(divparent.firstElementChild, div2);
@@ -337,7 +345,7 @@ QUnit.test('Test MoveElementCommand', function (assert) {
   assert.equal(divparent.firstElementChild.nextElementSibling, div2);
   assert.equal(divparent.lastElementChild, div3);
 
-  move = new history.MoveElementCommand(div2, div5, div4);
+  move = new hstory.MoveElementCommand(div2, div5, div4);
 
   move.unapply();
   assert.equal(divparent.firstElementChild, div1);
@@ -361,11 +369,11 @@ QUnit.test('Test InsertElementCommand', function (assert) {
 
   setUp();
 
-  let insert = new history.InsertElementCommand(div3);
+  let insert = new hstory.InsertElementCommand(div3);
   assert.ok(insert.unapply);
   assert.ok(insert.apply);
-  assert.equal(typeof insert.unapply, typeof function () {});
-  assert.equal(typeof insert.apply, typeof function () {});
+  assert.equal(typeof insert.unapply, typeof function () { /* */ });
+  assert.equal(typeof insert.apply, typeof function () { /* */ });
 
   insert.unapply();
   assert.equal(divparent.childElementCount, 2);
@@ -379,7 +387,7 @@ QUnit.test('Test InsertElementCommand', function (assert) {
   assert.equal(div1.nextElementSibling, div2);
   assert.equal(div2.nextElementSibling, div3);
 
-  insert = new history.InsertElementCommand(div2);
+  insert = new hstory.InsertElementCommand(div2);
 
   insert.unapply();
   assert.equal(divparent.childElementCount, 2);
@@ -404,11 +412,11 @@ QUnit.test('Test RemoveElementCommand', function (assert) {
   const div6 = document.createElement('div');
   div6.id = 'div6';
 
-  let remove = new history.RemoveElementCommand(div6, null, divparent);
+  let remove = new hstory.RemoveElementCommand(div6, null, divparent);
   assert.ok(remove.unapply);
   assert.ok(remove.apply);
-  assert.equal(typeof remove.unapply, typeof function () {});
-  assert.equal(typeof remove.apply, typeof function () {});
+  assert.equal(typeof remove.unapply, typeof function () { /* */ });
+  assert.equal(typeof remove.apply, typeof function () { /* */ });
 
   remove.unapply();
   assert.equal(divparent.childElementCount, 4);
@@ -423,7 +431,7 @@ QUnit.test('Test RemoveElementCommand', function (assert) {
   assert.equal(div1.nextElementSibling, div2);
   assert.equal(div2.nextElementSibling, div3);
 
-  remove = new history.RemoveElementCommand(div6, div2, divparent);
+  remove = new hstory.RemoveElementCommand(div6, div2, divparent);
 
   remove.unapply();
   assert.equal(divparent.childElementCount, 4);
@@ -447,12 +455,12 @@ QUnit.test('Test ChangeElementCommand', function (assert) {
   setUp();
 
   div1.setAttribute('title', 'new title');
-  let change = new history.ChangeElementCommand(div1,
+  let change = new hstory.ChangeElementCommand(div1,
     {title: 'old title', class: 'foo'});
   assert.ok(change.unapply);
   assert.ok(change.apply);
-  assert.equal(typeof change.unapply, typeof function () {});
-  assert.equal(typeof change.apply, typeof function () {});
+  assert.equal(typeof change.unapply, typeof function () { /* */ });
+  assert.equal(typeof change.apply, typeof function () { /* */ });
 
   change.unapply();
   assert.equal(div1.getAttribute('title'), 'old title');
@@ -463,7 +471,7 @@ QUnit.test('Test ChangeElementCommand', function (assert) {
   assert.ok(!div1.getAttribute('class'));
 
   div1.textContent = 'inner text';
-  change = new history.ChangeElementCommand(div1,
+  change = new hstory.ChangeElementCommand(div1,
     {'#text': null});
 
   change.unapply();
@@ -473,7 +481,7 @@ QUnit.test('Test ChangeElementCommand', function (assert) {
   assert.equal(div1.textContent, 'inner text');
 
   div1.textContent = '';
-  change = new history.ChangeElementCommand(div1,
+  change = new hstory.ChangeElementCommand(div1,
     {'#text': 'old text'});
 
   change.unapply();
@@ -502,7 +510,7 @@ QUnit.test('Test ChangeElementCommand', function (assert) {
   });
 
   gethrefvalue = '#newhref';
-  change = new history.ChangeElementCommand(rect,
+  change = new hstory.ChangeElementCommand(rect,
     {'#href': '#oldhref'});
   assert.equal(justCalled, 'getHref');
 
@@ -518,12 +526,12 @@ QUnit.test('Test ChangeElementCommand', function (assert) {
 
   const line = document.createElementNS(NS.SVG, 'line');
   line.setAttribute('class', 'newClass');
-  change = new history.ChangeElementCommand(line, {class: 'oldClass'});
+  change = new hstory.ChangeElementCommand(line, {class: 'oldClass'});
 
   assert.ok(change.unapply);
   assert.ok(change.apply);
-  assert.equal(typeof change.unapply, typeof function () {});
-  assert.equal(typeof change.apply, typeof function () {});
+  assert.equal(typeof change.unapply, typeof function () { /* */ });
+  assert.equal(typeof change.apply, typeof function () { /* */ });
 
   change.unapply();
   assert.equal(line.getAttribute('class'), 'oldClass');
@@ -542,15 +550,15 @@ QUnit.test('Test BatchCommand', function (assert) {
   let concatResult = '';
   MockCommand.prototype.apply = function () { concatResult += this.text_; };
 
