style(lib/core): var -> let and const codemod (#4457)

Just like #4451 but for
`lib/core`

This does add an `.eslintignore` line, perhaps we'd rather skip a file a
different way.

Smaller part of the full vision:
#4444

.eslintignore

@@ -0,0 +1,12 @@
+**/node_modules/*
+**/tmp/*
+
+build/tasks/aria-supported.js
+
+doc/api/*
+doc/examples/jest_react/*.js
+
+lib/core/imports/*.js
+lib/core/utils/uuid.js
+axe.js
+axe.min.js

eslint.config.js

@@ -189,6 +189,7 @@ module.exports = [
       'doc/api/*',
       'doc/examples/jest_react/*.js',
       'lib/core/imports/*.js',
+      'lib/core/utils/uuid.js',
       'axe.js',
       'axe.min.js'
     ]

lib/core/base/audit.js

@@ -183,7 +183,7 @@ export default class Audit {
    * Initializes the rules and checks
    */
   _init() {
-    var audit = getDefaultConfiguration(this.defaultConfig);
+    const audit = getDefaultConfiguration(this.defaultConfig);
     this.lang = audit.lang || 'en';
     this.reporter = audit.reporter;
     this.commands = {};
@@ -366,9 +366,9 @@ export default class Audit {
    * @param  {Mixed} options  Options object to pass into rules and/or disable rules or checks
    */
   after(results, options) {
-    var rules = this.rules;
+    const rules = this.rules;
     return results.map(ruleResult => {
-      var rule = findBy(rules, 'id', ruleResult.id);
+      const rule = findBy(rules, 'id', ruleResult.id);
       if (!rule) {
         // If you see this, you're probably running the Mocha tests with the axe extension installed
         throw new Error(
@@ -393,7 +393,7 @@ export default class Audit {
    * @return {Object}          Validated options object
    */
   normalizeOptions(options) {
-    var audit = this;
+    const audit = this;
     const tags = [];
     const ruleIds = [];
     audit.rules.forEach(rule => {
@@ -498,7 +498,7 @@ export default class Audit {
   }
   _constructHelpUrls(previous = null) {
     // TODO: es-modules-version
-    var version = (axe.version.match(/^[1-9][0-9]*\.[0-9]+/) || ['x.y'])[0];
+    const version = (axe.version.match(/^[1-9][0-9]*\.[0-9]+/) || ['x.y'])[0];
     this.rules.forEach(rule => {
       if (!this.data.rules[rule.id]) {
         this.data.rules[rule.id] = {};

lib/core/base/context/create-frame-context.js

@@ -11,7 +11,7 @@ export function createFrameContext(frame, { focusable, page }) {
 }
 
 function frameFocusable(frame) {
-  var tabIndex = frame.getAttribute('tabindex');
+  const tabIndex = frame.getAttribute('tabindex');
   if (!tabIndex) {
     return true;
   }

lib/core/base/context/normalize-context.js

@@ -159,10 +159,11 @@ function isShadowSelector(selector) {
 
 function isArrayLike(arr) {
   return (
+    // Avoid DOM weirdness
     arr &&
     typeof arr === 'object' &&
     typeof arr.length === 'number' &&
-    arr instanceof window.Node === false // Avoid DOM weirdness
+    arr instanceof window.Node === false
   );
 }
 

lib/core/base/rule.js

@@ -137,7 +137,7 @@ Rule.prototype.gather = function gather(context, options = {}) {
     performanceTimer.mark(markStart);
   }
 
-  var elements = select(this.selector, context);
+  let elements = select(this.selector, context);
   if (this.excludeHidden) {
     if (options.performanceTimer) {
       performanceTimer.mark(markHiddenStart);
@@ -173,13 +173,13 @@ Rule.prototype.runChecks = function runChecks(
   resolve,
   reject
 ) {
-  var self = this;
+  const self = this;
 
-  var checkQueue = queue();
+  const checkQueue = queue();
 
   this[type].forEach(c => {
-    var check = self._audit.checks[c.id || c];
-    var option = getCheckOption(check, self.id, options);
+    const check = self._audit.checks[c.id || c];
+    const option = getCheckOption(check, self.id, options);
     checkQueue.defer((res, rej) => {
       check.run(node, option, context, res, rej);
     });
@@ -246,7 +246,7 @@ Rule.prototype.run = function run(context, options = {}, resolve, reject) {
 
   nodes.forEach(node => {
     q.defer((resolveNode, rejectNode) => {
-      var checkQueue = queue();
+      const checkQueue = queue();
 
