feat!: use enhanced-resolve instead

package.json

@@ -63,19 +63,21 @@
   },
   "dependencies": {
     "debug": "^4.3.4",
+    "enhanced-resolve": "^5.9.3",
     "get-tsconfig": "^4.0.6",
     "globby": "^13.1.2",
+    "is-core-module": "^2.9.0",
     "is-glob": "^4.0.3",
-    "resolve": "^1.22.1",
     "synckit": "^0.7.1"
   },
   "devDependencies": {
-    "@1stg/lib-config": "^6.2.3",
+    "@1stg/lib-config": "^6.3.0",
+    "@mozilla/glean": "^1.0.0",
     "@types/debug": "^4.1.7",
-    "@types/glob": "^7.2.0",
+    "@types/enhanced-resolve": "^3.0.7",
+    "@types/is-core-module": "^2.2.0",
     "@types/is-glob": "^4.0.2",
     "@types/node": "^18.0.0",
-    "@types/resolve": "^1.20.2",
     "@types/unist": "^2.0.6",
     "dummy.js": "link:dummy.js",
     "eslint-import-resolver-typescript": "link:.",

src/index.ts

@@ -3,9 +3,15 @@ import path from 'node:path'
 import { fileURLToPath } from 'node:url'
 
 import debug from 'debug'
+import {
+  FileSystem,
+  ResolveOptions,
+  Resolver,
+  ResolverFactory,
+} from 'enhanced-resolve'
 import { createPathsMatcher, getTsconfig } from 'get-tsconfig'
+import isCore from 'is-core-module'
 import isGlob from 'is-glob'
-import { isCore, type PackageJSON, sync, SyncOpts } from 'resolve'
 import { createSyncFn } from 'synckit'
 
 const IMPORTER_NAME = 'eslint-import-resolver-typescript'
@@ -21,15 +27,50 @@ const globSync = createSyncFn<typeof import('globby').globby>(
   path.resolve(_dirname, 'worker.mjs'),
 )
 
+/**
+ * .mts, .cts, .d.mts, .d.cts, .mjs, .cjs are not included because .cjs and .mjs must be used explicitly.
+ */
+const defaultExtensions = [
+  '.ts',
+  '.tsx',
+  '.d.ts',
+  '.js',
+  '.jsx',
+  '.json',
+  '.node',
+]
+
+const defaultMainFields = [
+  'types',
+  'typings',
+  'module',
+  'jsnext:main',
+
+  // https://angular.io/guide/angular-package-format
+  'esm2020',
+  'es2020',
+  'fesm2020',
+  'fesm2015',
+
+  'main',
+]
+
 export const interfaceVersion = 2
 
-export type TsResolverOptions = SyncOpts & {
+export interface TsResolverOptions
+  extends Omit<ResolveOptions, 'fileSystem' | 'useSyncFileSystemCalls'> {
   alwaysTryTypes?: boolean
   project?: string[] | string
   extensions?: string[]
   packageFilter?: (pkg: Record<string, string>) => Record<string, string>
 }
 
+const fileSystem = fs as FileSystem
+
+let mappersBuildForOptions: TsResolverOptions
+let mappers: Array<((specifier: string) => string[]) | null> | undefined
+let resolver: Resolver
+
 /**
  * @param {string} source the module to resolve; i.e './some-module'
  * @param {string} file the importing file's full path; i.e. '/usr/local/bin/file.js'
@@ -38,12 +79,20 @@ export type TsResolverOptions = SyncOpts & {
 export function resolve(
   source: string,
   file: string,
-  options: TsResolverOptions | null,
+  options?: TsResolverOptions | null,
 ): {
   found: boolean
   path?: string | null
 } {
-  options = options ?? {}
+  const opts: ResolveOptions & TsResolverOptions = {
+    ...options,
+    extensions: options?.extensions ?? defaultExtensions,
+    mainFields: options?.mainFields ?? defaultMainFields,
+    fileSystem,
+    useSyncFileSystemCalls: true,
+  }
+
+  resolver = ResolverFactory.createResolver(opts)
 
   log('looking for:', source)
 
@@ -59,7 +108,7 @@ export function resolve(
     }
   }
 
-  initMappers(options)
+  initMappers(opts)
 
   const mappedPath = getMappedPath(source, file, true)
   if (mappedPath) {
@@ -69,11 +118,9 @@ export function resolve(
   // note that even if we map the path, we still need to do a final resolve
   let foundNodePath: string | null | undefined
   try {
-    foundNodePath = tsResolve(mappedPath ?? source, {
-      ...options,
-      basedir: path.dirname(path.resolve(file)),
-      packageFilter: options.packageFilter ?? packageFilterDefault,
-    })
+    foundNodePath =
+      tsResolve(mappedPath ?? source, path.dirname(path.resolve(file)), opts) ||
+      null
   } catch {
     foundNodePath = null
   }
@@ -82,7 +129,7 @@ export function resolve(
   // if path is neither absolute nor relative
   if (
     (/\.jsx?$/.test(foundNodePath!) ||
-      (options.alwaysTryTypes && !foundNodePath)) &&
+      (opts.alwaysTryTypes && !foundNodePath)) &&
     !/^@types[/\\]/.test(source) &&
     !path.isAbsolute(source) &&
     !source.startsWith('.')
@@ -113,12 +160,6 @@ export function resolve(
   }
 }
 
-function packageFilterDefault(pkg: PackageJSON) {
-  pkg.main =
-    pkg.types || pkg.typings || pkg.module || pkg['jsnext:main'] || pkg.main
-  return pkg
-}
-
 function resolveExtension(id: string) {
   const idWithoutJsExt = removeJsExtension(id)
 
@@ -149,16 +190,21 @@ function resolveExtension(id: string) {
  * Like `sync` from `resolve` package, but considers that the module id
  * could have a .js or .jsx extension.
  */
-function tsResolve(id: string, opts: SyncOpts): string {
+function tsResolve(
+  source: string,
+  base: string,
+  options: ResolveOptions,
+): string | false {
   try {
-    return sync(id, opts)
+    return resolver.resolveSync({}, base, source)
   } catch (error) {
-    const resolved = resolveExtension(id)
+    const resolved = resolveExtension(source)
     if (resolved) {
-      return sync(resolved.path, {
-        ...opts,
-        extensions: resolved.extensions ?? opts.extensions,
+      const resolver = ResolverFactory.createResolver({
+        ...options,
+        extensions: resolved.extensions ?? options.extensions,
       })
+      return resolver.resolveSync({}, base, resolved.path)
     }
     throw error
   }
@@ -178,9 +224,6 @@ function removeJsExtension(id: string) {
   return id.replace(/\.([cm]js|jsx?)$/, '')
 }
 
-let mappersBuildForOptions: TsResolverOptions
-let mappers: Array<((specifier: string) => string[]) | null> | undefined
-
 const JS_EXT_PATTERN = /\.([cm]js|jsx?)$/
 const RELATIVE_PATH_PATTERN = /^\.{1,2}(\/.*)?$/
 

tests/withJsExtension/test.js

@@ -127,4 +127,5 @@ assertResolve(
   '../../node_modules/typescript/lib/typescript.js',
 )
 
-assertResolve('dummy.js', '../../node_modules/dummy.js/index.js')
+// resolves symlinks by default
+assertResolve('dummy.js', '../../dummy.js/index.js')

tests/withoutPaths/index.ts

@@ -15,3 +15,6 @@ import 'json5'
 
 // enable alwaysTryTypes
 import 'unist'
+
+// exports
+import '@mozilla/glean/webext'