From 1b101f09eeafacba5babe715a5b32724cb0741dc Mon Sep 17 00:00:00 2001
From: Ed Sanders <esanders@wikimedia.org>
Date: Fri, 14 Jun 2024 12:53:32 +0100
Subject: [PATCH] ESLint: Update syntax to ES6 and autofix

Change-Id: I613cc64a9bf3f375a40f75a1441b83f181a2ab42
---
 resources/.eslintrc.json                      |  4 +-
 resources/addon/edit/matchbrackets-wmde.js    | 10 ++--
 resources/ext.CodeMirror.WikiEditor.js        | 48 ++++++++--------
 resources/ext.CodeMirror.js                   |  2 +-
 resources/mode/mediawiki/mediawiki.js         | 56 +++++++++----------
 .../tests/qunit/CodeMirror.mediawiki.test.js  | 38 ++++++-------
 .../modules/ve-cm/ve.ui.CodeMirrorAction.js   | 48 ++++++++--------
 .../modules/ve-cm/ve.ui.CodeMirrorTool.js     | 38 +++++++------
 8 files changed, 121 insertions(+), 123 deletions(-)

diff --git a/resources/.eslintrc.json b/resources/.eslintrc.json
index 67b06a90..51c09995 100644
--- a/resources/.eslintrc.json
+++ b/resources/.eslintrc.json
@@ -1,7 +1,7 @@
 {
 	"root": true,
 	"extends": [
-		"wikimedia/client-es5",
+		"wikimedia/client",
 		"wikimedia/jquery",
 		"wikimedia/mediawiki"
 	],
@@ -13,7 +13,7 @@
 	},
 	"rules": {
 		"max-len": "off",
-		"es-x/no-object-assign": "warn"
+		"prefer-const": "warn"
 	},
 	"overrides": [
 		{
diff --git a/resources/addon/edit/matchbrackets-wmde.js b/resources/addon/edit/matchbrackets-wmde.js
index a50c03da..0497d01d 100644
--- a/resources/addon/edit/matchbrackets-wmde.js
+++ b/resources/addon/edit/matchbrackets-wmde.js
@@ -37,7 +37,7 @@
   }
 
   /* eslint-enable */
-  var surroundingBrackets = {
+  const surroundingBrackets = {
     '(': ')',
     ')': false,
     '[': ']',
@@ -47,7 +47,7 @@
   };
 
   function findSurroundingBrackets( cm, where, config ) {
-    var from, to, ch,
+    let from, to, ch,
       nestedBracketsToSkip = 0,
       lineNo = where.line,
       line = cm.getLine( lineNo ),
@@ -140,13 +140,13 @@
   }
 
   function stillTheSameMarks( marks, config ) {
-    var same = config.currentMarks &&
+    const same = config.currentMarks &&
       // No need to compare the details if it's not even the same amount
       config.currentMarks.length === marks.length &&
       // We need the flexibility because the order can be closing → opening bracket as well
-      marks.every( function ( mark ) {
+      marks.every( ( mark ) => {
         // These are typically only 2 elements for the opening and closing bracket
-        for ( var i = 0; i < config.currentMarks.length; i++ ) {
+        for ( let i = 0; i < config.currentMarks.length; i++ ) {
           // Ordered from "most likely to change" to "least likely" for performance
           if ( config.currentMarks[i].from.ch === mark.from.ch &&
             config.currentMarks[i].from.line === mark.from.line &&
diff --git a/resources/ext.CodeMirror.WikiEditor.js b/resources/ext.CodeMirror.WikiEditor.js
index 2ea45820..980cfefd 100644
--- a/resources/ext.CodeMirror.WikiEditor.js
+++ b/resources/ext.CodeMirror.WikiEditor.js
@@ -1,10 +1,10 @@
 function init() {
-	var extCodeMirror = require( 'ext.CodeMirror' );
-	var codeMirror, $textbox1, realtimePreviewHandler;
+	const extCodeMirror = require( 'ext.CodeMirror' );
+	let codeMirror, $textbox1, realtimePreviewHandler;
 