-  const batch = new history.BatchCommand();
+  const batch = new hstory.BatchCommand();
   assert.ok(batch.unapply);
   assert.ok(batch.apply);
   assert.ok(batch.addSubCommand);
   assert.ok(batch.isEmpty);
-  assert.equal(typeof batch.unapply, typeof function () {});
-  assert.equal(typeof batch.apply, typeof function () {});
-  assert.equal(typeof batch.addSubCommand, typeof function () {});
-  assert.equal(typeof batch.isEmpty, typeof function () {});
+  assert.equal(typeof batch.unapply, typeof function () { /* */ });
+  assert.equal(typeof batch.apply, typeof function () { /* */ });
+  assert.equal(typeof batch.addSubCommand, typeof function () { /* */ });
+  assert.equal(typeof batch.isEmpty, typeof function () { /* */ });
 
   assert.ok(batch.isEmpty());
 
@@ -563,13 +571,13 @@ QUnit.test('Test BatchCommand', function (assert) {
   batch.apply();
   assert.equal(concatResult, 'abc');
 
-  MockCommand.prototype.apply = function () {};
+  MockCommand.prototype.apply = function () { /* */ };
   MockCommand.prototype.unapply = function () { concatResult += this.text_; };
   concatResult = '';
   batch.unapply();
   assert.equal(concatResult, 'cba');
 
-  MockCommand.prototype.unapply = function () {};
+  MockCommand.prototype.unapply = function () { /* */ };
 
   tearDown();
 });
diff --git a/test/jQuery.attr_test.js b/test/jQuery.attr_test.js
index 69ddc8f9..351fdaa1 100644
--- a/test/jQuery.attr_test.js
+++ b/test/jQuery.attr_test.js
@@ -1,5 +1,9 @@
 /* eslint-env qunit */
 
+/* eslint-disable import/unambiguous */
+
+// Todo: Incomplete!
+
 // log function
 QUnit.log((details) => {
   if (window.console && window.console.log) {
diff --git a/test/math_test.js b/test/math_test.js
index b849b672..5b4ec399 100644
--- a/test/math_test.js
+++ b/test/math_test.js
@@ -20,9 +20,9 @@ QUnit.test('Test svgedit.math package', function (assert) {
   assert.ok(math.transformPoint);
   assert.ok(math.isIdentity);
   assert.ok(math.matrixMultiply);
-  assert.equal(typeof math.transformPoint, typeof function () {});
-  assert.equal(typeof math.isIdentity, typeof function () {});
-  assert.equal(typeof math.matrixMultiply, typeof function () {});
+  assert.equal(typeof math.transformPoint, typeof function () { /* */ });
+  assert.equal(typeof math.isIdentity, typeof function () { /* */ });
+  assert.equal(typeof math.matrixMultiply, typeof function () { /* */ });
 });
 
 QUnit.test('Test svgedit.math.transformPoint() function', function (assert) {
diff --git a/test/qunit/qunit-assert-almostEquals.js b/test/qunit/qunit-assert-almostEquals.js
index d7f679a8..e33265ce 100644
--- a/test/qunit/qunit-assert-almostEquals.js
+++ b/test/qunit/qunit-assert-almostEquals.js
@@ -1,5 +1,12 @@
 const NEAR_ZERO = 5e-6; // 0.000005, Firefox fails at higher levels of precision.
 
+/**
+ * Checks that the supplied values are equal with a high though not absolute degree of precision.
+ * @param {Float} actual
+ * @param {Float} expected
+ * @param {string} message
+ * @returns {undefined}
+ */
 function almostEquals (actual, expected, message) {
   message = message || (actual + ' did not equal ' + expected);
   this.pushResult({
@@ -10,6 +17,10 @@ function almostEquals (actual, expected, message) {
   });
 }
 
+/**
+ * @param {external:qunit} QUnit
+ * @returns {external:qunit} The same instance passed in after extending
+ */
 export default function extend (QUnit) {
   QUnit.extend(QUnit.assert, {
     almostEquals
diff --git a/test/qunit/qunit-assert-close.js b/test/qunit/qunit-assert-close.js
index 5f8646ad..c0dfe3b2 100644
--- a/test/qunit/qunit-assert-close.js
+++ b/test/qunit/qunit-assert-close.js
@@ -10,7 +10,7 @@
  * @param {string} [message] Defaults to structured message
  * @returns {undefined}
  */
-function close (actual, expected, maxDifference, message) {
+function close (actual, expected, maxDifference, message) { // eslint-disable-line no-shadow
   const actualDiff = (actual === expected) ? 0 : Math.abs(actual - expected),
     result = actualDiff <= maxDifference;
   message = message || (actual + ' should be within ' + maxDifference + ' (inclusive) of ' + expected + (result ? '' : '. Actual: ' + actualDiff));
@@ -96,6 +96,10 @@ function notClosePercent (actual, expected, minPercentDifference, message) {
   this.pushResult({result, actual, expected, message});
 }
 
