feat: start TypeScript migration (#42)

.changeset/wicked-schools-stare.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-import-x": minor
+---
+
+feat!: start TypeScript migration

.eslintrc.js

@@ -1,3 +1,6 @@
+/**
+ * @type {import('eslint').Linter.Config}
+ */
 module.exports = {
   root: true,
   plugins: ['eslint-plugin', 'import-x'],
@@ -18,6 +21,7 @@ module.exports = {
     ecmaVersion: 2020,
   },
   rules: {
+    '@typescript-eslint/no-non-null-assertion': 'off',
     '@typescript-eslint/no-var-requires': 'off',
 
     'eslint-plugin/consistent-output': ['error', 'always'],
@@ -55,6 +59,15 @@ module.exports = {
   },
 
   overrides: [
+    {
+      files: ['*.js', '*.ts'],
+      excludedFiles: ['test/fixtures'],
+      settings: {
+        'import-x/resolver': {
+          typescript: true,
+        },
+      },
+    },
     {
       files: 'test/**',
       env: {

babel.config.js

@@ -1,3 +1,6 @@
+/**
+ * @type {import('@babel/core').TransformOptions}
+ */
 module.exports = {
   presets: [
     [
@@ -22,4 +25,10 @@ module.exports = {
   ],
   sourceMaps: 'inline',
   retainLines: true,
+  overrides: [
+    {
+      include: '**/*.ts',
+      presets: ['@babel/typescript'],
+    },
+  ],
 }

jest.config.js

@@ -1,19 +1,23 @@
+const testCompiled = process.env.TEST_COMPILED === '1'
+
+const srcDir = testCompiled ? 'lib' : 'src'
+
 /**
  * @type {import('@jest/types').Config.InitialOptions}
  */
 module.exports = {
-  collectCoverage: true,
+  collectCoverage: !testCompiled,
   modulePathIgnorePatterns: ['<rootDir>/test/fixtures/with-syntax-error'],
   moduleNameMapper: {
-    '^core/(.+)$': '<rootDir>/src/core/$1',
-    '^eslint-plugin-import-x$': '<rootDir>/src/index.js',
-    '^eslint-plugin-import-x/config/(.+)$': '<rootDir>/config/$1',
+    '^core/(.+)$': `<rootDir>/${srcDir}/core/$1`,
+    '^eslint-plugin-import-x$': `<rootDir>/${srcDir}`,
     '^eslint-plugin-import-x/package.json$': '<rootDir>/package.json',
-    '^eslint-plugin-import-x/(.+)$': '<rootDir>/src/$1',
-    '^rules/(.+)$': '<rootDir>/src/rules/$1',
+    '^eslint-plugin-import-x/(.+)$': `<rootDir>/${srcDir}/$1`,
+    '^rules/(.+)$': `<rootDir>/${srcDir}/rules/$1`,
   },
   testMatch: [
     '<rootDir>/test/**/*.spec.js',
+    '<rootDir>/test/**/*.spec.ts',
     '!<rootDir>/test/fixtures/**/*.js',
   ],
 }

