Added ESLint with minimal config (#2831)

.eslintrc.js

@@ -0,0 +1,122 @@
+/** @type {import('eslint').Linter.Config} */
+module.exports = {
+	extends: 'eslint:recommended',
+	rules: {
+		// I turned this rule off because we use `hasOwnProperty` in a lot of places
+		// TODO: Think about re-enabling this rule
+		'no-prototype-builtins': 'off',
+		// TODO: Think about re-enabling this rule
+		'no-cond-assign': 'off',
+		// TODO: Think about re-enabling this rule
+		'no-inner-declarations': 'off',
+		// TODO: Think about re-enabling this rule
+		'no-sparse-arrays': 'off',
+
+		// turning off some regex rules
+		// these are supposed to protect against accidental use but we need those quite often
+		'no-control-regex': 'off',
+		'no-empty-character-class': 'off',
+		'no-useless-escape': 'off'
+	},
+	ignorePatterns: [
+		'*.min.js',
+		'vendor/',
+		'utopia.js',
+		'docs/',
+		'components.js',
+		'prism.js',
+		'node_modules'
+	],
+
+	overrides: [
+		{
+			// Languages and plugins
+			files: [
+				'components/*.js',
+				'plugins/*/prism-*.js'
+			],
+			excludedFiles: 'components/index.js',
+			env: {
+				browser: true,
+				node: true,
+				worker: true
+			},
+			globals: {
+				'Prism': true
+			}
+		},
+		{
+			// `loadLanguages` function for Node.js
+			files: 'components/index.js',
+			env: {
+				es6: true,
+				node: true
+			},
+			parserOptions: {
+				ecmaVersion: 6
+			},
+			globals: {
+				'Prism': true
+			}
+		},
+		{
+			// Gulp and Danger
+			files: 'dependencies.js',
+			env: {
+				browser: true,
+				node: true
+			}
+		},
+		{
+			// The scripts that run on our website
+			files: 'assets/*.js',
+			env: {
+				browser: true
+			},
+			globals: {
+				'components': true,
+				'getLoader': true,
+				'PrefixFree': true,
+				'Prism': true,
+				'Promise': true,
+				'saveAs': true,
+				'$': true,
+				'$$': true,
+				'$u': true
+			}
+		},
+		{
+			// Test files
+			files: 'tests/**',
+			env: {
+				es6: true,
+				mocha: true,
+				node: true
+			},
+			parserOptions: {
+				ecmaVersion: 2018
+			}
+		},
+		{
+			// Gulp and Danger
+			files: [
+				'gulpfile.js/**',
+				'dangerfile.js'
+			],
+			env: {
+				es6: true,
+				node: true
+			},
+			parserOptions: {
+				ecmaVersion: 2018
+			}
+		},
+		{
+			// This file
+			files: '.eslintrc.js',
+			env: {
+				node: true
+			}
+		},
+	]
+};

.github/workflows/test.yml

@@ -44,3 +44,16 @@ jobs:
           git add --all && \
           git diff-index --cached HEAD --stat --exit-code || \
           (echo && echo "The above files changed because the build is not up to date." && echo "Please rebuild Prism." && exit 1)
+
+  lint:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js 14.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 14.x
+      - run: npm ci
+      - run: npm run lint

.npmignore

@@ -19,3 +19,4 @@ gulpfile.js
 .editorconfig
 .gitattributes
 .travis.yml
+.eslintrc.js

assets/code.js

@@ -11,9 +11,9 @@ $$('[data-plugin-header]').forEach(function (element) {
 });
 
 $$('[data-src][data-type="text/html"]').forEach(function(element) {
-	var src = element.getAttribute('data-src'),
-	    html = element.getAttribute('data-type') === 'text/html',
-	    contentProperty = html ? 'innerHTML' : 'textContent';
+	var src = element.getAttribute('data-src');
+	var html = element.getAttribute('data-type') === 'text/html';
+	var contentProperty = html ? 'innerHTML' : 'textContent';
 
 	$u.xhr({
 		url: src,
@@ -24,12 +24,12 @@ $$('[data-src][data-type="text/html"]').forEach(function(element) {
 				// Run JS
 
 				$$('script', element).forEach(function (script) {
-					var after = script.nextSibling, parent = script.parentNode;
+					var parent = script.parentNode;
 					parent.removeChild(script);
 					document.head.appendChild(script);
 				});
 			}
-			catch (e) {}
+			catch (e) { /* noop */ }
 		}
 	});
 });
@@ -43,9 +43,9 @@ $$('[data-src][data-type="text/html"]').forEach(function(element) {
 var toc = document.createElement('ol');
 
 $$('body > section > h1').forEach(function(h1) {
-	var section = h1.parentNode,
-	    text = h1.textContent,
-	    id = h1.id || section.id;
+	var section = h1.parentNode;
+	var text = h1.textContent;
+	var id = h1.id || section.id;
 
 	// Assign id if one does not exist
 	if (!id) {
@@ -128,8 +128,8 @@ if (toc.children.length > 0) {
 
 		if(!style.width) {
 			// calc not supported
-			var header = $('header'),
-			    footer = $('footer');
+			var header = $('header');
+			var footer = $('footer');
 
 			function calculatePadding() {
 				header.style.padding =

assets/download.js

@@ -40,9 +40,9 @@ function toArray(value) {
 var hstr = window.location.hash.match(/(?:languages|plugins)=[-+\w]+|themes=[-\w]+/g);
 if (hstr) {
 	hstr.forEach(function(str) {
-		var kv = str.split('=', 2),
-		    category = kv[0],
-		    ids = kv[1].split('+');
+		var kv = str.split('=', 2);
+		var category = kv[0];
+		var ids = kv[1].split('+');
 		if (category !== 'meta' && category !== 'core' && components[category]) {
 			for (var id in components[category]) {
 				if (components[category][id].option) {
@@ -54,6 +54,7 @@ if (hstr) {
 				if (themeInput) {
 					themeInput.checked = true;
 				}
+				// eslint-disable-next-line no-undef
 				setTheme(ids[0]);
 			}
 			var makeDefault = function (id) {
@@ -314,8 +315,8 @@ function getFilesSizes() {
 				continue;
 			}
 
