feat: implement import-x resolver interface v3

.changeset/metal-insects-trade.md

@@ -0,0 +1,45 @@
+---
+'eslint-import-resolver-typescript': minor
+---
+
+This version has implemented the `eslint-plugin-import-x`'s v3 resolver interface. This allows you to use import/require to reference `eslint-import-resolver-typescript` directly in your ESLint flat config:
+
+**Previously**
+
+```js
+// eslint.config.js
+module.exports = {
+  settings: {
+    'import-x/resolver': {
+      typescript: {
+        alwaysTryTypes: true,
+      },
+      // or
+      require.resolve('eslint-import-resolver-typescript'):
+        alwaysTryTypes: true,
+      }
+    }
+  }
+}
+```
+
+**Now**
+
+```js
+// eslint.config.js
+const {
+  createTypeScriptImportResolver,
+} = require('eslint-import-resolver-typescript')
+
+module.exports = {
+  settings: {
+    'import-x/resolver-next': [
+      createTypeScriptImportResolver({
+        alwaysTryTypes: true,
+      }),
+    ],
+  },
+}
+```
+
+Note that this only works with `eslint-plugin-import-x@>=4.5.0`. You can't use `createTypeScriptImportResolver` with the older versions of `eslint-plugin-import-x` or any existing versions of `eslint-plugin-import`.

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "eslint.useFlatConfig": false
+}

README.md

@@ -62,6 +62,90 @@ yarn add -D eslint-plugin-import eslint-import-resolver-typescript
 