-	var useCodeMirror = mw.user.options.get( 'usecodemirror' ) > 0;
+	let useCodeMirror = mw.user.options.get( 'usecodemirror' ) > 0;
 
-	var originHooksTextarea = $.valHooks.textarea;
+	const originHooksTextarea = $.valHooks.textarea;
 	// define jQuery hook for searching and replacing text using JS if CodeMirror is enabled, see Bug: T108711
 	$.valHooks.textarea = {
 		get: function ( elem ) {
@@ -27,7 +27,7 @@ function init() {
 
 	// jQuery.textSelection overrides for CodeMirror.
 	// See jQuery.textSelection.js for method documentation
-	var cmTextSelection = {
+	const cmTextSelection = {
 		getContents: function () {
 			return codeMirror.doc.getValue();
 		},
@@ -51,7 +51,7 @@ function init() {
 			return this;
 		},
 		getCaretPosition: function ( options ) {
-			var caretPos = codeMirror.doc.indexFromPos( codeMirror.doc.getCursor( true ) ),
+			const caretPos = codeMirror.doc.indexFromPos( codeMirror.doc.getCursor( true ) ),
 				endPos = codeMirror.doc.indexFromPos( codeMirror.doc.getCursor( false ) );
 			if ( options.startAndEnd ) {
 				return [ caretPos, endPos ];
@@ -83,14 +83,14 @@ function init() {
 			return false;
 		}
 
-		var namespaces = mw.config.get( 'wgCodeMirrorLineNumberingNamespaces' );
+		const namespaces = mw.config.get( 'wgCodeMirrorLineNumberingNamespaces' );
 		// Set to [] to disable everywhere, or null to enable everywhere
 		return !namespaces ||
 			namespaces.indexOf( mw.config.get( 'wgNamespaceNumber' ) ) !== -1;
 	}
 
 	// Keep these modules in sync with MediaWiki\Extension\CodeMirror\Hooks.php
-	var codeMirrorCoreModules = [
+	const codeMirrorCoreModules = [
 		'ext.CodeMirror.lib',
 		'ext.CodeMirror.mode.mediawiki'
 	];
@@ -100,15 +100,15 @@ function init() {
 	 * and react to changes coming from WikiEditor (including Realtime Preview if its enabled).
 	 */
 	function setupSizing() {
-		var $codeMirror = $( codeMirror.getWrapperElement() );
+		const $codeMirror = $( codeMirror.getWrapperElement() );
 
 		// Only add resizing corner if realtime preview is enabled,
 		// because that feature provides height resizing (even when preview isn't used).
 		if ( mw.loader.getState( 'ext.wikiEditor.realtimepreview' ) === 'ready' ) {
 			codeMirror.setSize( '100%', $textbox1.parent().height() );
 		}
-		var $resizableHandle = $codeMirror.find( '.ui-resizable-handle' );
-		mw.hook( 'ext.WikiEditor.realtimepreview.enable' ).add( function ( realtimePreview ) {
+		const $resizableHandle = $codeMirror.find( '.ui-resizable-handle' );
+		mw.hook( 'ext.WikiEditor.realtimepreview.enable' ).add( ( realtimePreview ) => {
 			// CodeMirror may have been turned on and then off again before realtimepreview is enabled, in which case it will be null.
 			if ( !codeMirror ) {
 				return;
@@ -121,7 +121,7 @@ function init() {
 			// Fix the width and height of the CodeMirror area.
 			codeMirror.setSize( '100%', realtimePreview.twoPaneLayout.$element.height() );
 		} );
-		mw.hook( 'ext.WikiEditor.realtimepreview.resize' ).add( function ( resizingBar ) {
+		mw.hook( 'ext.WikiEditor.realtimepreview.resize' ).add( ( resizingBar ) => {
 			// CodeMirror may have been turned off after realtimepreview was opened, in which case it will be null.
 			if ( !codeMirror ) {
 				return;
@@ -129,7 +129,7 @@ function init() {
 			// Keep in sync with the height of the pane.
 			codeMirror.setSize( '100%', resizingBar.getResizedPane().height() );
 		} );
-		mw.hook( 'ext.WikiEditor.realtimepreview.disable' ).add( function () {
+		mw.hook( 'ext.WikiEditor.realtimepreview.disable' ).add( () => {
 			// Re-show the corner resize handle.
 			$resizableHandle.show();
 			// CodeMirror may have been turned off after realtimepreview was opened, in which case it will be null.
@@ -145,10 +145,10 @@ function init() {
 	 * Replaces the default textarea with CodeMirror
 	 */
 	function enableCodeMirror() {
-		var config = mw.config.get( 'extCodeMirrorConfig' );
+		const config = mw.config.get( 'extCodeMirrorConfig' );
 