-			var distro = all[id].files[minified? 'minified' : 'dev'],
-			    files = distro.paths;
+			var distro = all[id].files[minified? 'minified' : 'dev'];
+			var files = distro.paths;
 
 			files.forEach(function (filepath) {
 				var file = cache[filepath] = cache[filepath] || {};
@@ -380,8 +381,8 @@ function update(updatedCategory, updatedId){
 					if (cache[path]) {
 						var file = cache[path];
 
-						var type = path.match(/\.(\w+)$/)[1],
-						    size = file.size || 0;
+						var type = path.match(/\.(\w+)$/)[1];
+						var size = file.size || 0;
 
 						if (info.enabled) {
 
@@ -408,6 +409,7 @@ function update(updatedCategory, updatedId){
 				if (themeInput) {
 					themeInput.checked = true;
 				}
+				// eslint-disable-next-line no-undef
 				setTheme(updatedId);
 			}
 		}
@@ -581,8 +583,8 @@ function buildCode(promises) {
 	promises = finalPromises;
 
 	// build
-	var i = 0,
-	    l = promises.length;
+	var i = 0;
+	var l = promises.length;
 	var code = {js: '', css: ''};
 	var errors = [];
 

components/prism-bsl.js

@@ -1,3 +1,5 @@
+/* eslint-disable no-misleading-character-class */
+
 // 1C:Enterprise
 // https://github.com/Diversus23/
 //

components/prism-coffeescript.js

@@ -1,11 +1,11 @@
 (function(Prism) {
 
 // Ignore comments starting with { to privilege string interpolation highlighting
-var comment = /#(?!\{).+/,
-    interpolation = {
-    	pattern: /#\{[^}]+\}/,
-    	alias: 'variable'
-    };
+var comment = /#(?!\{).+/;
+var interpolation = {
+	pattern: /#\{[^}]+\}/,
+	alias: 'variable'
+};
 
 Prism.languages.coffeescript = Prism.languages.extend('javascript', {
 	'comment': comment,

components/prism-core.js

@@ -426,8 +426,8 @@ var _ = {
 				if (o.hasOwnProperty(i)) {
 					callback.call(o, i, o[i], type || i);
 
-					var property = o[i],
-					    propertyType = _.util.type(property);
+					var property = o[i];
+					var propertyType = _.util.type(property);
 
 					if (propertyType === 'Object' && !visited[objId(property)]) {
 						visited[objId(property)] = true;
@@ -972,6 +972,7 @@ function matchGrammar(text, tokenList, grammar, startNode, startPos, rematch) {
 					}
 				}
 
+				// eslint-disable-next-line no-redeclare
 				var from = match.index,
 					matchStr = match[0],
 					before = str.slice(0, from),

components/prism-js-templates.js

@@ -170,7 +170,7 @@
 				var interpolationExpression = token.content;
 
 				var placeholder;
-				while (code.indexOf(placeholder = getPlaceholder(placeholderCounter++, language)) !== -1) { }
+				while (code.indexOf(placeholder = getPlaceholder(placeholderCounter++, language)) !== -1) { /* noop */ }
 				placeholderMap[placeholder] = interpolationExpression;
 				return placeholder;
 			}

components/prism-naniscript.js

@@ -151,7 +151,7 @@
 			}
 		}
 		return stack.length === 0;
-	};
+	}
 
 	/**
 	 * @param {string | Token | (string | Token)[]} token

components/prism-openqasm.js

@@ -11,7 +11,7 @@ Prism.languages.openqasm = {
 	'class-name': /\b(?:angle|bit|bool|creg|fixed|float|int|length|qreg|qubit|stretch|uint)\b/,
 	'function': /\b(?:sin|cos|tan|exp|ln|sqrt|rotl|rotr|popcount)\b(?=\s*\()/,
 
-	'constant': /\b(?:pi|tau|euler)\b|[π𝜏ℇ]/,
+	'constant': /\b(?:pi|tau|euler)\b|π|𝜏|ℇ/,
 	'number': {
 		pattern: /(^|[^.\w$])(?:\d+(?:\.\d*)?|\.\d+)(?:e[+-]?\d+)?(?:dt|ns|us|µs|ms|s)?/i,
 		lookbehind: true

components/prism-parser.js

@@ -58,7 +58,7 @@
 		}
 	});
 
-	parser = Prism.languages.insertBefore('inside', 'punctuation', {
+	Prism.languages.insertBefore('inside', 'punctuation', {
 		'expression': parser.expression,
 		'keyword': parser.keyword,
 		'variable': parser.variable,

components/prism-pure.js

@@ -44,6 +44,7 @@
 			alias: 'builtin'
 		},
 		// Any combination of operator chars can be an operator
+		// eslint-disable-next-line no-misleading-character-class
 		'operator': /(?:[!"#$%&'*+,\-.\/:<=>?@\\^`|~\u00a1-\u00bf\u00d7-\u00f7\u20d0-\u2bff]|\b_+\b)+|\b(?:and|div|mod|not|or)\b/,
 		// FIXME: How can we prevent | and , to be highlighted as operator when they are used alone?
 		'punctuation': /[(){}\[\];,|]/