       ['any', 'all', 'none'].forEach(type => {
         checkQueue.defer((res, rej) => {
@@ -466,7 +466,7 @@ Rule.prototype.gatherAndMatchNodes = function gatherAndMatchNodes(
 function findAfterChecks(rule) {
   return getAllChecks(rule)
     .map(c => {
-      var check = rule._audit.checks[c.id || c];
+      const check = rule._audit.checks[c.id || c];
       return check && typeof check.after === 'function' ? check : null;
     })
     .filter(Boolean);
@@ -480,9 +480,9 @@ function findAfterChecks(rule) {
  * @return {Array}         Matching CheckResults
  */
 function findCheckResults(nodes, checkID) {
-  var checkResults = [];
+  const checkResults = [];
   nodes.forEach(nodeResult => {
-    var checks = getAllChecks(nodeResult);
+    const checks = getAllChecks(nodeResult);
     checks.forEach(checkResult => {
       if (checkResult.id === checkID) {
         checkResult.node = nodeResult.node;
@@ -500,10 +500,10 @@ function filterChecks(checks) {
 }
 
 function sanitizeNodes(result) {
-  var checkTypes = ['any', 'all', 'none'];
+  const checkTypes = ['any', 'all', 'none'];
 
-  var nodes = result.nodes.filter(detail => {
-    var length = 0;
+  let nodes = result.nodes.filter(detail => {
+    let length = 0;
     checkTypes.forEach(type => {
       detail[type] = filterChecks(detail[type]);
       length += detail[type].length;
@@ -533,13 +533,13 @@ function sanitizeNodes(result) {
  * @return {RuleResult}         The RuleResult as filtered by after functions
  */
 Rule.prototype.after = function after(result, options) {
-  var afterChecks = findAfterChecks(this);
-  var ruleID = this.id;
+  const afterChecks = findAfterChecks(this);
+  const ruleID = this.id;
   afterChecks.forEach(check => {
-    var beforeResults = findCheckResults(result.nodes, check.id);
-    var checkOption = getCheckOption(check, ruleID, options);
+    const beforeResults = findCheckResults(result.nodes, check.id);
+    const checkOption = getCheckOption(check, ruleID, options);
 
-    var afterResults = check.after(beforeResults, checkOption.options);
+    const afterResults = check.after(beforeResults, checkOption.options);
 
     if (this.reviewOnFail) {
       afterResults.forEach(checkResult => {

lib/core/imports/polyfills.js

@@ -49,11 +49,11 @@ if (typeof Object.assign !== 'function') {
         throw new TypeError('Cannot convert undefined or null to object');
       }
 
-      var output = Object(target);
-      for (var index = 1; index < arguments.length; index++) {
-        var source = arguments[index];
+      let output = Object(target);
+      for (let index = 1; index < arguments.length; index++) {
+        let source = arguments[index];
         if (source !== undefined && source !== null) {
-          for (var nextKey in source) {
+          for (let nextKey in source) {
             if (source.hasOwnProperty(nextKey)) {
               output[nextKey] = source[nextKey];
             }
@@ -74,12 +74,12 @@ if (!Array.prototype.find) {
       if (typeof predicate !== 'function') {
         throw new TypeError('predicate must be a function');
       }
-      var list = Object(this);
-      var length = list.length >>> 0;
-      var thisArg = arguments[1];
-      var value;
+      let list = Object(this);
+      let length = list.length >>> 0;
+      let thisArg = arguments[1];
+      let value;
 
-      for (var i = 0; i < length; i++) {
+      for (let i = 0; i < length; i++) {
         value = list[i];
         if (predicate.call(thisArg, value, i, list)) {
           return value;
@@ -99,11 +99,11 @@ if (!Array.prototype.findIndex) {
       if (typeof predicate !== 'function') {
         throw new TypeError('predicate must be a function');
       }
-      var list = Object(this);
-      var length = list.length >>> 0;
-      var value;
+      let list = Object(this);
+      let length = list.length >>> 0;
+      let value;
 
-      for (var i = 0; i < length; i++) {
+      for (let i = 0; i < length; i++) {
         value = list[i];
         if (predicate.call(thisArg, value, i, list)) {
           return i;
@@ -117,13 +117,13 @@ if (!Array.prototype.findIndex) {
 if (!Array.prototype.includes) {
   Object.defineProperty(Array.prototype, 'includes', {
     value: function (searchElement) {
-      var O = Object(this);
-      var len = parseInt(O.length, 10) || 0;
+      let O = Object(this);
+      let len = parseInt(O.length, 10) || 0;
       if (len === 0) {
         return false;
       }
-      var n = parseInt(arguments[1], 10) || 0;
-      var k;
+      let n = parseInt(arguments[1], 10) || 0;
+      let k;
       if (n >= 0) {
         k = n;
       } else {
@@ -132,7 +132,7 @@ if (!Array.prototype.includes) {
           k = 0;
         }
       }
-      var currentElement;
+      let currentElement;
       while (k < len) {
         currentElement = O[k];
         if (
@@ -162,11 +162,11 @@ if (!Array.prototype.some) {
         throw new TypeError();
       }
 
