Update ESLint rules and pass all of them

This is done via a new script, npm run lint-is-complete, which finds any unset rules.

The majority of changes are driven by preferring destructuring and spacing changes.

Author: domenic

.eslintignore

@@ -4,7 +4,6 @@ benchmark/browser-bundle.js
 test/worker-bundle.js
 
 lib/jsdom/browser/default-stylesheet.js
-lib/jsdom/level2/style.js
 lib/jsdom/level3/xpath.js
 
 lib/jsdom/living/generated/**
@@ -29,3 +28,4 @@ test/to-port-to-wpts/script.js
 test/web-platform-tests/tests
 test/web-platform-tests/to-upstream/dom/nodes/Document-createComment-createTextNode.js
 test/web-platform-tests/to-upstream/domparsing/DOMParser-dont-upstream.html
+test/web-platform-tests/to-upstream/html/semantics/scripting-1/the-script-element/script-languages-dont-upstream.html

.eslintrc.json

@@ -9,7 +9,10 @@
   },
   "rules": {
     // Possible errors
-    "comma-dangle": ["error", "never"],
+    "for-direction": "error",
+    "getter-return": "error",
+    "no-await-in-loop": "error",
+    "no-compare-neg-zero": "error",
     "no-cond-assign": ["error", "except-parens"],
     "no-console": "error",
     "no-constant-condition": ["error", { "checkLoops": false }],
@@ -28,13 +31,15 @@
     "no-inner-declarations": "off",
     "no-invalid-regexp": "error",
     "no-irregular-whitespace": "error",
-    "no-negated-in-lhs": "error",
     "no-obj-calls": "error",
+    "no-prototype-builtins": "error",
     "no-regex-spaces": "error",
     "no-sparse-arrays": "error",
+    "no-template-curly-in-string": "error",
     "no-unexpected-multiline": "error",
     "no-unreachable": "error",
     "no-unsafe-finally": "off",
+    "no-unsafe-negation": "error",
     "use-isnan": "error",
     "valid-jsdoc": "off",
     "valid-typeof": "error",
@@ -43,6 +48,7 @@
     "accessor-pairs": "error",
     "array-callback-return": "error",
     "block-scoped-var": "off",
+    "class-methods-use-this": "off",
     "complexity": "off",
     "consistent-return": "error",
     "curly": ["error", "all"],
@@ -65,6 +71,7 @@
     "no-extra-label": "error",
     "no-fallthrough": "error",
     "no-floating-decimal": "error",
+    "no-global-assign": "error",
     "no-implicit-coercion": "error",
     "no-implicit-globals": "error",
     "no-implied-eval": "off",
@@ -76,7 +83,6 @@
     "no-magic-numbers": "off",
     "no-multi-spaces": "error",
     "no-multi-str": "error",
-    "no-native-reassign": "error",
     "no-new": "error",
     "no-new-func": "error",
     "no-new-wrappers": "error",
@@ -86,7 +92,9 @@
     "no-process-env": "error",
     "no-proto": "error",
     "no-redeclare": "error",
+    "no-restricted-properties": "off",
     "no-return-assign": ["error", "except-parens"],
+    "no-return-await": "error",
     "no-script-url": "off",
     "no-self-assign": "error",
     "no-self-compare": "error",
@@ -98,10 +106,13 @@
     "no-useless-call": "error",
     "no-useless-concat": "error",
     "no-useless-escape": "error",
+    "no-useless-return": "error",
     "no-void": "error",
     "no-warning-comments": "off",
     "no-with": "error",
+    "prefer-promise-reject-errors": "error",
     "radix": ["error", "as-needed"],
+    "require-await": "error",
     "vars-on-top": "off",
     "wrap-iife": ["error", "outside"],
     "yoda": ["error", "never"],
@@ -127,84 +138,111 @@
     "callback-return": "off",
     "global-require": "error",
     "handle-callback-err": "error",
+    "no-buffer-constructor": "error",
     "no-mixed-requires": ["error", true],
     "no-new-require": "error",
     "no-path-concat": "error",
     "no-process-exit": "error",
-    "no-restricted-imports": "off",
     "no-restricted-modules": "off",
     "no-sync": "off",
 
