eslint: enforce use of const when variable not modified

.eslintrc.js

@@ -32,12 +32,17 @@ module.exports = {
     /** @todo cognitive complexity should be much lower (25-50?) */
     "sonarjs/cognitive-complexity": [ "warn", 200 ],
     /** @todo no param reassign creates too many warnings but should be a warning */
-    "comma-dangle": [ "error" ],
     "no-param-reassign": "off",
+    /** @todo no use before define creates too many warnings but should be a warning */
+    "no-use-before-define": "off",
+    /** @todo camel case creates too many warnings but should be a warning */
+    "camelcase": "off",
+    "comma-dangle": [ "error" ],
     "node/no-unsupported-features/es-syntax": 0,
     "no-unused-vars": [ "error", { "argsIgnorePattern": "^_" } ],
     "sonarjs/no-duplicate-string": 0,
     "semi" : "error",
+    "prefer-const": "error",
     "no-trailing-spaces": "error",
     "array-bracket-spacing": [ "error", "always" ],
     "comma-spacing": "error",
@@ -85,7 +90,8 @@ module.exports = {
     {
       files: [ 'src/editor/locale/*.js' ],
       rules: { // lang files may have long length
-        "max-len": "off"
+        "max-len": "off",
+        "camelcase": "off"
       }
     }
   ]

cypress/integration/unit/recalculate.js

@@ -33,7 +33,7 @@ describe('recalculate', function () {
       return this._storage.has(element) && this._storage.get(element).has(key);
     },
     remove: function (element, key) {
-      let ret = this._storage.get(element).delete(key);
+      const ret = this._storage.get(element).delete(key);
       if (!this._storage.get(element).size === 0) {
         this._storage.delete(element);
       }

cypress/integration/unit/select.js

@@ -27,7 +27,7 @@ describe('select', function () {
       return this._storage.has(element) && this._storage.get(element).has(key);
     },
     remove: function (element, key) {
-      let ret = this._storage.get(element).delete(key);
+      const ret = this._storage.get(element).delete(key);
       if (!this._storage.get(element).size === 0) {
         this._storage.delete(element);
       }

src/editor/Editor.js

@@ -281,11 +281,11 @@ class Editor extends EditorStartup {
       parentSelector = document;
     }
 
-    let parents = [];
+    const parents = [];
     let p = el.parentNode;
 
     while (p !== parentSelector) {
-      let o = p;
+      const o = p;
       parents.push(o);
       p = o.parentNode;
     }

src/editor/EditorStartup.js

@@ -255,7 +255,7 @@ class EditorStartup {
     });
 
     function addListenerMulti(element, eventNames, listener) {
-      let events = eventNames.split(' ');
+      const events = eventNames.split(' ');
       for (let i=0, iLen=events.length; i<iLen; i++) {
         element.addEventListener(events[i], listener, false);
       }

src/editor/components/jgraduate/Util.js

@@ -21,7 +21,7 @@ export function isObject(item) {
 }
 
 export function mergeDeep(target, source) {
-  let output = Object.assign({}, target);
+  const output = Object.assign({}, target);
   if (isObject(target) && isObject(source)) {
     Object.keys(source).forEach((key) => {
       if (isObject(source[key])) {
@@ -146,7 +146,7 @@ export function getParents(elem, selector) {
 }
 
 export function getParentsUntil(elem, parent, selector) {
-  let parents = [];
+  const parents = [];
   let parentType;
   let selectorType;
   if ( parent ) {

src/editor/components/jgraduate/jQuery.jPicker.js

@@ -1652,7 +1652,7 @@ export function jPickerMethod (elem, options, commitCallback, liveCallback, canc
   let iconColor = null; // iconColor for popup icon
   let iconAlpha = null; // iconAlpha for popup icon
   let iconImage = null; // iconImage popup icon
-  let moveBar = null; // drag bar
+  const moveBar = null; // drag bar
   Object.assign(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"

src/editor/extensions/ext-foreignobject/ext-foreignobject.js

@@ -221,7 +221,7 @@ export default {
             // setSelectMode();
           });
 
