feat: add flat config presets (#122)

Co-authored-by: Sukka <isukkaw@gmail.com>

Author: michaelfaith

.changeset/great-dodos-dream.md

@@ -0,0 +1,14 @@
+---
+"eslint-plugin-import-x": minor
+---
+
+Add ESLint flat configuration presets. You can access them with:
+
+```ts
+import eslintPluginImportX from 'eslint-plugin-import-x';
+
+eslintPluginImportX.flatConfigs.recommended;
+eslintPluginImportX.flatConfigs.react;
+eslintPluginImportX.flatConfigs.typescript;
+eslintPluginImportX.flatConfigs.electron;
+```

package.json

@@ -35,7 +35,7 @@
     "codesandbox:install": "yarn --ignore-engines",
     "lint": "run-p lint:*",
     "lint:docs": "yarn update:eslint-docs --check",
-    "lint:es": "ESLINT_USE_FLAT_CONFIG=false eslint . --cache",
+    "lint:es": "cross-env ESLINT_USE_FLAT_CONFIG=false eslint . --cache",
     "lint:tsc": "tsc -p tsconfig.base.json --noEmit",
     "prepare": "patch-package",
     "release": "changeset publish",

src/config/flat/electron.ts

@@ -0,0 +1,10 @@
+import type { PluginFlatConfig } from '../../types'
+
+/**
+ * Default settings for Electron applications.
+ */
+export default {
+  settings: {
+    'import-x/core-modules': ['electron'],
+  },
+} satisfies PluginFlatConfig

src/config/flat/errors.ts

@@ -0,0 +1,15 @@
+import type { PluginFlatConfig } from '../../types'
+
+/**
+ * unopinionated config. just the things that are necessarily runtime errors
+ * waiting to happen.
+ */
+export default {
+  rules: {
+    'import-x/no-unresolved': 2,
+    'import-x/named': 2,
+    'import-x/namespace': 2,
+    'import-x/default': 2,
+    'import-x/export': 2,
+  },
+} satisfies PluginFlatConfig

src/config/flat/react-native.ts

@@ -0,0 +1,15 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * adds platform extensions to Node resolver
+ */
+export default {
+  settings: {
+    'import-x/resolver': {
+      node: {
+        // Note: will not complain if only _one_ of these files exists.
+        extensions: ['.js', '.web.js', '.ios.js', '.android.js'],
+      },
+    },
+  },
+} satisfies PluginFlatBaseConfig

src/config/flat/react.ts

@@ -0,0 +1,21 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * Adds `.jsx` as an extension, and enables JSX parsing.
+ *
+ * Even if _you_ aren't using JSX (or .jsx) directly, if your dependencies
+ * define jsnext:main and have JSX internally, you may run into problems
+ * if you don't enable these settings at the top level.
+ */
+export default {
+  settings: {
+    'import-x/extensions': ['.js', '.jsx', '.mjs', '.cjs'],
+  },
+  languageOptions: {
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
+      },
+    },
+  },
+} satisfies PluginFlatBaseConfig

src/config/flat/recommended.ts

@@ -0,0 +1,27 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * The basics.
+ */
+export default {
+  rules: {
+    // analysis/correctness
+    'import-x/no-unresolved': 'error',
+    'import-x/named': 'error',
+    'import-x/namespace': 'error',
+    'import-x/default': 'error',
+    'import-x/export': 'error',
+
+    // red flags (thus, warnings)
+    'import-x/no-named-as-default': 'warn',
+    'import-x/no-named-as-default-member': 'warn',
+    'import-x/no-duplicates': 'warn',
+  },
+
+  // need all these for parsing dependencies (even if _your_ code doesn't need
+  // all of them)
+  languageOptions: {
+    ecmaVersion: 2018,
+    sourceType: 'module',
+  },
+} satisfies PluginFlatBaseConfig

src/config/flat/stage-0.ts

@@ -0,0 +1,12 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * Rules in progress.
+ *
+ * Do not expect these to adhere to semver across releases.
+ */
+export default {
+  rules: {
+    'import-x/no-deprecated': 1,
+  },
+} satisfies PluginFlatBaseConfig

src/config/flat/typescript.ts

@@ -0,0 +1,41 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * This config:
+ * 1) adds `.jsx`, `.ts`, `.cts`, `.mts`, and `.tsx` as an extension
+ * 2) enables JSX/TSX parsing
+ */
+
+// Omit `.d.ts` because 1) TypeScript compilation already confirms that
+// types are resolved, and 2) it would mask an unresolved
+// `.ts`/`.tsx`/`.js`/`.jsx` implementation.
+const typeScriptExtensions = ['.ts', '.tsx', '.cts', '.mts'] as const
+
+const allExtensions = [
+  ...typeScriptExtensions,
+  '.js',
+  '.jsx',
+  '.cjs',
+  '.mjs',
+] as const
+
+export default {
+  settings: {
+    'import-x/extensions': allExtensions,
+    'import-x/external-module-folders': ['node_modules', 'node_modules/@types'],
+    'import-x/parsers': {
+      '@typescript-eslint/parser': [...typeScriptExtensions],
+    },
+    'import-x/resolver': {
+      node: {
+        extensions: allExtensions,
+      },
+    },
+  },
+  rules: {
+    // analysis/correctness
+
+    // TypeScript compilation already ensures that named imports exist in the referenced module
+    'import-x/named': 'off',
+  },
+} satisfies PluginFlatBaseConfig

src/config/flat/warnings.ts

@@ -0,0 +1,12 @@
+import type { PluginFlatBaseConfig } from '../../types'
+
+/**
+ * more opinionated config.
+ */
+export default {
+  rules: {
+    'import-x/no-named-as-default': 1,
+    'import-x/no-named-as-default-member': 1,
+    'import-x/no-duplicates': 1,
+  },
+} satisfies PluginFlatBaseConfig