     // Stylistic Issues
+    "array-bracket-newline": ["error", { "multiline": true }],
     "array-bracket-spacing": ["error", "never"],
+    "array-element-newline": ["off"],
     "block-spacing": ["error", "always"],
     "brace-style": ["error", "1tbs", { "allowSingleLine": false }],
     "camelcase": ["error", { "properties": "always" }],
+    "capitalized-comments": "off",
+    "comma-dangle": ["error", "never"],
     "comma-spacing": ["error", { "before": false, "after": true }],
     "comma-style": ["error", "last"],
     "computed-property-spacing": ["error", "never"],
     "consistent-this": "off",
     "eol-last": "error",
+    "func-call-spacing": ["error", "never"],
+    "func-name-matching": ["error"],
     "func-names": "off",
     "func-style": ["error", "declaration"],
+    "function-paren-newline": ["error", "multiline"],
     "id-blacklist": "off",
     "id-length": "off",
     "id-match": "off",
-    "indent": ["error", 2, { "SwitchCase": 1 }],
+    "indent": ["error", 2, { "SwitchCase": 1, "CallExpression": {"arguments": "first"}, "FunctionExpression": {"parameters": "first"}, "ignoredNodes": ["ConditionalExpression"] }],
     "jsx-quotes": "off",
     "key-spacing": ["error", { "beforeColon": false, "afterColon": true, "mode": "strict" }],
     "keyword-spacing": ["error", { "before": true, "after": true }],
+    "line-comment-position": "off",
     "linebreak-style": ["error", "unix"],
     "lines-around-comment": "off",
     "max-depth": "off",
     "max-len": ["error", 120, { "ignoreUrls": true }],
+    "max-lines": "off",
     "max-nested-callbacks": "off",
     "max-params": "off",
     "max-statements": "off",
     "max-statements-per-line": ["error", { "max": 1 }],
+    "multiline-ternary": ["error", "always-multiline"],
     "new-cap": ["error", { "capIsNewExceptions": ["USVString", "DOMString"] }],
     "new-parens": "error",
-    "newline-after-var": "off",
-    "newline-before-return": "off",
     "newline-per-chained-call": "off",
     "no-array-constructor": "error",
     "no-bitwise": "off",
     "no-continue": "off",
     "no-inline-comments": "off",
     "no-lonely-if": "error",
+    "no-mixed-operators": [
+      "error",
+      {
+        "groups": [
+          ["&", "|", "^", "~", "<<", ">>", ">>>"],
+          ["==", "!=", "===", "!==", ">", ">=", "<", "<="],
+          ["&&", "||"],
+          ["in", "instanceof"]
+        ]
+      }
+    ],
     "no-mixed-spaces-and-tabs": "error",
+    "no-multi-assign": "off",
     "no-multiple-empty-lines": "error",
     "no-negated-condition": "off",
     "no-nested-ternary": "error",
     "no-new-object": "error",
     "no-plusplus": "off",
     "no-restricted-syntax": "off",
-    "no-spaced-func": "error",
+    "no-tabs": "error",
     "no-ternary": "off",
     "no-trailing-spaces": "error",
     "no-underscore-dangle": "off",
     "no-unneeded-ternary": "error",
     "no-whitespace-before-property": "error",
+    "nonblock-statement-body-position": "error",
+    "object-curly-newline": ["error", { "consistent": true }],
     "object-curly-spacing": ["error", "always"],
     "object-property-newline": "off",
     "one-var": ["error", "never"],
     "one-var-declaration-per-line": ["error", "initializations"],
     "operator-assignment": ["error", "always"],
     "operator-linebreak": ["error", "after"],
     "padded-blocks": ["error", "never"],
+    "padding-line-between-statements": "off",
     "quote-props": ["error", "as-needed"],
     "quotes": ["error", "double", { "avoidEscape": true, "allowTemplateLiterals": true }],
     "require-jsdoc": "off",
     "semi": ["error", "always"],
     "semi-spacing": "error",
-    "sort-imports": "off",
+    "semi-style": "error",
+    "sort-keys": "off",
     "sort-vars": "off",
     "space-before-blocks": ["error", "always"],
     "space-before-function-paren": ["error", { "anonymous": "always", "named": "never" }],
     "space-in-parens": ["error", "never"],
     "space-infix-ops": "error",
     "space-unary-ops": ["error", { "words": true, "nonwords": false }],
     "spaced-comment": ["error", "always", { "markers": ["///"] }],
+    "switch-colon-spacing": "error",
+    "template-tag-spacing": "error",
+    "unicode-bom": "error",
     "wrap-regex": "off",
 
