feat: map legacy node resolver to the new one with fallback support

.changeset/khaki-sites-teach.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-import-x": minor
+---
+
+feat: map legacy node resolver to the new one with fallback support

.github/workflows/ci.yml

@@ -29,7 +29,11 @@ jobs:
 
         include:
           - executeLint: true
-            node: 22
+            node: lts/*
+            eslint: 9
+            os: ubuntu-latest
+          - noLegacyNodeResolver: true
+            node: lts/*
             eslint: 9
             os: ubuntu-latest
       fail-fast: false
@@ -53,6 +57,10 @@ jobs:
       - name: Install Dependencies
         run: yarn --immutable
 
+      - name: Uninstall Legacy Node Resolver
+        if: ${{ matrix.noLegacyNodeResolver }}
+        run: yarn remove eslint-import-resolver-node
+
       - name: Build and Test
         run: yarn run-s test-compiled test
 

package.json

@@ -64,14 +64,19 @@
     "watch": "yarn test --watch"
   },
   "peerDependencies": {
-    "eslint": "^8.57.0 || ^9.0.0"
+    "eslint": "^8.57.0 || ^9.0.0",
+    "eslint-import-resolver-node": "*"
+  },
+  "peerDependenciesMeta": {
+    "eslint-import-resolver-node": {
+      "optional": true
+    }
   },
   "dependencies": {
     "@typescript-eslint/utils": "^8.32.1",
     "comment-parser": "^1.4.1",
     "debug": "^4.4.1",
-    "eslint-import-context": "^0.1.5",
-    "eslint-import-resolver-node": "^0.3.9",
+    "eslint-import-context": "^0.1.6",
     "is-glob": "^4.0.3",
     "minimatch": "^9.0.3 || ^10.0.1",
     "semver": "^7.7.2",
@@ -123,7 +128,8 @@
     "eslint": "^9.27.0",
     "eslint-config-prettier": "^10.1.5",
     "eslint-doc-generator": "^2.1.2",
-    "eslint-import-resolver-typescript": "^4.4.0",
+    "eslint-import-resolver-node": "^0.3.9",
+    "eslint-import-resolver-typescript": "^4.4.1",
     "eslint-import-resolver-webpack": "^0.13.10",
     "eslint-import-test-order-redirect": "link:./test/fixtures/order-redirect",
     "eslint-plugin-eslint-plugin": "^6.4.0",

src/utils/arraify.ts

@@ -0,0 +1,2 @@
+export const arraify = <T>(value?: T | readonly T[]): T[] | undefined =>
+  value ? ((Array.isArray(value) ? value : [value]) as T[]) : undefined

src/utils/index.ts

@@ -10,6 +10,7 @@ export type {
   LegacyImportResolver,
 } from 'eslint-import-context'
 
+export * from './arraify.js'
 export * from './create-rule.js'
 export * from './declared-scope.js'
 export * from './docs-url.js'

src/utils/legacy-resolver-settings.ts

@@ -54,7 +54,6 @@ export function normalizeConfigResolvers(
   for (const nameOrRecordOrObject of resolverArray) {
     if (typeof nameOrRecordOrObject === 'string') {
       const name = nameOrRecordOrObject
-
       map.set(name, {
         name,
         enable: true,
@@ -64,26 +63,25 @@ export function normalizeConfigResolvers(
     } else if (typeof nameOrRecordOrObject === 'object') {
       if (nameOrRecordOrObject.name && nameOrRecordOrObject.resolver) {
         const object = nameOrRecordOrObject as LegacyResolverObject
-
         const { name, enable = true, options, resolver } = object
         map.set(name, { name, enable, options, resolver })
       } else {
         const record = nameOrRecordOrObject as LegacyResolverRecord
-
         for (const [name, enableOrOptions] of Object.entries(record)) {
+          const resolver = requireResolver(name, sourceFile)
           if (typeof enableOrOptions === 'boolean') {
             map.set(name, {
               name,
               enable: enableOrOptions,
               options: undefined,
-              resolver: requireResolver(name, sourceFile),
+              resolver,
             })
           } else {
             map.set(name, {
               name,
               enable: true,
               options: enableOrOptions,
-              resolver: requireResolver(name, sourceFile),
+              resolver,
             })
           }
         }
@@ -98,6 +96,18 @@ export function normalizeConfigResolvers(
   return [...map.values()]
 }
 
+export const LEGACY_NODE_RESOLVERS = [
+  'node',
+  'eslint-import-resolver-node',
+  (function () {
+    try {
+      return cjsRequire.resolve('eslint-import-resolver-node')
+    } catch {
+      // ignore
+    }
+  })(),
+].filter(Boolean)
+
 function requireResolver(name: string, sourceFile: string) {
   // Try to resolve package with conventional name
   const resolver =
@@ -106,10 +116,16 @@ function requireResolver(name: string, sourceFile: string) {
     tryRequire(path.resolve(getBaseDir(sourceFile), name))
 
   if (!resolver) {
+    // ignore `node` resolver not found error, we'll use the new one instead
+    if (LEGACY_NODE_RESOLVERS.includes(name)) {
+      return undefined!
+    }
+
     const err = new Error(`unable to load resolver "${name}".`)
     err.name = IMPORT_RESOLVE_ERROR_NAME
     throw err
   }
+
   if (!isLegacyResolverValid(resolver)) {
     const err = new Error(`${name} with invalid interface loaded as resolver`)
     err.name = IMPORT_RESOLVE_ERROR_NAME

src/utils/resolve.ts

@@ -5,17 +5,22 @@ import { fileURLToPath } from 'node:url'
 import { setRuleContext } from 'eslint-import-context'
 import { stableHash } from 'stable-hash'
 
