feat!: add support for eslint v9, drop support for eslint v8 & v7 @W-18423706 (#44)

* feat!: add support for eslint v9, drop support for eslint v8 & v7 @W-18423706

BREAKING CHANGE: dropping support for ESLint v7 and v8. The only supported option is ESLint v9

* feat: make config flat

* fix: update rules to new context apis

* fix: fix rule tester script to use right module type

* docs: update readme

* fix: update lock file

* fix: update image used for ci

* fix: address PR comments

* fix: address PR comments to renable all recommended rules from base config

* fix: formatting to add trailing commas

Author: ravijayaramappa

.circleci/config.yml

@@ -1,6 +1,6 @@
 version: 2.1
 
-supported-eslint-versions: &supported-eslint-versions ["local", "7"]
+supported-eslint-versions: &supported-eslint-versions ["local"]
 
 jobs:
   build:
@@ -12,7 +12,7 @@ jobs:
           frozen in the package-lock.json is used.
         default: "local"
     docker:
-      - image: circleci/node
+      - image: cimg/node:18.18.0
     steps:
       - checkout
 
@@ -47,4 +47,4 @@ workflows:
       - build:
           matrix:
             parameters:
-              eslint-version: *supported-eslint-versions
+              eslint-version: *supported-eslint-versions

.eslintrc.js

@@ -13,19 +13,20 @@ npm install --save-dev @salesforce/eslint-plugin-aura
 
 ## Usage
 
+> [!IMPORTANT]
+> Starting with v3.0.0, `@salesforce/eslint-plugin-aura` only supports `eslint@v9`. Use `@salesforce/eslint-plugin-aura@v2.x` for older versions of ESLint.
+
 Add this plugin to your ESLint configuration and extend your desired configuration. See
-[ESLint documentation](http://eslint.org/docs/user-guide/configuring#configuring-plugins) for details.
-
-Example:
-
-```json
-{
-  "plugins": ["@salesforce/eslint-plugin-aura"],
-  "extends": [
-    "plugin:@salesforce/eslint-plugin-aura/recommended",
-    "plugin:@salesforce/eslint-plugin-aura/locker"
-  ]
-}
+[ESLint documentation](https://eslint.org/docs/latest/use/configure/plugins) for details.
+
+Example `eslint.config.js`:
+
+```js
+const eslintAura = require('@salesforce/eslint-plugin-aura');
+module.exports = [
+  ...eslintAura.configs.recommended,
+  ...eslintAura.configs.locker,
+];
 ```
 
 ## Rules
@@ -52,7 +53,7 @@ Example:
 
 This package exposes 2 configurations for your usage.
 
-### `@salesforce/eslint-plugin-aura/recommended` configuration
+### Recommended configuration
 
 **Goal:**
 Prevent common pitfalls with Lightning component development, and enforce other Salesforce platform restrictions.
@@ -63,7 +64,36 @@ Prevent common pitfalls with Lightning component development, and enforce other
 - Proper usage of the `$A` global, via the [`aura-api`](https://github.com/forcedotcom/eslint-plugin-aura/blob/master/docs/rules/aura-api.md) rule.
 - Browser compatibility rules for [Salesforce supported browsers](https://help.salesforce.com/articleView?id=sf.getstart_browsers_sfx.htm&type=5).
 
-### `@salesforce/eslint-plugin-aura/locker` configuration
+**Usage**
+
+```js
+// eslint.config.js
+const eslintPluginAura = require('@salesforce/eslint-plugin-aura');
+
+module.exports = [...eslintPluginAura.configs.recommended];
+```
+
+#### Migration to ESLint v9
+
+The recommended configurations extend ESLint's `js/recommended` [predefined configuration](https://eslint.org/docs/latest/use/configure/configuration-files#using-predefined-configurations) (previously known as `eslint:recommended`). ESLint v9 has added 4 new rules to the recommended config, you can read about that [here](https://eslint.org/docs/latest/use/migrate-to-9.0.0#eslint-recommended). You can opt to turn these off for backwards compatibility.
+
+```js
+// eslint.config.js
+const eslintAura = require('@salesforce/eslint-plugin-aura');
+module.exports = [
+  ...eslintAura.configs.recommended,
+  {
+    rules: {
+      'no-empty-static-block': 'off',
+      'no-constant-binary-expression': 'off',
+      'no-new-native-non-constructor': 'off',
+      'no-unused-private-class-members': 'off',
+    },
+  },
+];
+```
+
+### Lightning Locker configuration
 
 **Goal:**
 Prevent [Lightning Locker](https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/security_code.htm) violations.