     // ECMAScript 6
@@ -219,18 +257,24 @@
     "no-dupe-class-members": "error",
     "no-duplicate-imports": "error",
     "no-new-symbol": "error",
+    "no-restricted-imports": "off",
     "no-this-before-super": "error",
     "no-useless-computed-key": "error",
     "no-useless-constructor": "error",
+    "no-useless-rename": "error",
     "no-var": "error",
     "object-shorthand": "error",
     "prefer-arrow-callback": "error",
     "prefer-const": ["error", { "ignoreReadBeforeAssign": true }],
-    "prefer-reflect": "off",
+    "prefer-destructuring": ["error", { "VariableDeclarator": { "array": false, "object": true }, "AssignmentExpression": { "array": false, "object": false } }, { "enforceForRenamedProperties": false }],
+    "prefer-numeric-literals": "error",
     "prefer-rest-params": "off",
     "prefer-spread": "error",
     "prefer-template": "off",
     "require-yield": "error",
+    "rest-spread-spacing": "error",
+    "sort-imports": "off",
+    "symbol-description": "error",
     "template-curly-spacing": ["error", "never"],
     "yield-star-spacing": ["error", "after"]
   }

benchmark/document-suite.js

@@ -20,16 +20,12 @@ function addBenchmark(suite, benchmark) {
   }
 }
 
-function benchmarkFunctions(document, options) {
-  const setup = options.setup || noop;
-  const fn = options.fn;
-  const teardown = options.teardown || noop;
-
+function benchmarkFunctions(document, { setup = noop, fn, teardown = noop, defer }) {
   return {
     setup() {
       setup.call(this, document);
     },
-    fn: options.defer ?
+    fn: defer ?
         function (deferred) {
           fn.call(this, deferred, document);
         } :

benchmark/path-to-suites.js

@@ -11,7 +11,7 @@ module.exports = function pathToSuites(benchmarks, paths) {
       let suites = benchmarks;
 
       for (const part of parts) {
-        suites = suites.hasOwnProperty(part) && suites[part];
+        suites = Object.prototype.hasOwnProperty.call(suites, part) && suites[part];
         if (!suites) {
           throw Error("Invalid suite: '" + path + "'");
         }

benchmark/runner.js

@@ -7,7 +7,7 @@ const pathToSuites = require("./path-to-suites");
 const benchmarks = require(".");
 const fs = require("fs");
 const path = require("path");
-const toFileUrl = require("../lib/jsdom/utils").toFileUrl;
+const { toFileUrl } = require("../lib/jsdom/utils");
 
 const optimist = require("optimist")
   .usage("Run the jsdom benchmark suite")
@@ -31,8 +31,10 @@ if (optimist.argv.bundle) {
   bundle.bundle()
     .pipe(fs.createWriteStream(path.resolve(__dirname, "browser-bundle.js")))
     .on("finish", () => {
-      console.info("Open the following page in Chrome to begin benchmarking:",
-                   toFileUrl(path.resolve(__dirname, "browser-runner.html")));
+      console.info(
+        "Open the following page in Chrome to begin benchmarking:",
+        toFileUrl(path.resolve(__dirname, "browser-runner.html"))
+      );
     });
   return;
 }

