Support require.extensions mutations (tailwindlabs#583)

Author: bradlc

packages/tailwindcss-language-server/src/util/resolveFrom.ts

@@ -1,24 +1,38 @@
 import * as fs from 'fs'
 import { CachedInputFileSystem, ResolverFactory, Resolver, ResolveOptions } from 'enhanced-resolve'
+import { equal } from 'tailwindcss-language-service/src/util/array'
+
+let pnpApi: any
+let extensions = Object.keys(require.extensions)
 
 function createResolver(options: Partial<ResolveOptions> = {}): Resolver {
   return ResolverFactory.createResolver({
     fileSystem: new CachedInputFileSystem(fs, 4000),
     useSyncFileSystemCalls: true,
     // cachePredicate: () => false,
     conditionNames: ['node', 'require'],
+    extensions,
+    pnpApi,
     ...options,
   })
 }
 
 let resolver = createResolver()
 
-export function setPnpApi(pnpApi: any): void {
-  resolver = createResolver({ pnpApi })
+export function setPnpApi(newPnpApi: any): void {
+  pnpApi = newPnpApi
+  resolver = createResolver()
 }
 
 export default function resolveFrom(from?: string, id?: string): string {
   if (id.startsWith('\\\\')) return id
+
+  let newExtensions = Object.keys(require.extensions)
+  if (!equal(newExtensions, extensions)) {
+    extensions = newExtensions
+    resolver = createResolver()
+  }
+
   let result = resolver.resolveSync({}, from, id)
   if (result === false) throw Error()
   // https://github.com/webpack/enhanced-resolve/issues/282