 ## Configuration
 
+### `eslint.config.js`
+
+If you are using `eslint-plugin-import-x@>=4.5.0`, you can use import/require to reference `eslint-import-resolver-typescript` directly in your ESLint flat config:
+
+```js
+// eslint.config.js
+const {
+  createTypeScriptImportResolver,
+} = require('eslint-import-resolver-typescript')
+
+module.exports = [{
+  settings: {
+    "import/resolver-next": [
+      createTypeScriptImportResolver({
+        alwaysTryTypes: true, // always try to resolve types under `<root>@types` directory even it doesn't contain any source code, like `@types/unist`
+
+        // Choose from one of the "project" configs below or omit to use <root>/tsconfig.json by default
+
+        // use <root>/path/to/folder/tsconfig.json
+        project: "path/to/folder",
+
+        // Multiple tsconfigs (Useful for monorepos)
+
+        // use a glob pattern
+        project: "packages/*/tsconfig.json",
+
+        // use an array
+        project: [
+          "packages/module-a/tsconfig.json",
+          "packages/module-b/tsconfig.json"
+        ],
+
+        // use an array of glob patterns
+        project: [
+          "packages/*/tsconfig.json",
+          "other-packages/*/tsconfig.json"
+        ]
+      }),
+    ];
+  }
+}]
+```
+
+But if you are using `eslint-plugin-import` or the older version of `eslint-plugin-import-x`, you can't use require/import:
+
+```js
+// eslint.config.js
+module.exports = [
+  {
+    settings: {
+      'import/resolvers': {
+        typescript: {
+          alwaysTryTypes: true, // always try to resolve types under `<root>@types` directory even it doesn't contain any source code, like `@types/unist`
+
+          // Choose from one of the "project" configs below or omit to use <root>/tsconfig.json by default
+
+          // use <root>/path/to/folder/tsconfig.json
+          project: 'path/to/folder',
+
+          // Multiple tsconfigs (Useful for monorepos)
+
+          // use a glob pattern
+          project: 'packages/*/tsconfig.json',
+
+          // use an array
+          project: [
+            'packages/module-a/tsconfig.json',
+            'packages/module-b/tsconfig.json',
+          ],
+
+          // use an array of glob patterns
+          project: [
+            'packages/*/tsconfig.json',
+            'other-packages/*/tsconfig.json',
+          ],
+        },
+      },
+    },
+  },
+]
+```
+
+### `.eslintrc`
+
 Add the following to your `.eslintrc` config:
 
 ```jsonc

package.json

@@ -51,6 +51,7 @@
     "prepare": "simple-git-hooks",
     "release": "changeset publish",
     "test": "run-p 'test:*'",
+    "test:importXResolverV3": "eslint --config=tests/importXResolverV3/eslint.config.js tests/importXResolverV3",
     "test:multipleEslintrcs": "eslint --ext ts,tsx tests/multipleEslintrcs",
     "test:multipleTsconfigs": "eslint --ext ts,tsx tests/multipleTsconfigs",
     "test:withJsExtension": "node tests/withJsExtension/test.js && eslint --ext ts,tsx tests/withJsExtension",
@@ -78,13 +79,14 @@
     "@nolyfill/is-core-module": "1.0.39",
     "debug": "^4.3.7",
     "enhanced-resolve": "^5.15.0",
-    "eslint-module-utils": "^2.8.1",
     "fast-glob": "^3.3.2",
     "get-tsconfig": "^4.7.5",
     "is-bun-module": "^1.0.2",
-    "is-glob": "^4.0.3"
+    "is-glob": "^4.0.3",
+    "stable-hash": "^0.0.4"
   },
   "devDependencies": {
+    "@1stg/eslint-config": "7",
     "@1stg/lib-config": "^12.0.1",
     "@changesets/changelog-github": "^0.5.0",
     "@changesets/cli": "^2.27.10",
@@ -99,6 +101,7 @@
     "eslint": "^8.57.1",
     "eslint-import-resolver-typescript": "link:.",
     "eslint-plugin-import": "npm:eslint-plugin-i@^2.29.1",
+    "eslint-plugin-import-x": "^4.5.0",
     "lint-staged": "^13.3.0",
     "npm-run-all2": "^5.0.2",
     "prettier": "^2.8.8",

src/index.ts

@@ -5,16 +5,19 @@ import isNodeCoreModule from '@nolyfill/is-core-module'
 import debug from 'debug'
 import type { FileSystem, ResolveOptions, Resolver } from 'enhanced-resolve'
 import enhancedResolve from 'enhanced-resolve'
-import { hashObject } from 'eslint-module-utils/hash.js'
 import fg from 'fast-glob'
 import { createPathsMatcher, getTsconfig } from 'get-tsconfig'
 import type { TsConfigResult } from 'get-tsconfig'
 import type { Version } from 'is-bun-module'
 import { isBunModule } from 'is-bun-module'
 import isGlob from 'is-glob'
+import stableHashExports from 'stable-hash'
 
 const { globSync } = fg
 
+// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition -- esmodule interop
+const stableHash = stableHashExports.default || stableHashExports
+
 const IMPORTER_NAME = 'eslint-import-resolver-typescript'
 
 const log = debug(IMPORTER_NAME)
@@ -114,10 +117,7 @@ let mappersCachedOptions: InternalResolverOptions
 let mappers: Array<((specifier: string) => string[]) | null> | undefined
 
 let resolverCachedOptions: InternalResolverOptions
-let resolver: Resolver | undefined
-
-const digestHashObject = (value: object | null | undefined) =>
-  hashObject(value ?? {}).digest('hex')
+let cachedResolver: Resolver | undefined
 
 /**
  * @param source the module to resolve; i.e './some-module'
