perf: don't resolve import path, if it was already resolved

packages/vite-node/src/client.ts

@@ -278,7 +278,6 @@ export class ViteNodeRunner {
     if (id in requestStubs)
       return requestStubs[id]
 
-    // eslint-disable-next-line prefer-const
     let { code: transformed, externalize } = await this.options.fetchModule(id)
 
     if (externalize) {

packages/vite-node/src/server.ts

@@ -1,10 +1,10 @@
 import { performance } from 'node:perf_hooks'
-import { resolve } from 'pathe'
+import { isAbsolute, join, resolve } from 'pathe'
 import type { TransformResult, ViteDevServer } from 'vite'
 import createDebug from 'debug'
 import type { DebuggerOptions, FetchResult, RawSourceMap, ViteNodeResolveId, ViteNodeServerOptions } from './types'
 import { shouldExternalize } from './externalize'
-import { normalizeModuleId, toArray, toFilePath } from './utils'
+import { isWindows, normalizeModuleId, slash, toArray, toFilePath } from './utils'
 import { Debugger } from './debug'
 import { withInlineSourcemap } from './source-map'
 
@@ -65,6 +65,18 @@ export class ViteNodeServer {
   }
 
   async resolveId(id: string, importer?: string): Promise<ViteNodeResolveId | null> {
+    if (id.startsWith('/@fs/')) {
+      const fsPath = slash(id.slice(4))
+      return { id: isWindows ? fsPath.slice(1) : fsPath }
+    }
+    if (isAbsolute(id)) {
+      const moduleMap = this.server.moduleGraph.idToModuleMap
+      if (moduleMap.has(id))
+        return { id }
+      const fsPath = join(this.server.config.root, id)
+      if (moduleMap.has(fsPath))
+        return { id: fsPath }
+    }
     if (importer && !importer.startsWith(this.server.config.root))
       importer = resolve(this.server.config.root, importer)
     const mode = (importer && this.getTransformMode(importer)) || 'ssr'

test/core/test/imports.test.ts

@@ -28,7 +28,7 @@ test('dynamic aliased import works', async () => {
   expect(stringTimeoutMod).toBe(variableTimeoutMod)
 })
 
-test('dynamic absolute import works', async () => {
+test('dynamic absolute from root import works', async () => {
   const stringTimeoutMod = await import('./../src/timeout')
 
   const timeoutPath = '/src/timeout'
@@ -37,6 +37,15 @@ test('dynamic absolute import works', async () => {
   expect(stringTimeoutMod).toBe(variableTimeoutMod)
 })
 
+test('dynamic absolute with extension mport works', async () => {
+  const stringTimeoutMod = await import('./../src/timeout')
+
+  const timeoutPath = '/src/timeout.ts'
+  const variableTimeoutMod = await import(timeoutPath)
+
+  expect(stringTimeoutMod).toBe(variableTimeoutMod)
+})
+
 test('data with dynamic import works', async () => {
   const dataUri = 'data:text/javascript;charset=utf-8,export default "hi"'
   const { default: hi } = await import(dataUri)

test/vite-node/test/server.test.ts

@@ -10,6 +10,9 @@ describe('server works correctly', async () => {
       config: {
         root: '/',
       },
+      moduleGraph: {
+        idToModuleMap: new Map(),
+      },
     } as any, {
       transformMode: {
         web: [/web/],