-		mw.loader.using( codeMirrorCoreModules.concat( config.pluginModules ), function () {
-			var $codeMirror, cmOptions,
+		mw.loader.using( codeMirrorCoreModules.concat( config.pluginModules ), () => {
+			let $codeMirror, cmOptions,
 				selectionStart = $textbox1.prop( 'selectionStart' ),
 				selectionEnd = $textbox1.prop( 'selectionEnd' ),
 				scrollTop = $textbox1.scrollTop(),
@@ -192,13 +192,13 @@ function init() {
 			codeMirror = CodeMirror.fromTextArea( $textbox1[ 0 ], cmOptions );
 			$codeMirror = $( codeMirror.getWrapperElement() );
 
-			codeMirror.on( 'focus', function () {
+			codeMirror.on( 'focus', () => {
 				$textbox1.triggerHandler( 'focus' );
 			} );
-			codeMirror.on( 'blur', function () {
+			codeMirror.on( 'blur', () => {
 				$textbox1.triggerHandler( 'blur' );
 			} );
-			mw.hook( 'editRecovery.loadEnd' ).add( function ( data ) {
+			mw.hook( 'editRecovery.loadEnd' ).add( ( data ) => {
 				codeMirror.on( 'change', data.fieldChangeHandler );
 			} );
 
@@ -250,7 +250,7 @@ function init() {
 	 */
 	function updateToolbarButton() {
 		// eslint-disable-next-line no-jquery/no-global-selector
-		var $button = $( '#mw-editbutton-codemirror' );
+		const $button = $( '#mw-editbutton-codemirror' );
 
 		$button.toggleClass( 'mw-editbutton-codemirror-active', !!useCodeMirror );
 
@@ -264,7 +264,7 @@ function init() {
 	 * Enables or disables CodeMirror
 	 */
 	function switchCodeMirror() {
-		var selectionObj, selectionStart, selectionEnd, scrollTop, hasFocus, $codeMirror;
+		let selectionObj, selectionStart, selectionEnd, scrollTop, hasFocus, $codeMirror;
 
 		if ( codeMirror ) {
 			scrollTop = codeMirror.getScrollInfo().top;
@@ -305,7 +305,7 @@ function init() {
 	 * Adds the CodeMirror button to WikiEditor
 	 */
 	function addCodeMirrorToWikiEditor() {
-		var $codeMirrorButton,
+		let $codeMirrorButton,
 			context = $textbox1.data( 'wikiEditor-context' ),
 			toolbar = context && context.modules && context.modules.toolbar;
 
@@ -357,13 +357,13 @@ function init() {
 	}
 
 	// Add CodeMirror button to the enhanced editing toolbar.
-	mw.hook( 'wikiEditor.toolbarReady' ).add( function ( $textarea ) {
+	mw.hook( 'wikiEditor.toolbarReady' ).add( ( $textarea ) => {
 		$textbox1 = $textarea;
 		addCodeMirrorToWikiEditor();
 	} );
 