@@ -73,3 +103,12 @@ Prevent [Lightning Locker](https://developer.salesforce.com/docs/atlas.en-us.lig
 - `@salesforce/eslint-plugin-aura/recommended` rules.
 - Proper usage of `document` and `window` via the [`secure-document`](https://github.com/forcedotcom/eslint-plugin-aura/blob/master/docs/rules/secure-document.md) and [`secure-window`](https://github.com/forcedotcom/eslint-plugin-aura/blob/master/docs/rules/secure-window.md) rules, respectively.
 - Proper usage of Javascript intrinsic APIs via the [`ecma-intrinsics`](https://github.com/forcedotcom/eslint-plugin-aura/blob/master/docs/rules/ecma-intrinsics.md) rule.
+
+**Usage**
+
+```js
+// eslint.config.js
+const eslintPluginAura = require('@salesforce/eslint-plugin-aura');
+
+module.exports = [...eslintPluginAura.configs.locker];
+```

README.md

@@ -0,0 +1,22 @@
+'use strict';
+
+const globals = require('globals');
+const js = require('@eslint/js');
+
+module.exports = [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      ecmaVersion: 2018,
+      globals: {
+        ...globals.mocha,
+        ...globals.node,
+      },
+      sourceType: 'commonjs',
+    },
+
+    rules: {
+      strict: ['error'],
+    },
+  },
+];

eslint.config.js

@@ -1,14 +1,16 @@
 'use strict';
+const recommended = require('./recommended');
 
-module.exports = {
-  extends: [require.resolve('./recommended')],
+module.exports = [
+  ...recommended,
+  {
+    rules: {
+      'no-array-constructor': 'error', // help with instanceof
 
-  rules: {
-    'no-array-constructor': 'error', // help with instanceof
-
-    // Locker specific rules
-    '@salesforce/aura/ecma-intrinsics': 'error',
-    '@salesforce/aura/secure-document': 'error',
-    '@salesforce/aura/secure-window': 'error',
+      // Locker specific rules
+      '@salesforce/aura/ecma-intrinsics': 'error',
+      '@salesforce/aura/secure-document': 'error',
+      '@salesforce/aura/secure-window': 'error',
+    },
   },
-};
+];

lib/configs/locker.js

@@ -1,113 +1,107 @@
 'use strict';
+const eslintJs = require('@eslint/js');
+const globals = require('globals');
 
-module.exports = {
-  extends: ['eslint:recommended', 'plugin:compat/recommended'],
-
-  plugins: ['compat', '@salesforce/eslint-plugin-aura'],
-
-  env: {
-    browser: true,
-  },
-
-  parserOptions: {
-    ecmaVersion: 5,
-  },
-
-  globals: {
-    $A: true,
-    AuraContext: true,
-    AuraSerializationService: true,
-    AuraExpressionService: true,
-    AuraEventService: true,
-    AuraLocalizationService: true,
-    AuraStorageService: true,
-    AuraStyleService: true,
-    MetricsService: true,
-    AuraDevToolService: true,
-    Component: true,
-    CKEDITOR: true,
-    FORCE: true,
-    moment: true,
-    exports: true,
-    iScroll: true,
-    Promise: true,
-  },
-
-  rules: {
-    // Possible errors
-    // https://eslint.org/docs/rules/#possible-errors
-    'no-console': 'error',
+const auraGlobals = {
+  $A: true,
+  AuraContext: true,
+  AuraSerializationService: true,
+  AuraExpressionService: true,
+  AuraEventService: true,
+  AuraLocalizationService: true,
+  AuraStorageService: true,
+  AuraStyleService: true,
+  MetricsService: true,
+  AuraDevToolService: true,
+  Component: true,
+  CKEDITOR: true,
+  FORCE: true,
+  moment: true,
+  exports: true,
+  iScroll: true,
+  Promise: true,
+};
 
-    // Best practices
-    // https://eslint.org/docs/rules/#best-practices
-    'array-callback-return': 'error',
-    'consistent-return': 'error',
-    'default-case': 'error',
-    'dot-notation': ['error', { allowKeywords: true }],
-    eqeqeq: ['error', 'smart'],
-    'guard-for-in': 'error',
-    'no-alert': 'error',
-    'no-caller': 'error',
-    'no-else-return': 'error',
-    'no-empty-function': [
-      'error',
-      {
-        allow: ['arrowFunctions', 'functions', 'methods'],
+module.exports = [
+  eslintJs.configs.recommended,
+  {
+    languageOptions: {
+      ecmaVersion: 5,
+      // https://eslint.org/docs/latest/use/migrate-to-9.0.0#-flatruletester-is-now-ruletester
+      // New default sourceType is 'module', override to 'script' for backward compatibility
+      sourceType: 'script',
+      globals: {
+        ...globals.browser,