-          let oldToolSourceCancel = $id('tool_source_cancel');
+          const oldToolSourceCancel = $id('tool_source_cancel');
           const toolSourceCancel = oldToolSourceCancel.cloneNode(true);
           toolSourceCancel.style.display = 'none';
           toolSourceCancel.id = 'foreign_cancel';

src/editor/extensions/ext-helloworld/ext-helloworld.js

@@ -76,7 +76,7 @@ export default {
           const y = opts.mouse_y / zoom;
 
           // We do our own formatting
-          let text = svgEditor.i18next.t(`${name}:text`, { x, y });
+          const text = svgEditor.i18next.t(`${name}:text`, { x, y });
           // Show the text using the custom alert function
           alert(text);
         }

src/editor/extensions/ext-imagelib/ext-imagelib.js

@@ -507,7 +507,7 @@ export default {
             libOpts.style.display = 'none';
             back.style.display = 'block';
           });
-          let span = document.createElement("span");
+          const span = document.createElement("span");
           span.textContent = description;
           li.appendChild(span);
         });

src/editor/extensions/ext-overview_window/dragmove/dragmove.js

@@ -4,7 +4,7 @@
 // can't use npm version as the dragmove is different.
 
 let _loaded = false;
-let _callbacks = [];
+const _callbacks = [];
 const _isTouch = window.ontouchstart !== undefined;
 
 export const dragmove = function(target, handler, parent, onStart, onEnd, onDrag) {

src/editor/extensions/ext-placemark/ext-placemark.js

@@ -104,7 +104,7 @@ export default {
       const items = txt.split(';');
       selElems.forEach((elem) => {
         if (elem && elem.getAttribute('class').includes('placemark')) {
-          let elements = elem.children;
+          const elements = elem.children;
           Array.prototype.forEach.call(elements, function(i, _){
             const [ , , type, n ] = i.id.split('_');
             if (type === 'txt') {
@@ -125,7 +125,7 @@ export default {
       font = font.join(' ');
       selElems.forEach((elem) => {
         if (elem && elem.getAttribute('class').includes('placemark')) {
-          let elements = elem.children;
+          const elements = elem.children;
           Array.prototype.forEach.call(elements, function(i, _){
             const [ , , type ] = i.id.split('_');
             if (type === 'txt') {

src/editor/extensions/ext-server_opensave/ext-php_savefile.js

@@ -23,7 +23,7 @@ export default {
         const filename = getFileNameFromTitle();
 
         // $.post(saveSvgAction, { output_svg: svg, filename });
-        let postData =  { output_svg: svg, filename };
+        const postData =  { output_svg: svg, filename };
         fetch(saveSvgAction, {
           method: "POST",
           body: JSON.stringify(postData)

src/svgcanvas/draw.js

@@ -1020,7 +1020,7 @@ export const setContext = function (elem) {
 
   // Disable other elements
   const parentsUntil = getParentsUntil(elem, '#svgcontent');
-  let siblings = [];
+  const siblings = [];
   parentsUntil.forEach(function (parent) {
     const elements = Array.prototype.filter.call(parent.parentNode.children, function(child){
       return child !== parent;

src/svgcanvas/svgcanvas.js

@@ -209,7 +209,7 @@ class SvgCanvas {
         return this._storage.has(element) && this._storage.get(element).has(key);
       },
       remove: function (element, key) {
-        let ret = this._storage.get(element).delete(key);
+        const ret = this._storage.get(element).delete(key);
         if (!this._storage.get(element).size === 0) {
           this._storage.delete(element);
         }
@@ -555,7 +555,7 @@ class SvgCanvas {
 
     const restoreRefElems = function (elem) {
       // Look for missing reference elements, restore any found
-      let attrs = {};
+      const attrs = {};
       refAttrs.forEach(function (item, _) {
         attrs[item] = elem.getAttribute(item);
       });

src/svgcanvas/utilities.js

@@ -576,7 +576,7 @@ function groupBBFix(selected) {
   let ret; let copy;
 
   if (ref) {
-    let elements = [];
+    const elements = [];
     Array.prototype.forEach.call(ref.children, function (el) {
       const elem = el.cloneNode(true);
       elem.setAttribute('visibility', 'hidden');