 	// Synchronize textarea with CodeMirror before leaving
-	window.addEventListener( 'beforeunload', function () {
+	window.addEventListener( 'beforeunload', () => {
 		if ( codeMirror ) {
 			codeMirror.save();
 		}
diff --git a/resources/ext.CodeMirror.js b/resources/ext.CodeMirror.js
index 68bfcd7e..1218e2bf 100644
--- a/resources/ext.CodeMirror.js
+++ b/resources/ext.CodeMirror.js
@@ -6,7 +6,7 @@ require( './ext.CodeMirror.data.js' );
  * @param {Object} data
  */
 function logUsage( data ) {
-	var event, editCountBucket;
+	let event, editCountBucket;
 
 	/* eslint-disable camelcase */
 	event = Object.assign( {
diff --git a/resources/mode/mediawiki/mediawiki.js b/resources/mode/mediawiki/mediawiki.js
index 7cf95f5f..c7c06f23 100644
--- a/resources/mode/mediawiki/mediawiki.js
+++ b/resources/mode/mediawiki/mediawiki.js
@@ -2,7 +2,7 @@
 	'use strict';
 
 	function eatMnemonic( stream, style, mnemonicStyle ) {
-		var ok;
+		let ok;
 		if ( stream.eat( '#' ) ) {
 			if ( stream.eat( 'x' ) ) {
 				ok = stream.eatWhile( /[a-fA-F\d]/ ) && stream.eat( ';' );
@@ -19,9 +19,9 @@
 		return style;
 	}
 
-	CodeMirror.defineMode( 'mediawiki', function ( config /* , parserConfig */ ) {
+	CodeMirror.defineMode( 'mediawiki', ( config /* , parserConfig */ ) => {
 
-		var mwConfig = config.mwConfig,
+		let mwConfig = config.mwConfig,
 
 			urlProtocols = new RegExp( '^(?:' + mwConfig.urlProtocols + ')', 'i' ),
 			permittedHtmlTags = { b: true, bdi: true, del: true, i: true, ins: true,
@@ -49,7 +49,7 @@
 		}
 
 		function makeLocalStyle( style, state, endGround ) {
-			var ground = '';
+			let ground = '';
 			switch ( state.nTemplate ) {
 				case 0:
 					break;
@@ -363,9 +363,9 @@
 		}
 
 		function eatLinkText() {
-			var linkIsBold, linkIsItalic;
+			let linkIsBold, linkIsItalic;
 			return function ( stream, state ) {
-				var tmpstyle;
+				let tmpstyle;
 				if ( stream.match( ']]' ) ) {
 					state.tokenize = state.stack.pop();
 					return makeLocalStyle( 'mw-link-bracket', state, 'nLink' );
@@ -394,7 +394,7 @@
 
 		function eatTagName( chars, isCloseTag, isHtmlTag ) {
 			return function ( stream, state ) {
-				var name = '';
+				let name = '';
 				while ( chars > 0 ) {
 					chars--;
 					name = name + stream.next();
@@ -464,7 +464,7 @@
 
 		function eatExtTagArea( name ) {
 			return function ( stream, state ) {
-				var origString = false,
+				let origString = false,
 					from = stream.pos,
 					to,
 
@@ -503,7 +503,7 @@
 
 		function eatExtTokens( origString ) {
 			return function ( stream, state ) {
-				var ret;
+				let ret;
 				if ( state.extMode === false ) {
 					ret = ( origString === false && stream.sol() ? 'line-cm-mw-exttag' : 'mw-exttag' );
 					stream.skipToEnd();
@@ -634,7 +634,7 @@
 
 		function eatWikiText( style, mnemonicStyle ) {
 			return function ( stream, state ) {
-				var ch, tmp, mt, name, isCloseTag, tagname,
+				let ch, tmp, mt, name, isCloseTag, tagname,
 					sol = stream.sol();
 