+        ...auraGlobals,
       },
-    ],
-    'no-eval': 'error',
-    'no-extend-native': 'error',
-    'no-extra-bind': 'error',
-    'no-floating-decimal': 'error',
-    'no-implied-eval': 'error',
-    'no-iterator': 'error',
-    'no-labels': 'error',
-    'no-loop-func': 'error',
-    'no-multi-str': 'error',
-    'no-new': 'error',
-    'no-new-func': 'error',
-    'no-new-object': 'error',
-    'no-new-wrappers': 'error',
-    'no-octal-escape': 'error',
-    'no-proto': 'error',
-    'no-return-assign': 'error',
-    'no-return-await': 'error',
-    'no-script-url': 'error',
-    'no-self-compare': 'error',
-    'no-sequences': 'error',
-    'no-throw-literal': 'error',
-    'no-useless-concat': 'error',
-    'no-useless-escape': 'error',
-    'no-useless-return': 'error',
-    'no-unused-expressions': 'error',
-    'no-void': 'error',
-    'no-with': 'error',
-    radix: 'error',
-    'vars-on-top': 'error',
-    'wrap-iife': ['error', 'any'],
+    },
+    rules: {
+      // Possible errors
+      // https://eslint.org/docs/rules/#possible-errors
+      'no-console': 'error',
 
-    // Variables
-    // https://eslint.org/docs/rules/#variables
-    'no-label-var': 'error',
-    'no-shadow': 'error',
-    'no-shadow-restricted-names': 'error',
-    'no-undef-init': 'error',
-    'no-unused-vars': ['error', { vars: 'all', args: 'after-used' }],
-    'no-use-before-define': ['error', { functions: false }],
+      // Best practices
+      // https://eslint.org/docs/rules/#best-practices
+      'array-callback-return': 'error',
+      'consistent-return': 'error',
+      'default-case': 'error',
+      'dot-notation': ['error', { allowKeywords: true }],
+      eqeqeq: ['error', 'smart'],
+      'guard-for-in': 'error',
+      'no-alert': 'error',
+      'no-caller': 'error',
+      'no-else-return': 'error',
+      'no-empty-function': [
+        'error',
+        {
+          allow: ['arrowFunctions', 'functions', 'methods'],
+        },
+      ],
+      'no-eval': 'error',
+      'no-extend-native': 'error',
+      'no-extra-bind': 'error',
+      'no-floating-decimal': 'error',
+      'no-implied-eval': 'error',
+      'no-iterator': 'error',
+      'no-labels': 'error',
+      'no-loop-func': 'error',
+      'no-multi-str': 'error',
+      'no-new': 'error',
+      'no-new-func': 'error',
+      'no-new-object': 'error',
+      'no-new-wrappers': 'error',
+      'no-octal-escape': 'error',
+      'no-proto': 'error',
+      'no-return-assign': 'error',
+      'no-return-await': 'error',
+      'no-script-url': 'error',
+      'no-self-compare': 'error',
+      'no-sequences': 'error',
+      'no-throw-literal': 'error',
+      'no-useless-concat': 'error',
+      'no-useless-escape': 'error',
+      'no-useless-return': 'error',
+      'no-unused-expressions': 'error',
+      'no-void': 'error',
+      'no-with': 'error',
+      radix: 'error',
+      'vars-on-top': 'error',
+      'wrap-iife': ['error', 'any'],
 
-    // Aura specific rules
-    '@salesforce/aura/aura-api': 'error',
-    '@salesforce/aura/getevt-markup-prefix': 'error',
-    '@salesforce/aura/no-deprecated-aura-error': 'error',
-    '@salesforce/aura/no-deprecated-component-creation': 'error',
-  },
+      // Variables
+      // https://eslint.org/docs/rules/#variables
+      'no-label-var': 'error',
+      'no-shadow': 'error',
+      'no-shadow-restricted-names': 'error',
+      'no-undef-init': 'error',
+      'no-unused-vars': ['error', { vars: 'all', args: 'after-used' }],
+      'no-use-before-define': ['error', { functions: false }],
 
-  // Configuration for compat eslint plugin:
-  // https://github.com/amilajack/eslint-plugin-compat#adding-polyfills
-  settings: {
-    // https://help.salesforce.com/articleView?id=getstart_browsers_sfx.htm&type=5
-    targets:
-      'last 1 version, last 1 firefox version, last 1 edge version, ie 11, not safari < 12',
-    polyfills: ['Promise'],
+      // Aura specific rules
+      '@salesforce/aura/aura-api': 'error',
+      '@salesforce/aura/getevt-markup-prefix': 'error',
+      '@salesforce/aura/no-deprecated-aura-error': 'error',
+      '@salesforce/aura/no-deprecated-component-creation': 'error',
+    },
   },
-};
+];