+/**
+ * @param {external:qunit} QUnit
+ * @returns {external:qunit} The same instance passed in after extending
+ */
 export default function extend (QUnit) {
   QUnit.extend(QUnit.assert, {
     close,
diff --git a/test/qunit/qunit-assert-expectOutOfBoundsException.js b/test/qunit/qunit-assert-expectOutOfBoundsException.js
index 20d911c3..895eec2a 100644
--- a/test/qunit/qunit-assert-expectOutOfBoundsException.js
+++ b/test/qunit/qunit-assert-expectOutOfBoundsException.js
@@ -1,3 +1,10 @@
+/**
+ * Expects an out of bounds `INDEX_SIZE_ERR` exception.
+ * @param {GenericObject} obj
+ * @param {GenericCallback} fn
+ * @param {Any} arg1
+ * @returns {undefined}
+ */
 function expectOutOfBoundsException (obj, fn, arg1) {
   const expected = true;
   const message = 'Caught an INDEX_SIZE_ERR exception';
@@ -10,9 +17,13 @@ function expectOutOfBoundsException (obj, fn, arg1) {
     }
   }
   const actual = result;
-  console.log('aaa', result, actual, expected);
   this.pushResult({result, actual, expected, message});
 }
+
+/**
+ * @param {external:qunit} QUnit
+ * @returns {external:qunit} The same instance passed in after extending
+ */
 export default function extend (QUnit) {
   QUnit.extend(QUnit.assert, {
     expectOutOfBoundsException
diff --git a/test/recalculate_test.js b/test/recalculate_test.js
index e7b86d5e..8b069d9d 100644
--- a/test/recalculate_test.js
+++ b/test/recalculate_test.js
@@ -20,6 +20,11 @@ const svg = document.createElementNS(NS.SVG, 'svg');
 svgroot.append(svg);
 
 let elemId = 1;
+
+/**
+ * Initilize modules to set up the tests.
+ * @returns {undefined}
+ */
 function setUp () {
   utilities.init(
     /**
@@ -39,7 +44,7 @@ function setUp () {
       getGridSnapping () { return false; },
       getDrawing () {
         return {
-          getNextId () { return '' + elemId++; }
+          getNextId () { return String(elemId++); }
         };
       }
     }
@@ -51,13 +56,17 @@ function setUp () {
     {
       getSVGRoot () { return svg; },
       getStartTransform () { return ''; },
-      setStartTransform () {}
+      setStartTransform () { /* */ }
     }
   );
 }
 
 let elem;
 
+/**
+ * Initialize for tests and set up `rect` element.
+ * @returns {undefined}
+ */
 function setUpRect () {
   setUp();
   elem = document.createElementNS(NS.SVG, 'rect');
@@ -68,6 +77,10 @@ function setUpRect () {
   svg.append(elem);
 }
 
+/**
+ * Initialize for tests and set up `text` element with `tspan` child.
+ * @returns {undefined}
+ */
 function setUpTextWithTspan () {
   setUp();
   elem = document.createElementNS(NS.SVG, 'text');
@@ -84,6 +97,10 @@ function setUpTextWithTspan () {
   svg.append(elem);
 }
 
+/**
+ * Tear down the tests (empty the svg element).
+ * @returns {undefined}
+ */
 function tearDown () {
   while (svg.hasChildNodes()) {
     svg.firstChild.remove();
diff --git a/test/select_test.js b/test/select_test.js
index 8f4e9523..9b7570dd 100644
--- a/test/select_test.js
+++ b/test/select_test.js
@@ -1,6 +1,6 @@
 /* eslint-env qunit */
-import {NS} from '../editor/namespaces.js';
 import * as select from '../editor/select.js';
+import {NS} from '../editor/namespaces.js';
 
 // log function
 QUnit.log((details) => {
@@ -23,16 +23,20 @@ const mockConfig = {
 */
 const mockFactory = {
   createSVGElement (jsonMap) {
-    const elem = document.createElementNS(NS.SVG, jsonMap['element']);
-    for (const attr in jsonMap.attr) {
-      elem.setAttribute(attr, jsonMap.attr[attr]);
-    }
+    const elem = document.createElementNS(NS.SVG, jsonMap.element);
+    Object.entries(jsonMap.attr).forEach(([attr, value]) => {
+      elem.setAttribute(attr, value);
+    });
     return elem;
   },
   svgRoot () { return svgroot; },
   svgContent () { return svgcontent; }
 };
 
+/**
+ * Potentially reusable test set-up.
+ * @returns {undefined}
+ */
 function setUp () {
   svgroot = mockFactory.createSVGElement({
     element: 'svg',
@@ -66,6 +70,10 @@ function setUpWithInit () {
 }
 */
 
+/**
+ * Tear down the test by emptying our sandbox area.
+ * @returns {undefined}
+ */
 function tearDown () {
   while (sandbox.hasChildNodes()) {
     sandbox.firstChild.remove();
@@ -81,10 +89,10 @@ QUnit.test('Test svgedit.select package', function (assert) {
   assert.ok(select.init);
   assert.ok(select.getSelectorManager);
   assert.equal(typeof select, typeof {});
-  assert.equal(typeof select.Selector, typeof function () {});
-  assert.equal(typeof select.SelectorManager, typeof function () {});
-  assert.equal(typeof select.init, typeof function () {});
-  assert.equal(typeof select.getSelectorManager, typeof function () {});
+  assert.equal(typeof select.Selector, typeof function () { /* */ });
+  assert.equal(typeof select.SelectorManager, typeof function () { /* */ });
+  assert.equal(typeof select.init, typeof function () { /* */ });
+  assert.equal(typeof select.getSelectorManager, typeof function () { /* */ });
 });
 
