Reogranize the client component detection utils

packages/next/build/webpack/loaders/next-flight-client-loader.ts

@@ -8,9 +8,7 @@
 import { promisify } from 'util'
 
 import { parse } from '../../swc'
-import { buildExports } from './utils'
-
-const IS_NEXT_CLIENT_BUILT_IN = /[\\/]next[\\/](link|image)\.js$/
+import { buildExports, isNextBuiltinClientComponent } from './utils'
 
 function addExportNames(names: string[], node: any) {
   if (!node) return
@@ -59,7 +57,7 @@ async function collectExports(
   const names: string[] = []
 
   // Next.js built-in client components
-  if (IS_NEXT_CLIENT_BUILT_IN.test(resourcePath)) {
+  if (isNextBuiltinClientComponent(resourcePath)) {
     names.push('default')
   }
 
@@ -160,7 +158,7 @@ export default async function transformSource(
   const moduleRefDef =
     "const MODULE_REFERENCE = Symbol.for('react.module.reference');\n"
 
-  const isNextClientBuiltIn = IS_NEXT_CLIENT_BUILT_IN.test(resourcePath)
+  const isNextClientBuiltIn = isNextBuiltinClientComponent(resourcePath)
 
   const clientRefsExports = names.reduce((res: any, name) => {
     const moduleRef =

packages/next/build/webpack/loaders/next-flight-server-loader.ts

@@ -1,30 +1,11 @@
 import { builtinModules } from 'module'
 
 import { parse } from '../../swc'
-import { buildExports } from './utils'
-
-const imageExtensions = ['jpg', 'jpeg', 'png', 'webp', 'avif']
-
-export const createClientComponentFilter = (extensions: string[]) => {
-  // Special cases for Next.js APIs that are considered as client components:
-  // - .client.[ext]
-  // - next built-in client components
-  // - .[imageExt]
-  const regex = new RegExp(
-    '(' +
-      `\\.client(\\.(${extensions.join('|')}))?|` +
-      `next/(link|image)(\\.js)?|` +
-      `\\.(${imageExtensions.join('|')})` +
-      ')$'
-  )
-
-  return (importSource: string) => regex.test(importSource)
-}
-
-export const createServerComponentFilter = (extensions: string[]) => {
-  const regex = new RegExp(`\\.server(\\.(${extensions.join('|')}))?$`)
-  return (importSource: string) => regex.test(importSource)
-}
+import {
+  buildExports,
+  createClientComponentFilter,
+  createServerComponentFilter,
+} from './utils'
 
 function createFlightServerRequest(request: string, options: object) {
   return `next-flight-server-loader?${JSON.stringify(options)}!${request}`

packages/next/build/webpack/loaders/utils.ts

@@ -1,3 +1,15 @@
+const defaultJsFileExtensions = ['js', 'mjs', 'jsx', 'ts', 'tsx', 'json']
+const imageExtensions = ['jpg', 'jpeg', 'png', 'webp', 'avif']
+const nextClientComponents = ['link', 'image', 'script']
+
+const NEXT_BUILT_IN_CLIENT_RSC_REGEX = new RegExp(
+  `[\\\\/]next[\\\\/](${nextClientComponents.join('|')})\\.js$`
+)
+
+export function isNextBuiltinClientComponent(resourcePath: string) {
+  return NEXT_BUILT_IN_CLIENT_RSC_REGEX.test(resourcePath)
+}
+
 export function buildExports(moduleExports: any, isESM: boolean) {
   let ret = ''
   Object.keys(moduleExports).forEach((key) => {
@@ -11,3 +23,26 @@ export function buildExports(moduleExports: any, isESM: boolean) {
   })
   return ret
 }
+
+export const createClientComponentFilter = (
+  extensions: string[] = defaultJsFileExtensions
+) => {
+  // Special cases for Next.js APIs that are considered as client components:
+  // - .client.[ext]
+  // - next built-in client components
+  // - .[imageExt]
+  const regex = new RegExp(
+    '(' +
+      `\\.client(\\.(${extensions.join('|')}))?|` +
+      `next/(${nextClientComponents.join('|')})(\\.js)?|` +
+      `\\.(${imageExtensions.join('|')})` +
+      ')$'
+  )
+
+  return (importSource: string) => regex.test(importSource)
+}
+
+export const createServerComponentFilter = (extensions: string[]) => {
+  const regex = new RegExp(`\\.server(\\.(${extensions.join('|')}))?$`)
+  return (importSource: string) => regex.test(importSource)
+}

packages/next/build/webpack/plugins/flight-manifest-plugin.ts

@@ -7,7 +7,7 @@
 
 import { webpack, sources } from 'next/dist/compiled/webpack/webpack'
 import { MIDDLEWARE_FLIGHT_MANIFEST } from '../../../shared/lib/constants'
-import { createClientComponentFilter } from '../loaders/next-flight-server-loader'
+import { createClientComponentFilter } from '../loaders/utils'
 
 // This is the module that will be used to anchor all client references to.
 // I.e. it will have all the client files as async deps from this point on.

test/integration/react-streaming-and-server-components/app/pages/index.server.js

@@ -1,4 +1,5 @@
 import Nav from '../components/nav'
+import Script from 'next/script'
 
 const envVar = process.env.ENV_VAR_TEST
 const headerKey = 'x-next-test-client'
@@ -10,6 +11,7 @@ export default function Index({ header }) {
       <div>{'env:' + envVar}</div>
       <div>{'header:' + header}</div>
       <Nav />
+      <Script id="client-script">{`;`}</Script>
     </div>
   )
 }

test/integration/react-streaming-and-server-components/test/rsc.js

@@ -14,11 +14,14 @@ export default function (context, { runtime, env }) {
       },
     })
 
+    const browser = await webdriver(context.appPort, '/')
+    const scriptTagContent = await browser.elementById('client-script').text()
     // should have only 1 DOCTYPE
     expect(homeHTML).toMatch(/^<!DOCTYPE html><html/)
     expect(homeHTML).toContain('component:index.server')
     expect(homeHTML).toContain('env:env_var_test')
     expect(homeHTML).toContain('header:test-util')
+    expect(scriptTagContent).toBe(';')
   })
 
   it('should reuse the inline flight response without sending extra requests', async () => {