Create shareable ESLint config

.gitignore

@@ -1 +1,4 @@
+.DS_Store
+.idea
+.vscode
 node_modules

README.md

@@ -1,20 +1,8 @@
-Forum One JavaScript Coding Style
+Forum One JavaScript Tools
 ================================
-
-Our coding conventions are minor modifications of [Airbnb's legacy ES5 configuration](https://github.com/airbnb/javascript/tree/es5-deprecated/es5), with customizations for specific environments.
-
-Usage
------
-
-1. First, you'll need ESLint. Here's a [quick start guide](http://eslint.org/docs/user-guide/getting-started).
-2. For bonus points, get your [editor integrated](http://eslint.org/docs/user-guide/integrations).
-3. Since we're extending another config, you'll need to read the installation instructions for [`airbnb-base/legacy`](https://www.npmjs.com/package/eslint-config-airbnb-base#eslint-config-airbnb-baselegacy).
-4. Run `npm install eslint-config-forumone-es5`.
-5. Add `extends: 'forumone-es5'` to your ESLint configuration file.
-
 Modules
 -------
 
 ### eslint-config-forumone-es5
 
-Forum One's base ES5 ESLint configuration.
+Forum One's base JavaScript ESLint configuration.

packages/eslint-config-forumone-es5/CHANGELOG.md

@@ -0,0 +1,6 @@
+# Changelog
+
+## 3.0.0
+**Breaking Changes**: Basically everything. Requires ESLint 9 and switches to
+eslint:recommended as the base config. You probably aren't using version 2, but
+if you are, this amounts to a new start.

packages/eslint-config-forumone-es5/README.md

@@ -1,4 +1,14 @@
-Forum One JavaScript Coding Style (ES5 Edition)
-----------------------------------------------
+Forum One JavaScript Coding Style
+================================
 
-See [forumone/javascript](https://github.com/forumone/javascript) on GitHub for a longer intro.
+Our JavaScript code style conventions are based on:
+- [ESLint's Recommended Config](https://eslint.org/docs/latest/rules/)
+- [TypeScript ESLint](https://typescript-eslint.io/)
+- [Prettier](https://prettier.io/docs/related-projects#eslint-integrations)
+- [Prettier Plugin: Organize Imports](https://github.com/simonhaenisch/prettier-plugin-organize-imports)
+with customizations for specific environments and team practices.
+
+Usage
+-----
+1. Run `npm install eslint-config-forumone-es5`.
+2. Add `extends: 'forumone-es5'` to your ESLint configuration file.

packages/eslint-config-forumone-es5/index.js

@@ -1,65 +1,94 @@
-/* eslint-env node, commonjs */
-
-exports.ecmaFeatures = {
-  impliedStrict: true,
-};
-
-// Our ES5 projects are exclusively browser-focused
-exports.env = {
-  browser: true,
-  node: false,
-  commonjs: false,
-};
-
-exports.extends = 'airbnb-base/legacy';
-
-exports.rules = {
-  // Overrides of airbnb-base/legacy
-
-  // IE8 is dead, we can require trailing commas safely
-  'comma-dangle': ['error', 'always-multiline'],
-
-  // block-scoped-var and no-use-before-define cover the use cases here
-  // no need to manually hoist as well
-  'vars-on-top': ['off'],
-
-  // Style guidance left to the programmer
-  'no-else-return': ['off'],
-  'func-names': ['off'],
-
-  // Function hoisting is always safe
-  'no-use-before-define': ['error', {
-    functions: false,
-  }],
-
-  // Allow conditionals in loops (but only if you promise that you know what you're doing)
-  'no-cond-assign': ['error', 'except-parens'],
-
-  // Unconditionally require curly braces
-  curly: ['error', 'all'],
-
-  // Additional rules
-
-  // Don't leak globals
-  'no-implicit-globals': 'error',
-
-  // Disallow superfluous parentheses, unless you need to disambiguate precedence
-  'no-extra-parens': ['error', 'all', {
-    conditionalAssign: false,
-    nestedBinaryExpressions: false,
-  }],
-
-  // Eventually, this will be an error (and also require parameter descriptions)
-  'valid-jsdoc': ['warn', {
-    requireReturn: false,
-    requireParamDescription: false,
-    requireReturnDescription: false,
-
-    prefer: {
-      arg: 'param',
-      argument: 'param',
-
-      returns: 'return',
+// @ts-check
+
+import eslint from "@eslint/js";
+import tseslint from "typescript-eslint";
+import prettier from "eslint-config-prettier";
+import prettierPlugin from "eslint-plugin-prettier";
+import globals from "globals";
+
+/**
+ * @type {import('@typescript-eslint/utils').TSESLint.FlatConfig.ConfigFile}
+ */
+const config = tseslint.config(
+  eslint.configs.recommended,
+  tseslint.configs.recommended,
+  prettier,
+  {
+    languageOptions: {
+      ecmaVersion: "latest",
+      globals: {
+        ...globals.node,
+        ...globals.browser,
+      },
+      sourceType: "module",
+    },
+    plugins: {
+      "@typescript-eslint": tseslint.plugin,
+      prettier: prettierPlugin,
+    },
+    rules: {
+      "@typescript-eslint/explicit-module-boundary-types": "off",
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        {
+          ignoreRestSiblings: true,
+          varsIgnorePattern: "^_",
+          argsIgnorePattern: "^_",
+          caughtErrorsIgnorePattern: "^_",
+        },
+      ],
+      "@typescript-eslint/no-explicit-any": "error",
+      "@typescript-eslint/no-empty-interface": [
+        "error",
+        {
+          allowSingleExtends: true,
+        },
+      ],
+      "@typescript-eslint/no-use-before-define": "error",
+      eqeqeq: "error",
+      "no-console": [
+        "error",
+        {
+          allow: ["warn", "error"],
+        },
+      ],
+      "no-duplicate-imports": "error",
+      "no-lonely-if": "error",
+      "no-param-reassign": [
+        // Allow modifying props, esp. for DOM Nodes
+        "error",
+        {
+          props: false,
+        },
+      ],
+      "no-shadow": "error",
+      "no-useless-assignment": "error",
+      "no-var": "error",
+      "object-shorthand": ["error", "always"],
+      "prefer-const": "error",
+      "prefer-destructuring": [
+        "error",
+        {
+          array: false,
+          object: true,
+        },
+      ],
+      "prefer-spread": "error",
+      "prettier/prettier": "error",
+    },
+  },
+  // TypeScript-specific additions
+  {
+    files: ["*.ts", "*.tsx"],
+    extends: [tseslint.configs.recommendedTypeChecked],
+    languageOptions: {
+      parserOptions: {
+        projectService: true,
+      },
+    },
+    rules: {
+      "@typescript-eslint/explicit-module-boundary-types": ["error"],
     },
-  }],
-};
+  },
+);
+export default config;