 QUnit.test('Test Selector DOM structure', function (assert) {
diff --git a/test/sinon/sinon-qunit.js b/test/sinon/sinon-qunit.js
index d719de78..bf7637de 100644
--- a/test/sinon/sinon-qunit.js
+++ b/test/sinon/sinon-qunit.js
@@ -1,6 +1,20 @@
 // Adapted from https://www.npmjs.com/package/sinon-test
 
-export default function ({sinon, QUnit}) {
+/**
+ * @external QUnit
+ */
+/**
+ * @external sinon
+ */
+
+/**
+ * Adds methods to Sinon using a QUnit implementation.
+ * @param {PlainObject} implementations
+ * @param {external:sinon} implementations.sinon
+ * @param {external:QUnit} implementations.QUnit
+ * @returns {undefined}
+ */
+export default function sinonQunit ({sinon, QUnit}) {
   sinon.assert.fail = function (msg) {
     QUnit.ok(false, msg);
   };
@@ -10,7 +24,7 @@ export default function ({sinon, QUnit}) {
   };
 
   const qTest = QUnit.test;
-  QUnit.test = function (testName, callback) {
+  QUnit.test = function (testName, callback) { // eslint-disable-line promise/prefer-await-to-callbacks
     return qTest(testName, sinon.test(callback));
   };
 }
diff --git a/test/svgtransformlist_test.js b/test/svgtransformlist_test.js
index a8732223..f2ce5691 100644
--- a/test/svgtransformlist_test.js
+++ b/test/svgtransformlist_test.js
@@ -21,6 +21,10 @@ QUnit.log((details) => {
 const svgroot = document.querySelector('#svgroot');
 let svgcontent, rect, circle;
 
+/**
+ * Set up tests, adding elements.
+ * @returns {undefined}
+ */
 function setUp () {
   svgcontent = svgroot.appendChild(document.createElementNS(NS.SVG, 'svg'));
   rect = svgcontent.appendChild(document.createElementNS(NS.SVG, 'rect'));
@@ -29,6 +33,10 @@ function setUp () {
   circle.id = 'c';
 }
 
+/**
+ * Tear down tests, emptying SVG root, and resetting list map.
+ * @returns {undefined}
+ */
 function tearDown () {
   transformlist.resetListMap();
   while (svgroot.hasChildNodes()) {
@@ -82,7 +90,7 @@ QUnit.test('Test SVGTransformList.initialize()', function (assert) {
   const t = svgcontent.createSVGTransform();
   assert.ok(t);
   assert.ok(rxform.initialize);
-  assert.equal(typeof rxform.initialize, typeof function () {});
+  assert.equal(typeof rxform.initialize, typeof function () { /* */ });
   rxform.initialize(t);
   assert.equal(rxform.numberOfItems, 1);
   assert.equal(cxform.numberOfItems, 0);
@@ -110,8 +118,8 @@ QUnit.test('Test SVGTransformList.appendItem() and getItem()', function (assert)
 
   assert.ok(rxform.appendItem);
   assert.ok(rxform.getItem);
-  assert.equal(typeof rxform.appendItem, typeof function () {});
-  assert.equal(typeof rxform.getItem, typeof function () {});
+  assert.equal(typeof rxform.appendItem, typeof function () { /* */ });
+  assert.equal(typeof rxform.getItem, typeof function () { /* */ });
 
   rxform.appendItem(t1);
   rxform.appendItem(t2);
@@ -145,7 +153,7 @@ QUnit.test('Test SVGTransformList.removeItem()', function (assert) {
   const t1 = svgcontent.createSVGTransform(),
     t2 = svgcontent.createSVGTransform();
   assert.ok(rxform.removeItem);
-  assert.equal(typeof rxform.removeItem, typeof function () {});
+  assert.equal(typeof rxform.removeItem, typeof function () { /* */ });
   rxform.appendItem(t1);
   rxform.appendItem(t2);
 
@@ -168,7 +176,7 @@ QUnit.test('Test SVGTransformList.replaceItem()', function (assert) {
   const cxform = transformlist.getTransformList(circle);
 
   assert.ok(rxform.replaceItem);
-  assert.equal(typeof rxform.replaceItem, typeof function () {});
+  assert.equal(typeof rxform.replaceItem, typeof function () { /* */ });
 
   const t1 = svgcontent.createSVGTransform(),
     t2 = svgcontent.createSVGTransform(),
@@ -205,7 +213,7 @@ QUnit.test('Test SVGTransformList.insertItemBefore()', function (assert) {
   const cxform = transformlist.getTransformList(circle);
 
   assert.ok(rxform.insertItemBefore);
-  assert.equal(typeof rxform.insertItemBefore, typeof function () {});
+  assert.equal(typeof rxform.insertItemBefore, typeof function () { /* */ });
 
   const t1 = svgcontent.createSVGTransform(),
     t2 = svgcontent.createSVGTransform(),
diff --git a/test/test1.js b/test/test1.js
index 2efffa02..30117dce 100644
--- a/test/test1.js
+++ b/test/test1.js
@@ -40,7 +40,8 @@ const svgCanvas = new SvgCanvas(
     extensions: ['ext-arrows.js', 'ext-connector.js', 'ext-eyedropper.js'],
     initTool: 'select',
     wireframe: false
-  });
+  }
+);
 
 const
   // svgroot = document.getElementById('svgroot'),
@@ -188,7 +189,7 @@ QUnit.test('Test import math elements inside a foreignObject', function (assert)
   // see Bug https://bugs.webkit.org/show_bug.cgi?id=35042
   const math = fo.firstChild;
 