 				function chain( parser ) {
@@ -870,7 +870,7 @@
 			// firstsingleletterword has maximum priority
 			// firstmultiletterword has medium priority
 			// firstspace has low priority
-			var end = stream.pos,
+			const end = stream.pos,
 				str = stream.string.slice( 0, end - 3 ),
 				x1 = str.slice( -1, -1 + 1 ),
 				x2 = str.slice( -2, -2 + 1 );
@@ -911,7 +911,7 @@
 				};
 			},
 			token: function ( stream, state ) {
-				var style, p, t, f,
+				let style, p, t, f,
 					readyTokens = [],
 					tmpTokens = [];
 
@@ -975,7 +975,7 @@
 				return t.style;
 			},
 			blankLine: function ( state ) {
-				var ret;
+				let ret;
 				if ( state.extName ) {
 					if ( state.extMode ) {
 						ret = '';
@@ -994,7 +994,7 @@
 
 	function eatNowiki( style, lineStyle ) {
 		return function ( stream, state, ownLine ) {
-			var s;
+			let s;
 			if ( ownLine && stream.sol() ) {
 				state.ownLine = true;
 			} else if ( ownLine === false && state.ownLine ) {
@@ -1009,22 +1009,18 @@
 		};
 	}
 
-	CodeMirror.defineMode( 'mw-tag-pre', function ( /* config, parserConfig */ ) {
-		return {
-			startState: function () {
-				return {};
-			},
-			token: eatNowiki( 'mw-tag-pre', 'line-cm-mw-tag-pre' )
-		};
-	} );
+	CodeMirror.defineMode( 'mw-tag-pre', ( /* config, parserConfig */ ) => ( {
+		startState: function () {
+			return {};
+		},
+		token: eatNowiki( 'mw-tag-pre', 'line-cm-mw-tag-pre' )
+	} ) );
 
-	CodeMirror.defineMode( 'mw-tag-nowiki', function ( /* config, parserConfig */ ) {
-		return {
-			startState: function () {
-				return {};
-			},
-			token: eatNowiki( 'mw-tag-nowiki', 'line-cm-mw-tag-nowiki' )
-		};
-	} );
+	CodeMirror.defineMode( 'mw-tag-nowiki', ( /* config, parserConfig */ ) => ( {
+		startState: function () {
+			return {};
+		},
+		token: eatNowiki( 'mw-tag-nowiki', 'line-cm-mw-tag-nowiki' )
+	} ) );
 
 }( CodeMirror ) );
diff --git a/resources/mode/mediawiki/tests/qunit/CodeMirror.mediawiki.test.js b/resources/mode/mediawiki/tests/qunit/CodeMirror.mediawiki.test.js
index cc035540..c45f7468 100644
--- a/resources/mode/mediawiki/tests/qunit/CodeMirror.mediawiki.test.js
+++ b/resources/mode/mediawiki/tests/qunit/CodeMirror.mediawiki.test.js
@@ -8,7 +8,7 @@
 	 *
 	 * @type {Object}
 	 */
-	var config = mw.config.get( 'extCodeMirrorConfig' ),
+	const config = mw.config.get( 'extCodeMirrorConfig' ),
 		extCiteLoaded = config.tagModes.ref,
 		testCases = [
 			{
@@ -146,7 +146,7 @@
 	 * @param {Function} callback Ran after CodeMirror has been initialized.
 	 */
 	function setup( wikitext, callback ) {
-		var $textarea = $( '<textarea>' );
+		const $textarea = $( '<textarea>' );
 
 		$textarea.val( wikitext );
 		$( '#qunit-fixture' ).append( $textarea );
@@ -167,24 +167,22 @@
 		$( '#qunit-fixture' ).find( '.CodeMirror' ).remove();
 	}
 