@@ -129,13 +129,14 @@ export function resolve(
   source: string,
   file: string,
   options?: TsResolverOptions | null,
+  resolver: Resolver | null = null,
 ): {
   found: boolean
   path?: string | null
 } {
   if (
     !cachedOptions ||
-    previousOptionsHash !== (optionsHash = digestHashObject(options))
+    previousOptionsHash !== (optionsHash = stableHash(options))
   ) {
     previousOptionsHash = optionsHash
     cachedOptions = {
@@ -152,9 +153,13 @@ export function resolve(
     }
   }
 
-  if (!resolver || resolverCachedOptions !== cachedOptions) {
-    resolver = enhancedResolve.ResolverFactory.createResolver(cachedOptions)
-    resolverCachedOptions = cachedOptions
+  if (!resolver) {
+    if (!cachedResolver || resolverCachedOptions !== cachedOptions) {
+      cachedResolver =
+        enhancedResolve.ResolverFactory.createResolver(cachedOptions)
+      resolverCachedOptions = cachedOptions
+    }
+    resolver = cachedResolver
   }
 
   log('looking for:', source)
@@ -229,6 +234,28 @@ export function resolve(
   }
 }
 
+export function createTypeScriptImportResolver(
+  options?: TsResolverOptions | null,
+) {
+  const resolver = enhancedResolve.ResolverFactory.createResolver({
+    ...options,
+    conditionNames: options?.conditionNames ?? defaultConditionNames,
+    extensions: options?.extensions ?? defaultExtensions,
+    extensionAlias: options?.extensionAlias ?? defaultExtensionAlias,
+    mainFields: options?.mainFields ?? defaultMainFields,
+    fileSystem: new enhancedResolve.CachedInputFileSystem(fileSystem, 5 * 1000),
+    useSyncFileSystemCalls: true,
+  })
+
+  return {
+    interfaceVersion: 3,
+    name: IMPORTER_NAME,
+    resolve(source: string, file: string) {
+      return resolve(source, file, options, resolver)
+    },
+  }
+}
+
 /** Remove any trailing querystring from module id. */
 function removeQuerystring(id: string) {
   const querystringIndex = id.lastIndexOf('?')

tests/importXResolverV3/eslint.config.js

@@ -0,0 +1,20 @@
+const path = require('path')
+const { createTypeScriptImportResolver } = require('../../lib/index.cjs')
+
+const globPattern = './packages/*/tsconfig.json'
+
+// in normal cases this is not needed because the __dirname would be the root
+const absoluteGlobPath = path.join(__dirname, globPattern)
+
+module.exports = {
+  ...require('eslint-plugin-import-x').flatConfigs.typescript,
+  settings: {
+    ...require('eslint-plugin-import-x').flatConfigs.typescript.settings,
+    'import-x/resolver-next': [
+      createTypeScriptImportResolver({
+        project: absoluteGlobPath,
+        alwaysTryTypes: true,
+      }),
+    ],
+  },
+}

tests/importXResolverV3/packages/module-a/index.ts

@@ -0,0 +1,15 @@
+// import relative
+import './tsImportee'
+import './tsxImportee'
+import './subfolder/tsImportee'
+import './subfolder/tsxImportee'
+
+// import using tsconfig.json path mapping
+import 'folder/tsImportee'
+import 'folder/tsxImportee'
+import 'folder/subfolder/tsImportee'
+import 'folder/subfolder/tsxImportee'
+
+// import from node_module
+import 'typescript'
+import 'dummy.js'

tests/importXResolverV3/packages/module-a/subfolder/tsImportee.ts

@@ -0,0 +1 @@
+export default 'yes'

tests/importXResolverV3/packages/module-a/subfolder/tsxImportee.tsx

@@ -0,0 +1 @@
+export default 'React Component'

tests/importXResolverV3/packages/module-a/tsImportee.ts

@@ -0,0 +1 @@
+export default 'yes'

tests/importXResolverV3/packages/module-a/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "jsx": "react",
+    "paths": {
+      "folder/*": ["*"],
+      "*": ["../../../../node_modules/*"]
+    }
+  },
+  "files": ["index.ts", "tsImportee.ts", "tsxImportee.tsx"]
+}

tests/importXResolverV3/packages/module-a/tsxImportee.tsx

@@ -0,0 +1 @@
+export default 'React Component'

tests/importXResolverV3/packages/module-b/index.ts

@@ -0,0 +1,15 @@
+// import relative
+import './tsImportee'
+import './tsxImportee'
+import './subfolder/tsImportee'
+import './subfolder/tsxImportee'
+
+// import using tsconfig.json path mapping
+import 'folder/tsImportee'
+import 'folder/tsxImportee'
+import 'folder/subfolder/tsImportee'
+import 'folder/subfolder/tsxImportee'
+
+// import from node_module
+import 'typescript'
+import 'dummy.js'

tests/importXResolverV3/packages/module-b/subfolder/tsImportee.ts

@@ -0,0 +1 @@
+export default 'yes'

tests/importXResolverV3/packages/module-b/subfolder/tsxImportee.tsx

@@ -0,0 +1 @@
+export default 'React Component'

tests/importXResolverV3/packages/module-b/tsImportee.ts

@@ -0,0 +1 @@
+export default 'yes'

tests/importXResolverV3/packages/module-b/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "jsx": "react",
+    "paths": {
+      "folder/*": ["*"],
+      "*": ["../../../../node_modules/*"]
+    }
+  },
+  "files": ["index.ts", "tsImportee.ts", "tsxImportee.tsx"]
+}

tests/importXResolverV3/packages/module-b/tsxImportee.tsx

@@ -0,0 +1 @@
+export default 'React Component'

tsconfig.json

@@ -6,5 +6,5 @@
     "allowSyntheticDefaultImports": true,
     "esModuleInterop": true
   },
-  "include": ["./src", "./shim.d.ts"]
+  "include": ["./src"]
 }