-  assert.equal(!!math, true, 'Math element exists');
+  assert.equal(Boolean(math), true, 'Math element exists');
   assert.equal(math.nodeName, 'math', 'Math element has the proper nodeName');
   assert.equal(math.getAttribute('id'), 'm', 'Math element has an id');
   assert.equal(math.namespaceURI, 'http://www.w3.org/1998/Math/MathML', 'Preserved MathML namespace');
@@ -227,12 +228,13 @@ QUnit.test('Test importing SVG remaps IDs', function (assert) {
 
   /* const doc = */ svgCanvas.setSvgString(
     '<svg width="640" height="480" xmlns="http://www.w3.org/2000/svg">' +
-    '<g><title>Layer 1</title>' +
-      '<ellipse id="svg_1" cx="200" cy="200" rx="50" ry="20" fill="blue"/>' +
-      '<ellipse id="svg_2" cx="300" cy="100" rx="40" ry="30" fill="green"/>' +
-      '<ellipse id="svg_3" cx="300" cy="100" rx="40" ry="30" fill="green"/>' +
-    '</g>' +
-  '</svg>');
+      '<g><title>Layer 1</title>' +
+        '<ellipse id="svg_1" cx="200" cy="200" rx="50" ry="20" fill="blue"/>' +
+        '<ellipse id="svg_2" cx="300" cy="100" rx="40" ry="30" fill="green"/>' +
+        '<ellipse id="svg_3" cx="300" cy="100" rx="40" ry="30" fill="green"/>' +
+      '</g>' +
+    '</svg>'
+  );
 
   svgCanvas.importSvgString(
     '<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg" xmlns:xl="http://www.w3.org/1999/xlink">' +
diff --git a/test/ui-tests/accessibility.js b/test/ui-tests/accessibility.js
index e025f763..e2001e5f 100644
--- a/test/ui-tests/accessibility.js
+++ b/test/ui-tests/accessibility.js
@@ -6,14 +6,14 @@ import axeCheck from 'axe-testcafe';
 fixture`TestCafe Axe accessibility tests (Editor - no parameters)`
   .page`http://localhost:8000/editor/svg-editor.html`;
 
-test('Editor - no parameters', async t => {
+test('Editor - no parameters', async (t) => {
   await axeCheck(t); // , axeContent, axeOptions: https://github.com/dequelabs/axe-core/blob/develop/doc/API.md#api-name-axerun
 });
 
 fixture`TestCafe Axe accessibility tests (Editor - with all extensions)`
   .page`http://localhost:8000/editor/svg-editor.html?extensions=ext-arrows.js,ext-closepath.js,ext-foreignobject.js,ext-helloworld.js,ext-mathjax.js,ext-php_savefile.js,ext-server_moinsave.js,ext-server_opensave.js,ext-webappfind.js,ext-xdomain-messaging.js`;
 
-test('Editor ES - with all extensions', async t => {
+test('Editor ES - with all extensions', async (t) => {
   await axeCheck(t); // , axeContent, axeOptions: https://github.com/dequelabs/axe-core/blob/develop/doc/API.md#api-name-axerun
 });
 
diff --git a/test/ui-tests/ui.js b/test/ui-tests/ui.js
index 94511680..6c15c01a 100644
--- a/test/ui-tests/ui.js
+++ b/test/ui-tests/ui.js
@@ -6,14 +6,14 @@ import {Selector} from 'testcafe';
 fixture`TestCafe UI tests`
   .page`http://localhost:8000/editor/svg-editor.html`;
 
-test('Editor - No parameters: Export button', async t => {
+test('Editor - No parameters: Export button', async (t) => {
   await t
     .click('#dialog_buttons > input[type=button][value=OK]')
     .click('#main_icon')
     .expect(Selector('#tool_export')).ok('Has open button');
 });
 
-test('Editor - No parameters: Export button clicking', async t => {
+test('Editor - No parameters: Export button clicking', async (t) => {
   await t
     .click('#dialog_buttons > input[type=button][value=OK]')
     .click('#main_icon')
diff --git a/test/units_test.js b/test/units_test.js
index cf386dc7..09248998 100644
--- a/test/units_test.js
+++ b/test/units_test.js
@@ -8,6 +8,10 @@ QUnit.log((details) => {
   }
 });
 