package.json

@@ -12,13 +12,12 @@
   "main": "lib/index.js",
   "exports": {
     ".": "./lib/index.js",
-    "./config/*": "./config/*",
     "./package.json": "./package.json",
     "./*": "./lib/*"
   },
   "files": [
-    "config",
-    "lib"
+    "lib",
+    "!lib/*.tsbuildinfo"
   ],
   "keywords": [
     "eslint",
@@ -31,19 +30,21 @@
     "export"
   ],
   "scripts": {
-    "build": "babel --quiet --out-dir lib src",
+    "build": "rimraf lib && tsc -p src",
     "lint": "yarn lint:es && yarn update:eslint-docs --check",
     "lint:es": "eslint . --cache",
-    "prebuild": "rimraf lib",
+    "prepare": "patch-package",
     "release": "changeset publish",
     "test": "jest",
+    "test-compiled": "yarn build && cross-env TEST_COMPILED=1 jest",
     "update:eslint-docs": "yarn build && eslint-doc-generator --rule-doc-title-format prefix-name --rule-doc-section-options false --rule-list-split meta.docs.category --ignore-config stage-0 --config-emoji recommended,☑️",
     "watch": "yarn test --watch"
   },
   "peerDependencies": {
     "eslint": "^7.2.0 || ^8"
   },
   "dependencies": {
+    "@typescript-eslint/utils": "^5.62.0",
     "debug": "^4.3.4",
     "doctrine": "^3.0.0",
     "eslint-import-resolver-node": "^0.3.9",
@@ -54,23 +55,30 @@
   },
   "devDependencies": {
     "@1stg/prettier-config": "^4.0.1",
+    "@1stg/tsconfig": "^2.3.3",
     "@angular-eslint/template-parser": "^17.2.1",
-    "@babel/cli": "^7.23.9",
     "@babel/core": "^7.24.0",
     "@babel/eslint-parser": "^7.23.10",
     "@babel/plugin-proposal-decorators": "^7.24.0",
     "@babel/plugin-proposal-export-default-from": "^7.23.3",
     "@babel/preset-env": "^7.24.0",
     "@babel/preset-flow": "^7.24.0",
     "@babel/preset-react": "^7.23.3",
+    "@babel/preset-typescript": "^7.23.3",
     "@babel/register": "^7.23.7",
     "@changesets/changelog-github": "^0.5.0",
     "@changesets/cli": "^2.27.1",
     "@eslint/import-test-order-redirect-scoped": "link:./test/fixtures/order-redirect-scoped",
     "@test-scope/some-module": "link:./test/fixtures/symlinked-module",
+    "@types/eslint": "^8.56.5",
     "@types/jest": "^29.5.12",
-    "@typescript-eslint/eslint-plugin": "^7.2.0",
+    "@types/json-schema": "^7.0.15",
+    "@typescript-eslint/eslint-plugin": "^5.62.0",
     "@typescript-eslint/parser": "^5.62.0",
+    "@typescript-eslint/typescript-estree": "^5.62.0",
+    "@unts/patch-package": "^8.0.0",
+    "cross-env": "^7.0.3",
+    "enhanced-resolve": "^5.16.0",
     "escope": "^4.0.0",
     "eslint": "^7.2.0 || ^8",
     "eslint-config-prettier": "^9.1.0",
@@ -88,6 +96,7 @@
     "redux": "^5.0.1",
     "rimraf": "^5.0.5",
     "svelte": "^4.2.12",
-    "typescript": "^5.4.2"
+    "type-fest": "^4.12.0",
+    "typescript": "~5.1.0"
   }
 }

patches/@typescript-eslint+utils+5.62.0.patch

@@ -0,0 +1,15 @@
+diff --git a/node_modules/@typescript-eslint/utils/dist/ts-eslint/Rule.d.ts b/node_modules/@typescript-eslint/utils/dist/ts-eslint/Rule.d.ts
+index 9a3a1fd..46b3961 100644
+--- a/node_modules/@typescript-eslint/utils/dist/ts-eslint/Rule.d.ts
++++ b/node_modules/@typescript-eslint/utils/dist/ts-eslint/Rule.d.ts
+@@ -6,6 +6,10 @@ import type { Scope } from './Scope';
+ import type { SourceCode } from './SourceCode';
+ export type RuleRecommendation = 'error' | 'strict' | 'warn' | false;
+ interface RuleMetaDataDocs {
++    /**
++     * The category the rule falls under
++     */
++    category?: string;
+     /**
+      * Concise description of the rule
+      */

src/ExportMap.js

@@ -9,7 +9,7 @@ import { SourceCode } from 'eslint'
 
 import parse from './utils/parse'
 import visit from './utils/visit'
-import resolve from './utils/resolve'
+import { relative, resolve } from './utils/resolve'
 import isIgnored, { hasValidExtension } from './utils/ignore'
 
 import { hashObject } from './utils/hash'
@@ -506,7 +506,7 @@ ExportMap.parse = function (path, content, context) {
   const namespaces = new Map()
 
   function remotePath(value) {
-    return resolve.relative(value, path, context.settings)
+    return relative(value, path, context.settings)
   }
 
