eslint: enforce use of const when variable not modified

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)