+/**
+ * Set up tests, supplying mock data.
+ * @returns {undefined}
+ */
 function setUp () {
   units.init(
     /**
@@ -35,7 +39,7 @@ QUnit.test('Test svgedit.units.shortFloat()', function (assert) {
   setUp();
 
   assert.ok(units.shortFloat);
-  assert.equal(typeof units.shortFloat, typeof function () {});
+  assert.equal(typeof units.shortFloat, typeof function () { /* */ });
 
   const {shortFloat} = units;
   assert.equal(shortFloat(0.00000001), 0);
@@ -51,7 +55,7 @@ QUnit.test('Test svgedit.units.isValidUnit()', function (assert) {
   setUp();
 
   assert.ok(units.isValidUnit);
-  assert.equal(typeof units.isValidUnit, typeof function () {});
+  assert.equal(typeof units.isValidUnit, typeof function () { /* */ });
 
   const {isValidUnit} = units;
   assert.ok(isValidUnit('0'));
@@ -79,7 +83,7 @@ QUnit.test('Test svgedit.units.convertUnit()', function (assert) {
   setUp();
 
   assert.ok(units.convertUnit);
-  assert.equal(typeof units.convertUnit, typeof function () {});
+  assert.equal(typeof units.convertUnit, typeof function () { /* */ });
   // cm in default setup
   assert.equal(units.convertUnit(42), 1.1113);
   assert.equal(units.convertUnit(42, 'px'), 42);
diff --git a/test/utilities_bbox_test.js b/test/utilities_bbox_test.js
index c5ff45de..a436567c 100644
--- a/test/utilities_bbox_test.js
+++ b/test/utilities_bbox_test.js
@@ -16,14 +16,25 @@ QUnit.log((details) => {
   }
 });
 
+/**
+ * Create an SVG element for a mock.
+ * @param {module:utilities.SVGElementJSON} jsonMap
+ * @returns {SVGElement}
+ */
 function mockCreateSVGElement (jsonMap) {
-  const elem = document.createElementNS(NS.SVG, jsonMap['element']);
-  for (const attr in jsonMap['attr']) {
-    elem.setAttribute(attr, jsonMap['attr'][attr]);
-  }
+  const elem = document.createElementNS(NS.SVG, jsonMap.element);
+  Object.entries(jsonMap.attr).forEach(([attr, value]) => {
+    elem.setAttribute(attr, value);
+  });
   return elem;
 }
 let mockaddSVGElementFromJsonCallCount = 0;
+
+/**
+ * Mock of {@link module:utilities.EditorContext#addSVGElementFromJson}.
+ * @param {module:utilities.SVGElementJSON} json
+ * @returns {SVGElement}
+ */
 function mockaddSVGElementFromJson (json) {
   const elem = mockCreateSVGElement(json);
   svgroot.append(elem);
@@ -32,7 +43,7 @@ function mockaddSVGElementFromJson (json) {
 }
 const mockPathActions = {
   resetOrientation (pth) {
-    if (pth == null || pth.nodeName !== 'path') { return false; }
+    if (utilities.isNullish(pth) || pth.nodeName !== 'path') { return false; }
     const tlist = transformlist.getTransformList(pth);
     const m = math.transformListToTransform(tlist).matrix;
     tlist.clear();
@@ -57,6 +68,7 @@ const mockPathActions = {
       path.replacePathSeg(type, i, pts, pth);
     }
     // path.reorientGrads(pth, m);
+    return undefined;
   }
 };
 
@@ -75,8 +87,6 @@ QUnit.module('svgedit.utilities_bbox', {
     transformlist.resetListMap();
     path.init(null);
     mockaddSVGElementFromJsonCallCount = 0;
-  },
-  afterEach () {
   }
 });
 
@@ -167,7 +177,7 @@ QUnit.test('Test getBBoxWithTransform and a rotation transform', function (asser
 
   const rect = {x: 10, y: 10, width: 10, height: 20};
   const angle = 45;
-  const origin = {x: 15, y: 20};
+  const origin = {x: 15, y: 20}; // eslint-disable-line no-shadow
   elem = mockCreateSVGElement({
     element: 'rect',
     attr: {id: 'rect2', x: rect.x, y: rect.y, width: rect.width, height: rect.height, transform: 'rotate(' + angle + ' ' + origin.x + ',' + origin.y + ')'}
@@ -256,7 +266,7 @@ QUnit.test('Test getBBoxWithTransform with rotation and matrix transforms', func
 
   const rect = {x: 10, y: 10, width: 10, height: 20};
   const angle = 45;
-  const origin = {x: 15, y: 20};
+  const origin = {x: 15, y: 20}; // eslint-disable-line no-shadow
   tx = 10; // tx right
   ty = 10; // tx down
   txInRotatedSpace = Math.sqrt(tx * tx + ty * ty); // translate in rotated 45 space.
@@ -443,10 +453,23 @@ QUnit.test('Test getStrokedBBox with no stroke-width attribute', function (asser
   g.remove();
 });
 
