INCOMPLETE: waiting on:

1. eslint-plugin-import
2. ideally, eslint-plugin-escompat when eslint 9 version ready
3. ideally, eslint-plugin-unsanitized (waiting on typescript-eslint))
4. ideally, @fintechstudios/eslint-plugin-chai-as-promised
5. ideally, eslint-plugin-mocha-cleanup

feat: switch to flat config

BREAKING CHANGE:

Requires Node 18.20.3+

Also:
- chore: update globals, semver
- chore: some TS work
- feat: detects sourceType automatically for .js files too, based on `package.json`
- fix: drop no-unpublished-import checks from rc configs
- fix: add eslint.config.js to ESM configs

+babel.js

@@ -1,26 +1,33 @@
-'use strict';
-
-// Move to own repo so can have `@babel/eslint-parser` and `@babel/eslint-plugin` as deps.
+// Move to own repo so can have `@babel/eslint-parser` and
+//   `@babel/eslint-plugin` as deps.
+/* eslint-disable jsdoc/imports-as-dependencies -- Bug? */
 
 // Adapted from MIT-licensed: https://github.com/futagoza/eslint-config-futagozaryuu/blob/master/packages/%40futagoza/eslint-config-core/stylistic-issues.js
 
+// Types: https://github.com/babel/babel/issues/16221
+
+import babelParser from '@babel/eslint-parser';
+import babelEslintPlugin from '@babel/eslint-plugin';
+
 /**
  * Allows passing in a whole config to wrap.
- * @param {ESLintConfig} config
- * @returns {ESLintConfig}
+ * @param {import('eslint').Linter.FlatConfig} config
+ * @returns {import('eslint').Linter.FlatConfig}
  */
-module.exports = function (config) {
+export default function babelConfig (config) {
   return {
-    parser: '@babel/eslint-parser',
-    parserOptions: {
-      ...config.parserOptions,
-      requireConfigFile: false
+    languageOptions: {
+      parser: babelParser,
+      parserOptions: {
+        ...config.languageOptions?.parserOptions,
+        requireConfigFile: false
+      }
     },
 
-    plugins: [
+    plugins: {
       ...config.plugins,
-      '@babel/eslint-plugin'
-    ],
+      babelEslintPlugin
+    },
     rules: {
 
       ...config.rules,
@@ -39,47 +46,44 @@ module.exports = function (config) {
       /**
        * Require constructor names to begin with a capital letter.
        *
-       * @see
-       * - https://eslint.org/docs/rules/new-cap
-       * - https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules
+       * @see {@link https://eslint.org/docs/rules/new-cap}
+       * @see {@link https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules}
        */
-      '@babel/new-cap': config.rules['new-cap'] || 'off',
+      '@babel/new-cap': config?.rules?.['new-cap'] || 'off',
 
       /**
        * Disallow `this` keywords outside of classes or class-like objects.
        *
-       * @see
-       * - https://eslint.org/docs/rules/no-invalid-this
-       * - https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules
+       * @see {@link https://eslint.org/docs/rules/no-invalid-this}
+       * @see {@link https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules}
        */
-      '@babel/no-invalid-this': config.rules['no-invalid-this'] || 'off',
+      '@babel/no-invalid-this': config?.rules?.['no-invalid-this'] || 'off',
 
       /**
        * Disallow unused expressions.
        *
-       * @see
-       * - https://eslint.org/docs/rules/no-unused-expressions
-       * - https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules
+       * @see {@link https://eslint.org/docs/rules/no-unused-expressions}
+       * @see {@link https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules}
        */
-      '@babel/no-unused-expressions': config.rules['no-unused-expressions'] || 'off',
+      '@babel/no-unused-expressions':
+        config?.rules?.['no-unused-expressions'] || 'off',
 
       /**
        * Enforce consistent spacing inside braces (🔧 ).
        *
-       * @see
-       * - https://eslint.org/docs/rules/object-curly-spacing
-       * - https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules
+       * @see {@link https://eslint.org/docs/rules/object-curly-spacing}
+       * @see {@link https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules}
        */
-      '@babel/object-curly-spacing': config.rules['object-curly-spacing'] || 'off',
+      '@babel/object-curly-spacing':
+        config?.rules?.['object-curly-spacing'] || 'off',
 
       /**
        * Require or disallow semicolons instead of ASI (🔧).
        *
-       * @see
-       * - https://eslint.org/docs/rules/semi
-       * - https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules
+       * @see {@link https://eslint.org/docs/rules/semi}
+       * @see {@link https://github.com/babel/babel/tree/master/eslint/babel-eslint-plugin#rules}
        */
-      '@babel/semi': config.rules.semi || 'off'
+      '@babel/semi': config?.rules?.semi || 'off'
     }
   };
-};
+}