lib/jsdom/browser/Window.js

@@ -10,8 +10,7 @@ const namedPropertiesWindow = require("../living/named-properties-window");
 const cssom = require("cssom");
 const postMessage = require("../living/post-message");
 const DOMException = require("domexception");
-const btoa = require("abab").btoa;
-const atob = require("abab").atob;
+const { btoa, atob } = require("abab");
 const idlUtils = require("../living/generated/utils");
 const createXMLHttpRequest = require("../living/xmlhttprequest");
 const createFileReader = require("../living/generated/FileReader").createInterface;
@@ -107,8 +106,7 @@ function Window(options) {
     if (options.virtualConsole instanceof VirtualConsole) {
       this._virtualConsole = options.virtualConsole;
     } else {
-      throw new TypeError(
-        "options.virtualConsole must be a VirtualConsole (from createVirtualConsole)");
+      throw new TypeError("options.virtualConsole must be a VirtualConsole (from createVirtualConsole)");
     }
   } else {
     this._virtualConsole = new VirtualConsole();
@@ -386,7 +384,7 @@ function Window(options) {
     const nodeImpl = idlUtils.implForWrapper(node);
     const s = node.style;
     const cs = new CSSStyleDeclaration();
-    const forEach = Array.prototype.forEach;
+    const { forEach } = Array.prototype;
 
     function setPropertiesFromRule(rule) {
       if (!rule.selectorText) {

lib/jsdom/browser/htmltodom.js

@@ -33,9 +33,7 @@ module.exports = class HTMLToDOM {
 
     let dom;
     if (fragment) {
-      const parentElement = htmlparser2Adapter.createElement(
-        element.tagName.toLowerCase(), element.namespaceURI, []
-      );
+      const parentElement = htmlparser2Adapter.createElement(element.tagName.toLowerCase(), element.namespaceURI, []);
 
       options.treeAdapter = htmlparser2Adapter;
       dom = this.parser.parseFragment(parentElement, html, options);
@@ -148,7 +146,7 @@ module.exports = class HTMLToDOM {
 };
 
 function setChild(core, parentImpl, node) {
-  const currentDocument = parentImpl && parentImpl._ownerDocument || parentImpl;
+  const currentDocument = (parentImpl && parentImpl._ownerDocument) || parentImpl;
 
   let newNode;
   let isTemplateContents = false;
@@ -184,10 +182,13 @@ function setChild(core, parentImpl, node) {
         newNode = currentDocument.createProcessingInstruction(node.name.substring(1), data);
       } else if (node.name.toLowerCase() === "!doctype") {
         if (node["x-name"] !== undefined) { // parse5 supports doctypes directly
-          newNode = createDocumentTypeInternal(core, currentDocument,
+          newNode = createDocumentTypeInternal(
+            core,
+            currentDocument,
             node["x-name"] || "",
             node["x-publicId"] || "",
-            node["x-systemId"] || "");
+            node["x-systemId"] || ""
+          );
         } else {
           newNode = parseDocType(core, currentDocument, "<" + node.data + ">");
         }
@@ -204,16 +205,10 @@ function setChild(core, parentImpl, node) {
   if (node.attribs) {
     Object.keys(node.attribs).forEach(localName => {
       const value = node.attribs[localName];
-      let prefix =
-        node["x-attribsPrefix"] &&
-        Object.prototype.hasOwnProperty.call(node["x-attribsPrefix"], localName) &&
-        node["x-attribsPrefix"][localName] || null;
-      const namespace =
-        node["x-attribsNamespace"] &&
-        Object.prototype.hasOwnProperty.call(node["x-attribsNamespace"], localName) &&
-        node["x-attribsNamespace"][localName] || null;
+      let prefix = getXPropForLocalName(node, "x-attribsPrefix", localName);
+      const namespace = getXPropForLocalName(node, "x-attribsNamespace", localName);
       if (prefix === "xmlns" && localName === "") {
-         // intended weirdness in node-sax, see https://github.com/isaacs/sax-js/issues/165
+        // intended weirdness in node-sax, see https://github.com/isaacs/sax-js/issues/165
         localName = prefix;
         prefix = null;
       }
@@ -239,6 +234,15 @@ function setChild(core, parentImpl, node) {
   return newNode;
 }
 
+function getXPropForLocalName(node, xprop, localName) {
+  const xpropValue = node[xprop];
+  if (xpropValue && Object.prototype.hasOwnProperty.call(xpropValue, localName)) {
+    return xpropValue[localName] || null;
+  }
+
+  return null;
+}
+
 const HTML5_DOCTYPE = /<!doctype html>/i;
 const PUBLIC_DOCTYPE = /<!doctype\s+([^\s]+)\s+public\s+"([^"]+)"\s+"([^"]+)"/i;
 const SYSTEM_DOCTYPE = /<!doctype\s+([^\s]+)\s+system\s+"([^"]+)"/i;