Remove the special _document-concurrent component (#35242)

This PR removes the `` const documentPage = `_document${globalRuntime ? '-concurrent' : ''}` `` condition from the config resolution phrase, and only use the built-in one. And later when rendering, we can conditionally convert the default class component into a function component. This change is necessary for the switchable runtime feature (#31506). ## Bug - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Errors have helpful link attached, see `contributing.md` ## Feature - [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR. - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Documentation added - [ ] Telemetry added. In case of a feature if it's used or not. - [ ] Errors have helpful link attached, see `contributing.md` ## Documentation / Examples - [ ] Make sure the linting passes by running `yarn lint`
vercel · Mar 11, 2022 · 3b9864d · 3b9864d
1 parent bc0816f
commit 3b9864d
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Showing 10 changed files with 50 additions and 44 deletions.
diff --git a/packages/next/build/entries.ts b/packages/next/build/entries.ts
@@ -39,11 +39,9 @@ export function createPagesMapping(
   {
     isDev,
     hasServerComponents,
-    globalRuntime,
   }: {
     isDev: boolean
     hasServerComponents: boolean
-    globalRuntime?: 'nodejs' | 'edge'
   }
 ): PagesMapping {
   const previousPages: PagesMapping = {}
@@ -83,16 +81,14 @@ export function createPagesMapping(
   // we alias these in development and allow webpack to
   // allow falling back to the correct source file so
   // that HMR can work properly when a file is added/removed
-  const documentPage = `_document${globalRuntime ? '-concurrent' : ''}`
   if (isDev) {
     pages['/_app'] = `${PAGES_DIR_ALIAS}/_app`
     pages['/_error'] = `${PAGES_DIR_ALIAS}/_error`
     pages['/_document'] = `${PAGES_DIR_ALIAS}/_document`
   } else {
     pages['/_app'] = pages['/_app'] || 'next/dist/pages/_app'
     pages['/_error'] = pages['/_error'] || 'next/dist/pages/_error'
-    pages['/_document'] =
-      pages['/_document'] || `next/dist/pages/${documentPage}`
+    pages['/_document'] = pages['/_document'] || `next/dist/pages/_document`
   }
   return pages
 }

diff --git a/packages/next/build/index.ts b/packages/next/build/index.ts
@@ -298,7 +298,6 @@ export default async function build(
         createPagesMapping(pagePaths, config.pageExtensions, {
           isDev: false,
           hasServerComponents,
-          globalRuntime: runtime,
         })
       )
 

diff --git a/packages/next/build/webpack-config.ts b/packages/next/build/webpack-config.ts
@@ -558,9 +558,7 @@ export default async function getBaseWebpackConfig(
         prev.push(path.join(pagesDir, `_document.${ext}`))
         return prev
       }, [] as string[]),
-      `next/dist/pages/_document${
-        hasConcurrentFeatures ? '-concurrent' : ''
-      }.js`,
+      `next/dist/pages/_document.js`,
     ]
   }
 

diff --git a/packages/next/pages/_document-concurrent.tsx b/packages/next/pages/_document-concurrent.tsx
diff --git a/packages/next/pages/_document.tsx b/packages/next/pages/_document.tsx
@@ -184,6 +184,21 @@ export default class Document<P = {}> extends Component<DocumentProps & P> {
   }
 }
 
+// Add a speical property to the built-in `Document` component so later we can
+// identify if a user customized `Document` is used or not.
+;(Document as any).__next_internal_document =
+  function InternalFunctionDocument() {
+    return (
+      <Html>
+        <Head />
+        <body>
+          <Main />
+          <NextScript />
+        </body>
+      </Html>
+    )
+  }
+
 export function Html(
   props: React.DetailedHTMLProps<
     React.HtmlHTMLAttributes<HTMLHtmlElement>,

diff --git a/packages/next/server/base-server.ts b/packages/next/server/base-server.ts
@@ -1176,14 +1176,21 @@ export default abstract class Server {
 