-	testCases.forEach( function ( testCase ) {
-		QUnit.test( 'Syntax highlighting: ' + testCase.title, function ( assert ) {
-			return mw.loader.using( config.pluginModules ).then( function () {
-				setup( testCase.input, function () {
-					var html = $( '.CodeMirror-code' ).html()
-						// CodeMirror does this only on WebKit browsers. Strip it to ensure tests
-						// pass across all browsers.
-						.replace( / style="padding-right: 0\.1px;"/g, '' )
-						// Reduce noise we don't really care about to make tests more readable.
-						.replace( / role="presentation"/g, '' )
-						.replace( / class="\s*CodeMirror-line\s*"/g, '' );
-					assert.strictEqual(
-						html,
-						testCase.output,
-						'Textarea contents'
-					);
-				} );
+	testCases.forEach( ( testCase ) => {
+		QUnit.test( 'Syntax highlighting: ' + testCase.title, ( assert ) => mw.loader.using( config.pluginModules ).then( () => {
+			setup( testCase.input, () => {
+				const html = $( '.CodeMirror-code' ).html()
+				// CodeMirror does this only on WebKit browsers. Strip it to ensure tests
+				// pass across all browsers.
+					.replace( / style="padding-right: 0\.1px;"/g, '' )
+				// Reduce noise we don't really care about to make tests more readable.
+					.replace( / role="presentation"/g, '' )
+					.replace( / class="\s*CodeMirror-line\s*"/g, '' );
+				assert.strictEqual(
+					html,
+					testCase.output,
+					'Textarea contents'
+				);
 			} );
-		} );
+		} ) );
 	} );
 }() );
diff --git a/resources/modules/ve-cm/ve.ui.CodeMirrorAction.js b/resources/modules/ve-cm/ve.ui.CodeMirrorAction.js
index 2679e90b..f84bb3bc 100644
--- a/resources/modules/ve-cm/ve.ui.CodeMirrorAction.js
+++ b/resources/modules/ve-cm/ve.ui.CodeMirrorAction.js
@@ -39,7 +39,7 @@ ve.ui.CodeMirrorAction.static.isLineNumbering = function () {
 		return false;
 	}
 
-	var namespaces = mw.config.get( 'wgCodeMirrorLineNumberingNamespaces' );
+	const namespaces = mw.config.get( 'wgCodeMirrorLineNumberingNamespaces' );
 	// Set to [] to disable everywhere, or null to enable everywhere
 	return !namespaces ||
 		namespaces.indexOf( mw.config.get( 'wgNamespaceNumber' ) ) !== -1;
@@ -51,7 +51,7 @@ ve.ui.CodeMirrorAction.static.isLineNumbering = function () {
  * @return {boolean} Action was executed
  */
 ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
-	var action = this,
+	const action = this,
 		surface = this.surface,
 		surfaceView = surface.getView(),
 		doc = surface.getModel().getDocument();
@@ -62,20 +62,20 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
 			'ext.CodeMirror.lib',
 			'ext.CodeMirror.mode.mediawiki',
 			'jquery.client'
-		] ).then( function () {
-			var config = mw.config.get( 'extCodeMirrorConfig' );
+		] ).then( () => {
+			const config = mw.config.get( 'extCodeMirrorConfig' );
 
 			if ( !surface.mirror ) {
 				// Action was toggled to false since promise started
 				return;
 			}
-			mw.loader.using( config.pluginModules, function () {
+			mw.loader.using( config.pluginModules, () => {
 				if ( !surface.mirror ) {
 					// Action was toggled to false since promise started
 					return;
 				}
-				var tabSizeValue = surfaceView.documentView.documentNode.$element.css( 'tab-size' );
-				var cmOptions = {
+				const tabSizeValue = surfaceView.documentView.documentNode.$element.css( 'tab-size' );
+				const cmOptions = {
 					value: surface.getDom(),
 					mwConfig: config,
 					readOnly: 'nocursor',
@@ -120,8 +120,8 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
 					surfaceView.$element.addClass( 'cm-mw-colorblind-colors' );
 				}
 