+/**
+ * Returns radians for degrees.
+ * @param {Float} degrees
+ * @returns {Float}
+ */
 function radians (degrees) {
   return degrees * Math.PI / 180;
 }
-function rotatePoint (point, angle, origin) {
+
+/**
+ *
+ * @param {module:utilities.BBoxObject} point
+ * @param {Float} angle
+ * @param {module:math.XYObject} origin
+ * @returns {module:math.XYObject}
+ */
+function rotatePoint (point, angle, origin) { // eslint-disable-line no-shadow
   if (!origin) {
     origin = {x: 0, y: 0};
   }
@@ -458,7 +481,14 @@ function rotatePoint (point, angle, origin) {
     y: x * Math.sin(theta) + y * Math.cos(theta) + origin.y
   };
 }
-function rotateRect (rect, angle, origin) {
+/**
+ *
+ * @param {module:utilities.BBoxObject} rect
+ * @param {Float} angle
+ * @param {module:math.XYObject} origin
+ * @returns {module:utilities.BBoxObject}
+ */
+function rotateRect (rect, angle, origin) { // eslint-disable-line no-shadow
   const tl = rotatePoint({x: rect.x, y: rect.y}, angle, origin);
   const tr = rotatePoint({x: rect.x + rect.width, y: rect.y}, angle, origin);
   const br = rotatePoint({x: rect.x + rect.width, y: rect.y + rect.height}, angle, origin);
diff --git a/test/utilities_performance_test.js b/test/utilities_performance_test.js
index 7db1e0d1..aa65a7a8 100644
--- a/test/utilities_performance_test.js
+++ b/test/utilities_performance_test.js
@@ -14,13 +14,24 @@ QUnit.log((details) => {
 
 const currentLayer = document.getElementById('layer1');
 
+/**
+ * Create an SVG element for a mock.
+ * @param {module:utilities.SVGElementJSON} jsonMap
+ * @returns {SVGElement}
+ */
 function mockCreateSVGElement (jsonMap) {
-  const elem = document.createElementNS(NS.SVG, jsonMap['element']);
-  for (const attr in jsonMap['attr']) {
-    elem.setAttribute(attr, jsonMap['attr'][attr]);
-  }
+  const elem = document.createElementNS(NS.SVG, jsonMap.element);
+  Object.entries(jsonMap.attr).forEach(([attr, value]) => {
+    elem.setAttribute(attr, value);
+  });
   return elem;
 }
+
+/**
+ * Mock of {@link module:utilities.EditorContext#addSVGElementFromJson}.
+ * @param {module:utilities.SVGElementJSON} json
+ * @returns {SVGElement}
+ */
 function mockaddSVGElementFromJson (json) {
   const elem = mockCreateSVGElement(json);
   currentLayer.append(elem);
@@ -31,27 +42,28 @@ function mockaddSVGElementFromJson (json) {
 const groupWithMatrixTransform = document.getElementById('svg_group_with_matrix_transform');
 const textWithMatrixTransform = document.getElementById('svg_text_with_matrix_transform');
 
+/**
+ * Toward performance testing, fill document with clones of element.
+ * @param {SVGElement} elem
+ * @param {Integer} count
+ * @returns {undefined}
+ */
 function fillDocumentByCloningElement (elem, count) {
   const elemId = elem.getAttribute('id') + '-';
   for (let index = 0; index < count; index++) {
     const clone = elem.cloneNode(true); // t: deep clone
     // Make sure you set a unique ID like a real document.
     clone.setAttribute('id', elemId + index);
-    const parent = elem.parentNode;
-    parent.append(clone);
+    const {parentNode} = elem;
+    parentNode.append(clone);
   }
 }
 
-QUnit.module('svgedit.utilities_performance', {
-  beforeEach () {
-  },
-  afterEach () {
-  }
-});
+QUnit.module('svgedit.utilities_performance');
 
 const mockPathActions = {
   resetOrientation (path) {
-    if (path == null || path.nodeName !== 'path') { return false; }
+    if (utilities.isNullish(path) || path.nodeName !== 'path') { return false; }
     const tlist = transformlist.getTransformList(path);
     const m = math.transformListToTransform(tlist).matrix;
     tlist.clear();
@@ -64,10 +76,13 @@ const mockPathActions = {
     for (let i = 0; i < len; ++i) {
       const seg = segList.getItem(i);
       const type = seg.pathSegType;
-      if (type === 1) { continue; }
+      if (type === 1) {
+        continue;
+      }
       const pts = [];
       ['', 1, 2].forEach(function (n, j) {
-        const x = seg['x' + n], y = seg['y' + n];
+        const x = seg['x' + n],
+          y = seg['y' + n];
         if (x !== undefined && y !== undefined) {
           const pt = math.transformPoint(x, y, m);
           pts.splice(pts.length, 0, pt.x, pt.y);
@@ -77,6 +92,7 @@ const mockPathActions = {
     }
 
     // utilities.reorientGrads(path, m);
+    return undefined;
   }
 };
 
@@ -144,11 +160,11 @@ QUnit.test('Test svgCanvas.getStrokedBBox() performance with matrix transforms',
 
   // The second pass is two to ten times faster.
   setTimeout(function () {
-    const count = children.length;
+    const ct = children.length;
 
-    const start = lastTime = now = Date.now();
+    const strt = lastTime = now = Date.now();
     // Skip the first child which is the title.
-    for (let index = 1; index < count; index++) {
+    for (let index = 1; index < ct; index++) {
       const child = children[index];
       /* const obj = */ getStrokedBBox([child], mockaddSVGElementFromJson, mockPathActions);
       now = Date.now(); const delta = now - lastTime; lastTime = now;
@@ -157,10 +173,10 @@ QUnit.test('Test svgCanvas.getStrokedBBox() performance with matrix transforms',
       max = Math.max(max, delta);
     }
 