   function resolveImport(value) {

config/electron.js → src/config/electron.ts

@@ -1,8 +1,10 @@
+import type { PluginConfig } from '../types'
+
 /**
  * Default settings for Electron applications.
  */
-module.exports = {
+export = {
   settings: {
     'import-x/core-modules': ['electron'],
   },
-}
+} satisfies PluginConfig

config/errors.js → src/config/errors.ts

@@ -1,9 +1,10 @@
+import type { PluginConfig } from '../types'
+
 /**
  * unopinionated config. just the things that are necessarily runtime errors
  * waiting to happen.
- * @type {Object}
  */
-module.exports = {
+export = {
   plugins: ['import-x'],
   rules: {
     'import-x/no-unresolved': 2,
@@ -12,4 +13,4 @@ module.exports = {
     'import-x/default': 2,
     'import-x/export': 2,
   },
-}
+} satisfies PluginConfig

config/react-native.js → src/config/react-native.ts

@@ -1,7 +1,9 @@
+import type { PluginConfig } from '../types'
+
 /**
- * - adds platform extensions to Node resolver
+ * adds platform extensions to Node resolver
  */
-module.exports = {
+export = {
   settings: {
     'import-x/resolver': {
       node: {
@@ -10,4 +12,4 @@ module.exports = {
       },
     },
   },
-}
+} satisfies PluginConfig

config/react.js → src/config/react.ts

@@ -1,16 +1,19 @@
+import type { PluginConfig } 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.
  */
-module.exports = {
+export = {
   settings: {
     'import-x/extensions': ['.js', '.jsx'],
   },
-
   parserOptions: {
-    ecmaFeatures: { jsx: true },
+    ecmaFeatures: {
+      jsx: true,
+    },
   },
-}
+} satisfies PluginConfig

config/recommended.js → src/config/recommended.ts

@@ -1,8 +1,9 @@
+import type { PluginConfig } from '../types'
+
 /**
  * The basics.
- * @type {Object}
  */
-module.exports = {
+export = {
   plugins: ['import-x'],
 
   rules: {
@@ -25,4 +26,4 @@ module.exports = {
     sourceType: 'module',
     ecmaVersion: 2018,
   },
-}
+} satisfies PluginConfig

config/stage-0.js → src/config/stage-0.ts

@@ -1,12 +1,13 @@
+import type { PluginConfig } from '../types'
+
 /**
  * Rules in progress.
  *
  * Do not expect these to adhere to semver across releases.
- * @type {Object}
  */
-module.exports = {
+export = {
   plugins: ['import-x'],
   rules: {
     'import-x/no-deprecated': 1,
   },
-}
+} as PluginConfig

config/typescript.js → src/config/typescript.ts

@@ -1,3 +1,5 @@
+import type { PluginConfig } from '../types'
+
 /**
  * This config:
  * 1) adds `.jsx`, `.ts`, `.cts`, `.mts`, and `.tsx` as an extension
@@ -7,28 +9,27 @@
 // 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', '.cts', '.mts', '.tsx']
+const typeScriptExtensions = ['.ts', '.tsx'] as const
 
-const allExtensions = [...typeScriptExtensions, '.js', '.jsx']
+const allExtensions = [...typeScriptExtensions, '.js', '.jsx'] as const
 
-module.exports = {
+export = {
   settings: {
     'import-x/extensions': allExtensions,
     'import-x/external-module-folders': ['node_modules', 'node_modules/@types'],
     'import-x/parsers': {
-      '@typescript-eslint/parser': typeScriptExtensions,
+      '@typescript-eslint/parser': [...typeScriptExtensions, '.cts', '.mts'],
     },
     '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 PluginConfig

config/warnings.js → src/config/warnings.ts

@@ -1,12 +1,13 @@
+import type { PluginConfig } from '../types'
+
 /**
  * more opinionated config.
- * @type {Object}
  */
-module.exports = {
+export = {
   plugins: ['import-x'],
   rules: {
     'import-x/no-named-as-default': 1,
     'import-x/no-named-as-default-member': 1,
     'import-x/no-duplicates': 1,
   },
-}
+} satisfies PluginConfig