-				var profile = $.client.profile();
-				var supportsTransparentText = 'WebkitTextFillColor' in document.body.style &&
+				const profile = $.client.profile();
+				const supportsTransparentText = 'WebkitTextFillColor' in document.body.style &&
 					// Disable on Firefox+OSX (T175223)
 					!( profile.layout === 'gecko' && profile.platform === 'mac' );
 
@@ -133,7 +133,7 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
 
 				if ( cmOptions.lineNumbers ) {
 					// Transfer gutter width to VE overlay.
-					var updateGutter = function ( cmDisplay ) {
+					const updateGutter = function ( cmDisplay ) {
 						surfaceView.$documentNode.css( 'margin-left', cmDisplay.gutters.offsetWidth );
 					};
 					CodeMirror.on( surface.mirror.display, 'updateGutter', updateGutter );
@@ -154,7 +154,7 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
 
 				action.onLangChange();
 
-				ve.init.target.once( 'surfaceReady', function () {
+				ve.init.target.once( 'surfaceReady', () => {
 					if ( surface.mirror ) {
 						surface.mirror.refresh();
 					}
@@ -177,7 +177,7 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
 			// Reset gutter.
 			surfaceView.$documentNode.css( 'margin-left', '' );
 
-			var mirrorElement = surface.mirror.getWrapperElement();
+			const mirrorElement = surface.mirror.getWrapperElement();
 			mirrorElement.parentNode.removeChild( mirrorElement );
 		}
 
@@ -193,7 +193,7 @@ ve.ui.CodeMirrorAction.prototype.toggle = function ( enable ) {
  * @param {ve.dm.Selection} selection
  */
 ve.ui.CodeMirrorAction.prototype.onSelect = function ( selection ) {
-	var range = selection.getCoveringRange();
+	const range = selection.getCoveringRange();
 
 	// Do not re-trigger bracket matching as long as something is selected
 	if ( !range || !range.isCollapsed() ) {
@@ -207,7 +207,7 @@ ve.ui.CodeMirrorAction.prototype.onSelect = function ( selection ) {
  * Handle langChange events from the document view
  */
 ve.ui.CodeMirrorAction.prototype.onLangChange = function () {
-	var surface = this.surface,
+	const surface = this.surface,
 		doc = surface.getView().getDocument(),
 		dir = doc.getDir(), lang = doc.getLang();
 
@@ -226,13 +226,13 @@ ve.ui.CodeMirrorAction.prototype.onLangChange = function () {
  * @param {ve.dm.Transaction} tx
  */
 ve.ui.CodeMirrorAction.prototype.onDocumentPrecommit = function ( tx ) {
-	var offset = 0,
+	let offset = 0,
 		replacements = [],
 		action = this,
 		store = this.surface.getModel().getDocument().getStore(),
 		mirror = this.surface.mirror;
 
-	tx.operations.forEach( function ( op ) {
+	tx.operations.forEach( ( op ) => {
 		if ( op.type === 'retain' ) {
 			offset += op.length;
 		} else if ( op.type === 'replace' ) {
@@ -247,7 +247,7 @@ ve.ui.CodeMirrorAction.prototype.onDocumentPrecommit = function ( tx ) {
 	} );
 
 	// Apply replacements in reverse to avoid having to shift offsets
-	for ( var i = replacements.length - 1; i >= 0; i-- ) {
+	for ( let i = replacements.length - 1; i >= 0; i-- ) {
 		mirror.replaceRange(
 			replacements[ i ].data,
 			replacements[ i ].start,
@@ -277,11 +277,13 @@ ve.ui.CodeMirrorAction.prototype.getPosFromOffset = function ( veOffset ) {
 