-    total = lastTime - start;
-    const ave = total / count;
-    assert.ok(ave < 2, 'svgedit.utilities.getStrokedBBox average execution time is less than 1 ms');
-    console.log('Pass2 svgCanvas.getStrokedBBox total ms ' + total + ', ave ms ' + ave.toFixed(1) + ',\t min/max ' + min + ' ' + max);
+    total = lastTime - strt;
+    const avg = total / ct;
+    assert.ok(avg < 2, 'svgedit.utilities.getStrokedBBox average execution time is less than 1 ms');
+    console.log('Pass2 svgCanvas.getStrokedBBox total ms ' + total + ', ave ms ' + avg.toFixed(1) + ',\t min/max ' + min + ' ' + max);
 
     done();
   });
diff --git a/test/utilities_test.js b/test/utilities_test.js
index cd4c017b..919166c7 100644
--- a/test/utilities_test.js
+++ b/test/utilities_test.js
@@ -1,8 +1,8 @@
 /* eslint-env qunit */
 
-import {NS} from '../editor/namespaces.js';
-import * as utilities from '../editor/utilities.js';
 import * as browser from '../editor/browser.js';
+import * as utilities from '../editor/utilities.js';
+import {NS} from '../editor/namespaces.js';
 
 // log function
 QUnit.log((details) => {
@@ -11,19 +11,29 @@ QUnit.log((details) => {
   }
 });
 
+/**
+ * Create an element for test.
+ * @param {module:utilities.SVGElementJSON} jsonMap
+ * @returns {SVGElement}
+ */
 function mockCreateSVGElement (jsonMap) {
-  const elem = document.createElementNS(NS.SVG, jsonMap['element']);
-  for (const attr in jsonMap['attr']) {
-    elem.setAttribute(attr, jsonMap['attr'][attr]);
-  }
+  const elem = document.createElementNS(NS.SVG, jsonMap.element);
+  Object.entries(jsonMap.attr).forEach(([attr, value]) => {
+    elem.setAttribute(attr, value);
+  });
   return elem;
 }
+/**
+ * Adds SVG Element per parameters and appends to root.
+ * @param {module:utilities.SVGElementJSON} json
+ * @returns {SVGElement}
+ */
 function mockaddSVGElementFromJson (json) {
   const elem = mockCreateSVGElement(json);
   svgroot.append(elem);
   return elem;
 }
-const mockPathActions = {resetOrientation () {}};
+const mockPathActions = {resetOrientation () { /* */ }};
 let mockHistorySubCommands = [];
 const mockHistory = {
   BatchCommand: class {
@@ -34,7 +44,8 @@ const mockHistory = {
     }
   },
   RemoveElementCommand: class {
-    constructor (elem, nextSibling, parent) { // Longhand needed since used as a constructor
+    // Longhand needed since used as a constructor
+    constructor (elem, nextSibling, parent) {
       this.elem = elem;
       this.nextSibling = nextSibling;
       this.parent = parent;
@@ -51,9 +62,28 @@ const mockCount = {
   addToSelection: 0,
   addCommandToHistory: 0
 };
-function mockClearSelection () { mockCount.clearSelection++; }
-function mockAddToSelection () { mockCount.addToSelection++; }
-function mockAddCommandToHistory () { mockCount.addCommandToHistory++; }
+
+/**
+ * Increments clear seleciton count for mock test.
+ * @returns {undefined}
+ */
+function mockClearSelection () {
+  mockCount.clearSelection++;
+}
+/**
+* Increments add selection count for mock test.
+ * @returns {undefined}
+ */
+function mockAddToSelection () {
+  mockCount.addToSelection++;
+}
+/**
+* Increments add command to history count for mock test.
+ * @returns {undefined}
+ */
+function mockAddCommandToHistory () {
+  mockCount.addCommandToHistory++;
+}
 
 const svg = document.createElementNS(NS.SVG, 'svg');
 const sandbox = document.getElementById('sandbox');
@@ -70,8 +100,7 @@ QUnit.module('svgedit.utilities', {
     mockCount.addToSelection = 0;
     mockCount.addCommandToHistory = 0;
   },
-  afterEach () {
-  }
+  afterEach () { /* */ }
 });
 
 QUnit.test('Test svgedit.utilities package', function (assert) {
@@ -79,7 +108,7 @@ QUnit.test('Test svgedit.utilities package', function (assert) {
 
   assert.ok(utilities);
   assert.ok(utilities.toXml);
-  assert.equal(typeof utilities.toXml, typeof function () {});
+  assert.equal(typeof utilities.toXml, typeof function () { /* */ });
 });
 
 QUnit.test('Test svgedit.utilities.toXml() function', function (assert) {
@@ -259,6 +288,10 @@ QUnit.test('Test getPathDFromElement', function (assert) {
 });
 
 QUnit.test('Test getBBoxOfElementAsPath', function (assert) {
+  /**
+   * Wrap `utilities.getBBoxOfElementAsPath` to convert bbox to object for testing.
+   * @implements {module:utilities.getBBoxOfElementAsPath}
+   */
   function getBBoxOfElementAsPath (elem, addSVGElementFromJson, pathActions) {
     const bbox = utilities.getBBoxOfElementAsPath(elem, addSVGElementFromJson, pathActions);
     return utilities.bboxToObj(bbox); // need this for assert.equal() to work.