-      var t = Object(this);
-      var len = t.length >>> 0;
+      let t = Object(this);
+      let len = t.length >>> 0;
 
-      var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
-      for (var i = 0; i < len; i++) {
+      let thisArg = arguments.length >= 2 ? arguments[1] : void 0;
+      for (let i = 0; i < len; i++) {
         if (i in t && fun.call(thisArg, t[i], i, t)) {
           return true;
         }
@@ -199,7 +199,7 @@ if (!Array.prototype.flat) {
   Object.defineProperty(Array.prototype, 'flat', {
     configurable: true,
     value: function flat() {
-      var depth = isNaN(arguments[0]) ? 1 : Number(arguments[0]);
+      let depth = isNaN(arguments[0]) ? 1 : Number(arguments[0]);
 
       return depth
         ? Array.prototype.reduce.call(

lib/core/index.js

@@ -2,7 +2,7 @@
 /*global axeFunction, module, define */
 // exported namespace for axe
 /*eslint no-use-before-define: 0, no-unused-vars: 0*/
-var axe = axe || {};
+const axe = axe || {};
 axe.version = '<%= pkg.version %>';
 
 if (typeof define === 'function' && define.amd) {
@@ -24,7 +24,7 @@ if (typeof window.getComputedStyle === 'function') {
   window.axe = axe;
 }
 // local namespace for common functions
-var commons;
+let commons;
 
 function SupportError(error) {
   this.name = 'SupportError';

lib/core/public/cleanup.js

@@ -6,13 +6,13 @@ function cleanup(resolve, reject) {
     throw new Error('No audit configured');
   }
 
-  var q = axe.utils.queue();
+  const q = axe.utils.queue();
   // If a plugin fails it's cleanup, we still want the others to run
-  var cleanupErrors = [];
+  const cleanupErrors = [];
 
   Object.keys(axe.plugins).forEach(key => {
     q.defer(res => {
-      var rej = function rej(err) {
+      const rej = function rej(err) {
         cleanupErrors.push(err);
         res();
       };
@@ -24,7 +24,7 @@ function cleanup(resolve, reject) {
     });
   });
 
-  var flattenedTree = axe.utils.getFlattenedTree(document.body);
+  const flattenedTree = axe.utils.getFlattenedTree(document.body);
 
   axe.utils.querySelectorAll(flattenedTree, 'iframe, frame').forEach(node => {
     q.defer((res, rej) => {

lib/core/public/configure.js

@@ -3,9 +3,8 @@ import { configureStandards } from '../../standards';
 import constants from '../constants';
 
 function configure(spec) {
-  var audit;
+  const audit = axe._audit;
 
-  audit = axe._audit;
   if (!audit) {
     throw new Error('No audit configured');
   }

lib/core/public/get-rules.js

@@ -5,17 +5,17 @@
  */
 function getRules(tags) {
   tags = tags || [];
-  var matchingRules = !tags.length
+  const matchingRules = !tags.length
     ? axe._audit.rules
     : axe._audit.rules.filter(item => {
         return !!tags.filter(tag => {
           return item.tags.indexOf(tag) !== -1;
         }).length;
       });
 
-  var ruleData = axe._audit.data.rules || {};
+  const ruleData = axe._audit.data.rules || {};
   return matchingRules.map(matchingRule => {
-    var rd = ruleData[matchingRule.id] || {};
+    const rd = ruleData[matchingRule.id] || {};
     return {
       ruleId: matchingRule.id,
       description: rd.description,

lib/core/public/load.js

@@ -14,19 +14,19 @@ export default function load(audit) {
 }
 
 function runCommand(data, keepalive, callback) {
-  var resolve = callback;
-  var reject = function reject(err) {
+  const resolve = callback;
+  const reject = function reject(err) {
     if (err instanceof Error === false) {
       err = new Error(err);
     }
     callback(err);
   };
 
-  var context = (data && data.context) || {};
+  const context = (data && data.context) || {};
   if (context.hasOwnProperty('include') && !context.include.length) {
     context.include = [document];
   }
-  var options = (data && data.options) || {};
+  const options = (data && data.options) || {};
 
   switch (data.command) {
     case 'rules':

lib/core/public/plugins.js

@@ -18,8 +18,8 @@ Plugin.prototype.collect = function collect() {
 };
 
 Plugin.prototype.cleanup = function cleanup(done) {
-  var q = axe.utils.queue();
-  var that = this;
+  const q = axe.utils.queue();
+  const that = this;
   Object.keys(this._registry).forEach(key => {
     q.defer(_done => {
       that._registry[key].cleanup(_done);

lib/core/public/reset.js

@@ -1,7 +1,7 @@
 import { resetStandards } from '../../standards';
 
 function reset() {
-  var audit = axe._audit;
+  const audit = axe._audit;
 
   if (!audit) {
     throw new Error('No audit configured');