 /* Registration */
 
-// eslint-disable-next-line no-jquery/no-global-selector
-var contentDir = $( '.mw-body-content .mw-parser-output' ).attr( 'dir' ) ||
-	// New pages will use wgPageContentLanguage which is set on the html element.
-	document.documentElement.dir;
+{
+	// eslint-disable-next-line no-jquery/no-global-selector
+	const contentDir = $( '.mw-body-content .mw-parser-output' ).attr( 'dir' ) ||
+		// New pages will use wgPageContentLanguage which is set on the html element.
+		document.documentElement.dir;
 
-if ( contentDir === 'ltr' ) {
-	ve.ui.actionFactory.register( ve.ui.CodeMirrorAction );
+	if ( contentDir === 'ltr' ) {
+		ve.ui.actionFactory.register( ve.ui.CodeMirrorAction );
+	}
 }
diff --git a/resources/modules/ve-cm/ve.ui.CodeMirrorTool.js b/resources/modules/ve-cm/ve.ui.CodeMirrorTool.js
index f3e42b18..7e8b71c9 100644
--- a/resources/modules/ve-cm/ve.ui.CodeMirrorTool.js
+++ b/resources/modules/ve-cm/ve.ui.CodeMirrorTool.js
@@ -39,7 +39,7 @@ ve.ui.CodeMirrorTool.prototype.onSelect = function () {
 	// Parent method
 	ve.ui.CodeMirrorTool.super.prototype.onSelect.apply( this, arguments );
 
-	var useCodeMirror = !!this.toolbar.surface.mirror;
+	const useCodeMirror = !!this.toolbar.surface.mirror;
 	this.setActive( useCodeMirror );
 
 	new mw.Api().saveOption( 'usecodemirror', useCodeMirror ? 1 : 0 );
@@ -58,13 +58,13 @@ ve.ui.CodeMirrorTool.prototype.onSelect = function () {
  * @inheritdoc
  */
 ve.ui.CodeMirrorTool.prototype.onSurfaceChange = function ( oldSurface, newSurface ) {
-	var isDisabled = newSurface.getMode() !== 'source';
+	const isDisabled = newSurface.getMode() !== 'source';
 
 	this.setDisabled( isDisabled );
 	if ( !isDisabled ) {
-		var command = this.getCommand();
-		var surface = this.toolbar.getSurface();
-		var useCodeMirror = mw.user.options.get( 'usecodemirror' ) > 0;
+		const command = this.getCommand();
+		const surface = this.toolbar.getSurface();
+		const useCodeMirror = mw.user.options.get( 'usecodemirror' ) > 0;
 		command.execute( surface, [ useCodeMirror ] );
 		this.setActive( useCodeMirror );
 
@@ -82,19 +82,21 @@ ve.ui.CodeMirrorTool.prototype.onSurfaceChange = function ( oldSurface, newSurfa
 
 ve.ui.CodeMirrorTool.prototype.onUpdateState = function () {};
 
-// eslint-disable-next-line no-jquery/no-global-selector
-var contentDir = $( '.mw-body-content .mw-parser-output' ).attr( 'dir' ) ||
-	// New pages will use wgPageContentLanguage which is set on the html element.
-	document.documentElement.dir;
+{
+	// eslint-disable-next-line no-jquery/no-global-selector
+	const contentDir = $( '.mw-body-content .mw-parser-output' ).attr( 'dir' ) ||
+		// New pages will use wgPageContentLanguage which is set on the html element.
+		document.documentElement.dir;
 
-if ( contentDir === 'ltr' ) {
-	/* Registration */
-	ve.ui.toolFactory.register( ve.ui.CodeMirrorTool );
+	if ( contentDir === 'ltr' ) {
+		/* Registration */
+		ve.ui.toolFactory.register( ve.ui.CodeMirrorTool );
 
-	/* Command */
-	ve.ui.commandRegistry.register(
-		new ve.ui.Command(
-			'codeMirror', 'codeMirror', 'toggle'
-		)
-	);
+		/* Command */
+		ve.ui.commandRegistry.register(
+			new ve.ui.Command(
+				'codeMirror', 'codeMirror', 'toggle'
+			)
+		);
+	}
 }