+import { createNodeResolver } from '../node-resolver.js'
+import { cjsRequire } from '../require.js'
 import type {
   ChildContext,
   ImportSettings,
   LegacyResolver,
   NewResolver,
+  NodeResolverOptions,
   PluginSettings,
   RuleContext,
 } from '../types.js'
 
+import { arraify } from './arraify.js'
 import { makeContextCacheKey } from './export-map.js'
 import {
+  LEGACY_NODE_RESOLVERS,
   normalizeConfigResolvers,
   resolveWithLegacyResolver,
 } from './legacy-resolver-settings.js'
@@ -114,6 +119,98 @@ function isValidNewResolver(resolver: unknown): resolver is NewResolver {
   return true
 }
 
+function legacyNodeResolve(
+  resolverOptions: NodeResolverOptions,
+  context: ChildContext | RuleContext,
+  modulePath: string,
+  sourceFile: string,
+) {
+  const {
+    extensions,
+    includeCoreModules,
+    moduleDirectory,
+    paths,
+    preserveSymlinks: symlinks,
+    package: packageJson,
+    packageFilter,
+    pathFilter,
+    packageIterator,
+    ...rest
+  } = resolverOptions
+
+  const normalizedExtensions = arraify(extensions)
+
+  const modules = arraify(moduleDirectory)
+
+  const resolver = createNodeResolver({
+    extensions: normalizedExtensions,
+    builtinModules: includeCoreModules !== false,
+    modules,
+    symlinks,
+    ...rest,
+  })
+
+  const resolved = setRuleContext(context, () =>
+    resolver.resolve(modulePath, sourceFile),
+  )
+
+  if (resolved.found) {
+    return resolved
+  }
+
+  const normalizedPaths = arraify(paths)
+
+  if (normalizedPaths?.length) {
+    const paths = modules?.length
+      ? normalizedPaths.filter(p => !modules.includes(p))
+      : normalizedPaths
+
+    if (paths.length > 0) {
+      const resolver = createNodeResolver({
+        extensions: normalizedExtensions,
+        builtinModules: includeCoreModules !== false,
+        modules: paths,
+        symlinks,
+        ...rest,
+      })
+
+      const resolved = setRuleContext(context, () =>
+        resolver.resolve(modulePath, sourceFile),
+      )
+
+      if (resolved.found) {
+        return resolved
+      }
+    }
+  }
+
+  if (
+    [packageJson, packageFilter, pathFilter, packageIterator].some(
+      it => it != null,
+    )
+  ) {
+    let legacyNodeResolver: LegacyResolver
+    try {
+      legacyNodeResolver = cjsRequire<LegacyResolver>(
+        'eslint-import-resolver-node',
+      )
+    } catch {
+      throw new Error(
+        "You're using legacy resolver options which are not supported by the new resolver and `eslint-import-resolver-node` is not installed as fallback,\nplease install `eslint-import-resolver-node` manually or remove those legacy resolver options including `package`, `packageFilter`, `pathFilter` and `packageIterator`.",
+      )
+    }
+    const resolved = resolveWithLegacyResolver(
+      legacyNodeResolver,
+      resolverOptions,
+      modulePath,
+      sourceFile,
+    )
+    if (resolved.found) {
+      return resolved
+    }
+  }
+}
+
 function fullResolve(
   modulePath: string,
   sourceFile: string,
@@ -140,11 +237,11 @@ function fullResolve(
 
   const cacheKey =
     sourceDir +
-    ',' +
+    '\0' +
     childContextHashKey +
-    ',' +
+    '\0' +
     memoizedHash +
-    ',' +
+    '\0' +
     modulePath
 
   const cacheSettings = ModuleCache.getSettings(settings)
@@ -154,10 +251,7 @@ function fullResolve(
     return { found: true, path: cachedPath }
   }
 
-  if (
-    Object.hasOwn(settings, 'import-x/resolver-next') &&
-    settings['import-x/resolver-next']
-  ) {
+  if (settings['import-x/resolver-next']) {
     let configResolvers = settings['import-x/resolver-next']
 
     if (!Array.isArray(configResolvers)) {
@@ -196,14 +290,36 @@ function fullResolve(
         node: settings['import-x/resolve'],
       } // backward compatibility
 
-    for (const { enable, options, resolver } of normalizeConfigResolvers(
+    for (const { enable, name, options, resolver } of normalizeConfigResolvers(
       configResolvers,
       sourceFile,
     )) {
       if (!enable) {
         continue
       }
 
+      // if the resolver is `eslint-import-resolver-node`, we use the new `node` resolver as fallback instead
+      if (LEGACY_NODE_RESOLVERS.includes(name) && !resolver) {
+        const resolverOptions = (options || {}) as NodeResolverOptions
+        const resolved = legacyNodeResolve(
+          {
+            ...resolverOptions,
+            extensions:
+              resolverOptions.extensions || settings['import-x/extensions'],
+          },
+          context,
+          modulePath,
+          sourceFile,
+        )
+
+        if (resolved?.found) {
+          fileExistsCache.set(cacheKey, resolved.path)
+          return resolved
+        }
+
+        continue
+      }
+
       const resolved = setRuleContext(context, () =>
         resolveWithLegacyResolver(resolver, options, modulePath, sourceFile),
       )