+modules.js

@@ -1,17 +1,20 @@
-'use strict';
-
-module.exports = {
-  parserOptions: {
-    ecmaFeatures: {globalReturn: false},
-    sourceType: 'module'
-  },
-  globals: {
-    __dirname: 'off',
-    __filename: 'off',
-    exports: 'off',
-    module: 'off',
-    require: 'off'
-  },
+/* eslint-disable jsdoc/imports-as-dependencies -- Bug */
+/** @type {import('eslint').Linter.FlatConfig[]} */
+export default [{
+  languageOptions: {
+    parserOptions: {
+      ecmaFeatures: {globalReturn: false}
+    },
+    sourceType: 'module',
+    globals: {
+      __dirname: 'off',
+      __filename: 'off',
+      exports: 'off',
+      module: 'off',
+      require: 'off'
+    }
+  }
+}, {
   rules: {
     'n/no-unsupported-features/es-syntax': [
       'error',
@@ -21,4 +24,4 @@ module.exports = {
       {ignores: ['modules', 'dynamicImport']}
     ]
   }
-};
+}];

+script-node.js

@@ -1,23 +1,25 @@
-'use strict';
+/* eslint-disable jsdoc/imports-as-dependencies -- Bug */
+import node from 'eslint-plugin-n';
+import globals from 'globals';
 
-// As adding after defaults, recalculate ecmaVersion (Node plugins sets own
-//  `ecmaVersion`)
-const {env, ecmaVersion} = require('./detectEnv.js');
+/** @type {import('eslint').Linter.FlatConfig[]} */
+export default [
+  node.configs['flat/recommended-script'],
+  {
+    languageOptions: {
+      globals: globals.node,
+      parserOptions: {
+        ecmaFeatures: {
+          globalReturn: true
+        }
+      }
+    },
+    rules: {
+      // Allow for Node or Unicorn
+      'no-process-exit': 'off',
 
-module.exports = {
-  env,
-  extends: ['plugin:n/recommended-script'],
-  parserOptions: {
-    ecmaVersion,
-    ecmaFeatures: {
-      globalReturn: true
+      'import/no-commonjs': 'off',
+      strict: ['error']
     }
-  },
-  rules: {
-    // Allow for Node or Unicorn
-    'no-process-exit': 'off',
-
-    'import/no-commonjs': 'off',
-    strict: ['error']
   }
-};
+];

+script.js

@@ -1,14 +1,16 @@
-'use strict';
-
-module.exports = {
-  parserOptions: {
+/* eslint-disable jsdoc/imports-as-dependencies -- Bug */
+/** @type {import('eslint').Linter.FlatConfig[]} */
+export default [{
+  languageOptions: {
     sourceType: 'script',
-    ecmaFeatures: {
-      globalReturn: false
+    parserOptions: {
+      ecmaFeatures: {
+        globalReturn: false
+      }
     }
   },
   rules: {
     'import/no-commonjs': 'off',
     strict: ['error']
   }
-};
+}];

.ncurc.cjs

@@ -0,0 +1,8 @@
+'use strict';
+
+module.exports = {
+  reject: [
+    // todo[engine:node@>=20]
+    'rimraf'
+  ]
+};

.npmignore

@@ -1 +1,4 @@
 pnpm-lock.yaml
+eslint.config.js
+inherited-rules/build.js
+typings

README.md

@@ -14,29 +14,19 @@ install-peerdeps -d eslint-config-ash-nazg
 
 ## The rules
 
-See [index.js](./index.js) (and [node.js](./node.js) for `ash-nazg/node`
+See [main.js](./main.js) (and [node.js](./node.js) for `ash-nazg/node`
 rules) for the rules we explicitly include (and see
 [sauron.js](./sauron.js) for the even stricter `ash-nazg/sauron` rules or
 [great-eye](./great-eye.js) (or [great-eye-node](./great-eye-node.js)) for
 still stricter rules though which are probably best not used).
 
-`env` is set to automatically include `'shared-node-browser': true` given that
-most environments will be Node or a browser or a polyglot Node-browser. If you
-really don't want this, you can override by setting
-`'shared-node-browser': false`. Note that this setting only adds globals which
-are present in either Node or the browser; it won't falsely allow browser
-globals in a Node app or vice versa; you can use `env`'s `node: true` or
-`browser: true` if you want to support Node or browser globals.
-
 (See [explicitly-unused.js](./explicitly-unused.js) for the core and extended
 rules we don't include (rationale for non-inclusion below).)
 