     if (opts.supportsDynamicHTML === true) {
       const isBotRequest = isBot(req.headers['user-agent'] || '')
+      const isSupportedDocument =
+        typeof components.Document?.getInitialProps !== 'function' ||
+        // When concurrent features is enabled, the built-in `Document`
+        // component also supports dynamic HTML.
+        (this.renderOpts.reactRoot &&
+          !!(components.Document as any)?.__next_internal_document)
+
       // Disable dynamic HTML in cases that we know it won't be generated,
       // so that we can continue generating a cache key when possible.
       opts.supportsDynamicHTML =
         !isSSG &&
         !isLikeServerless &&
         !isBotRequest &&
         !query.amp &&
-        typeof components.Document?.getInitialProps !== 'function'
+        isSupportedDocument
     }
 
     const defaultLocale = isSSG

diff --git a/packages/next/server/dev/hot-reloader.ts b/packages/next/server/dev/hot-reloader.ts
@@ -321,7 +321,6 @@ export default class HotReloader {
             this.config.pageExtensions,
             {
               isDev: true,
-              globalRuntime: this.runtime,
               hasServerComponents: this.hasServerComponents,
             }
           )

diff --git a/packages/next/server/dev/next-dev-server.ts b/packages/next/server/dev/next-dev-server.ts
@@ -949,9 +949,7 @@ export default class DevServer extends Server {
     // Build the error page to ensure the fallback is built too.
     // TODO: See if this can be moved into hotReloader or removed.
     await this.hotReloader!.ensurePage('/_error')
-    return await loadDefaultErrorComponents(this.distDir, {
-      hasConcurrentFeatures: !!this.renderOpts.runtime,
-    })
+    return await loadDefaultErrorComponents(this.distDir)
   }
 
   protected setImmutableAssetCacheControl(res: BaseNextResponse): void {

diff --git a/packages/next/server/load-components.ts b/packages/next/server/load-components.ts
@@ -39,14 +39,8 @@ export type LoadComponentsReturnType = {
   AppMod: any
 }
 
-export async function loadDefaultErrorComponents(
-  distDir: string,
-  { hasConcurrentFeatures }: { hasConcurrentFeatures: boolean }
-) {
-  const Document = interopDefault(
-    require(`next/dist/pages/_document` +
-      (hasConcurrentFeatures ? '-concurrent' : ''))
-  )
+export async function loadDefaultErrorComponents(distDir: string) {
+  const Document = interopDefault(require('next/dist/pages/_document'))
   const AppMod = require('next/dist/pages/_app')
   const App = interopDefault(AppMod)
   const ComponentMod = require('next/dist/pages/_error')

diff --git a/packages/next/server/render.tsx b/packages/next/server/render.tsx
@@ -431,7 +431,6 @@ export async function renderToHTML(
     dev = false,
     ampPath = '',
     App,
-    Document,
     pageConfig = {},
     buildManifest,
     fontManifest,
@@ -457,6 +456,7 @@ export async function renderToHTML(
 
   const hasConcurrentFeatures = !!runtime
 
+  let Document = renderOpts.Document
   const OriginalComponent = renderOpts.Component
 
   // We don't need to opt-into the flight inlining logic if the page isn't a RSC.
@@ -1234,14 +1234,30 @@ export async function renderToHTML(
    */
   const generateStaticHTML = supportsDynamicHTML !== true
   const renderDocument = async () => {
+    // For `Document`, there are two cases that we don't support:
+    // 1. Using `Document.getInitialProps` in the Edge runtime.
+    // 2. Using the class component `Document` with concurrent features.
+
+    const builtinDocument = (Document as any).__next_internal_document as
+      | typeof Document
+      | undefined
+
     if (runtime === 'edge' && Document.getInitialProps) {
-      // In the Edge runtime, Document.getInitialProps isn't supported.
-      throw new Error(
-        '`getInitialProps` in Document component is not supported with the Edge Runtime.'
-      )
+      // In the Edge runtime, `Document.getInitialProps` isn't supported.
+      // We throw an error here if it's customized.
+      if (!builtinDocument) {
+        throw new Error(
+          '`getInitialProps` in Document component is not supported with the Edge Runtime.'
+        )
+      }
+    }
+
+    // We make it a function component to enable streaming.
+    if (hasConcurrentFeatures && builtinDocument) {
+      Document = builtinDocument
     }
 
-    if (!runtime && Document.getInitialProps) {
+    if (!hasConcurrentFeatures && Document.getInitialProps) {
       const renderPage: RenderPage = (
         options: ComponentsEnhancer = {}
       ): RenderPageResult | Promise<RenderPageResult> => {