 - [Main rules](https://eslint.org/docs/rules/) (also search for "error" within `eslint-recommended.js` of `@eslint/js`) for the `eslint:recommended` rules we inherit (though see below for our two modifications to these).
 - ["standard"](https://github.com/standard/eslint-config-standard/blob/master/eslintrc.json)
 rules we inherit (though see below for our handful of modifications).
-- [@brettz9/eslint-plugin](https://github.com/brettz9/eslint-plugin)
-    for a number of added rules
-- [eslint-comments/recommended](https://github.com/mysticatea/eslint-plugin-eslint-comments)
+- [eslint-comments/recommended](https://github.com/eslint-community/eslint-plugin-eslint-comments)
 - [eslint-plugin-no-use-extend-native](https://github.com/dustinspecker/eslint-plugin-no-use-extend-native) for one added rule.
 - [eslint-plugin-no-unsanitized](https://github.com/mozilla/eslint-plugin-no-unsanitized) for two added rules.
 - [Recommended Unicorn rules](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/master/index.js#L20-L53) (a few items disabled and enabled as per below)
@@ -126,12 +116,12 @@ typically inheriting "recommended" configs), see
 `/inherited-rules/implicitly-included`.
 
 To see which rules from the extended config we disabled, see our relevant
-config(s) (e.g., `index.js`).
+config(s) (e.g., `main.js`).
 
 To see which rules from the plugin that each extended config derives from
 (i.e., the non-recommended rules of a plug-in), see `explicitly-unused.js`
 for ones we have consciously not used and see our relevant config(s)
-(e.g., `index.js`) for the ones we did add (alongside any recommended).
+(e.g., `main.js`) for the ones we did add (alongside any recommended).
 
 The `unused` folder is used to capture any (non-recommended) rules which
 are not explicitly either enabled or within `explicitly-unused.js` (as
@@ -406,15 +396,15 @@ appears, to Dark Lords.
 
 `promise/no-nesting` - can be useful to nest sometimes
 
-`promise/no-promise-in-callback` - May be difficult to apply (Note: Is disabled in `index.js` but enabled in `sauron.js`)
+`promise/no-promise-in-callback` - May be difficult to apply (Note: Is disabled in `main.js` but enabled in `sauron.js`)
 
-`promise/no-callback-in-promise` - May be difficult to apply (Note: Is disabled in `index.js` but enabled in `sauron.js`)
+`promise/no-callback-in-promise` - May be difficult to apply (Note: Is disabled in `main.js` but enabled in `sauron.js`)
 
-`promise/avoid-new` - Can be useful or even necessary for APIs missing Promise version (Note: Is disabled in `index.js` but enabled in `sauron.js`; could use `promisify`)
+`promise/avoid-new` - Can be useful or even necessary for APIs missing Promise version (Note: Is disabled in `main.js` but enabled in `sauron.js`; could use `promisify`)
 
-`promise/no-return-in-finally` - (Note: Is disabled in `index.js` but enabled in `sauron.js`)
+`promise/no-return-in-finally` - (Note: Is disabled in `main.js` but enabled in `sauron.js`)
 
-`promise/valid-params` - (Note: Is disabled in `index.js` but enabled in `sauron.js`)
+`promise/valid-params` - (Note: Is disabled in `main.js` but enabled in `sauron.js`)
 
 #### Rationale for suppressing some `eslint-plugin-jsdoc` rules
 
@@ -537,18 +527,6 @@ appears, to Dark Lords.
 - `eslint-comments/no-restricted-disable` - See no need
 - `eslint-comments/no-use` - See no need
 
-### Rationale for not including some `plugin:@brettz9/es6` rules
-
-- `@brettz9/arrow-parens` - Covered by other rules
-- `@brettz9/no-instanceof-array` - Covered by our blocking of all
-    `instanceof`
-- `@brettz9/no-instanceof-wrapper` - Covered by our blocking of all
-    `instanceof`
-- `@brettz9/prefer-for-of` - I prefer array extras for easier reuse,
-    currying, etc. than `for-of`
-- `@brettz9/no-use-ignored-vars` - Relies on a regex (for pseudo-privates)
-    which can be useful
-
 ### Rationale for not including some `array-func` rules
 
 - `array-func/prefer-array-from` - While it may benefit performance, it is
@@ -711,6 +689,10 @@ The `preferredTypes` setting was enabled here for integer/float as it can
 be cumbersome for projects to distinguish and because `Promise` even
 subclassed doesn't indicate the rejector type.
 
+## Rationale for not including some rules in @brettz9/eslint-plugin
+
+- `@brettz9/for-of` - Iterating functions can be easier to refactor
+
 ## Rationale for including rules that might not seem necessary
 
 - `no-implicit-globals` - Included despite not applying to modules, in

browser.js

@@ -0,0 +1,11 @@
+/* eslint-disable jsdoc/imports-as-dependencies -- Bug */
+import eslintCompat from 'eslint-plugin-compat';
+// import esCompat from 'eslint-plugin-escompat'; // Todo: Waiting on https://github.com/keithamus/eslint-plugin-escompat/pull/24
+// import noUnsanitized from 'eslint-plugin-no-unsanitized'; // Todo: Disable until https://github.com/mozilla/eslint-plugin-no-unsanitized/pull/239#issuecomment-2132867450
+
+/** @type {import('eslint').Linter.FlatConfig[]} */
+export default [
+  eslintCompat.configs['flat/recommended']
+  // esCompat.configs['flat/recommended]
+  // noUnsanitized.DOM,
+];