From 482fe25cbbf6e0a0c72003c61e36087673dd18b6 Mon Sep 17 00:00:00 2001
From: JJ Kasper <jj@jjsweb.site>
Date: Tue, 10 May 2022 11:57:14 -0500
Subject: [PATCH] Update root component handling (#36781)

---
 .../build/webpack/loaders/next-view-loader.ts | 28 +++++--
 packages/next/server/view-render.tsx          | 80 ++++++++++---------
 .../dashboard/another/page.server.js          |  7 ++
 .../app/views/(newroot)/layout.server.js      | 19 +++++
 .../deployments/breakdown/page.server.js      |  7 ++
 .../views/dashboard/(custom)/layout.server.js |  8 ++
 test/e2e/views-dir/app/views/layout.server.js | 12 ++-
 test/e2e/views-dir/index.test.ts              | 55 +++++++++++--
 8 files changed, 166 insertions(+), 50 deletions(-)
 create mode 100644 test/e2e/views-dir/app/views/(newroot)/dashboard/another/page.server.js
 create mode 100644 test/e2e/views-dir/app/views/(newroot)/layout.server.js
 create mode 100644 test/e2e/views-dir/app/views/dashboard/(custom)/deployments/breakdown/page.server.js
 create mode 100644 test/e2e/views-dir/app/views/dashboard/(custom)/layout.server.js

diff --git a/packages/next/build/webpack/loaders/next-view-loader.ts b/packages/next/build/webpack/loaders/next-view-loader.ts
index 1f4ca331584f..4374b9ff3673 100644
--- a/packages/next/build/webpack/loaders/next-view-loader.ts
+++ b/packages/next/build/webpack/loaders/next-view-loader.ts
@@ -22,18 +22,34 @@ async function resolveLayoutPathsByPage({
 }) {
   const layoutPaths = new Map<string, string | undefined>()
   const parts = pagePath.split('/')
+  const isNewRootLayout =
+    parts[1]?.length > 2 && parts[1]?.startsWith('(') && parts[1]?.endsWith(')')
 
-  for (let i = 1; i < parts.length; i++) {
+  for (let i = parts.length; i >= 0; i--) {
     const pathWithoutSlashLayout = parts.slice(0, i).join('/')
-    const layoutPath = `${pathWithoutSlashLayout}/layout`
-
-    const resolvedLayoutPath = await resolve(layoutPath)
 
+    if (!pathWithoutSlashLayout) {
+      continue
+    }
+    const layoutPath = `${pathWithoutSlashLayout}/layout`
+    let resolvedLayoutPath = await resolve(layoutPath)
     let urlPath = pathToUrlPath(pathWithoutSlashLayout)
 
+    // if we are in a new root views/(root) and a custom root layout was
+    // not provided or a root layout views/layout is not present, we use
+    // a default root layout to provide the html/body tags
+    const isCustomRootLayout = isNewRootLayout && i === 2
+
+    if ((isCustomRootLayout || i === 1) && !resolvedLayoutPath) {
+      resolvedLayoutPath = await resolve('next/dist/lib/views-layout')
+    }
     layoutPaths.set(urlPath, resolvedLayoutPath)
-  }
 
+    // if we're in a new root layout don't add the top-level view/layout
+    if (isCustomRootLayout) {
+      break
+    }
+  }
   return layoutPaths
 }
 
@@ -84,7 +100,7 @@ const nextViewLoader: webpack.LoaderDefinitionFunction<{
   // Add page itself to the list of components
   componentsCode.push(
     `'${pathToUrlPath(pagePath).replace(
-      new RegExp(`/page\\.+(${extensions.join('|')})$`),
+      new RegExp(`/page+(${extensions.join('|')})$`),
       ''
       // use require so that we can bust the require cache
     )}': () => require('${pagePath}')`
diff --git a/packages/next/server/view-render.tsx b/packages/next/server/view-render.tsx
index f304f2472ce6..8952c5f493aa 100644
--- a/packages/next/server/view-render.tsx
+++ b/packages/next/server/view-render.tsx
@@ -19,7 +19,6 @@ import {
 import { FlushEffectsContext } from '../shared/lib/flush-effects'
 import { isDynamicRoute } from '../shared/lib/router/utils'
 import { tryGetPreviewData } from './api-utils/node'
-import DefaultRootLayout from '../lib/views-layout'
 
 const ReactDOMServer = process.env.__NEXT_REACT_ROOT
   ? require('react-dom/server.browser')
@@ -218,10 +217,13 @@ export async function renderToHTML(
 
   const isFlight = query.__flight__ !== undefined
   const flightRouterPath = isFlight ? query.__flight_router_path__ : undefined
+  delete query.__flight__
+  delete query.__flight_router_path__
 
   const hasConcurrentFeatures = !!runtime
   const pageIsDynamic = isDynamicRoute(pathname)
-  const components = Object.keys(ComponentMod.components)
+  const componentPaths = Object.keys(ComponentMod.components)
+  const components = componentPaths
     .filter((path) => {
       // Rendering part of the page is only allowed for flight data
       if (flightRouterPath) {
@@ -238,6 +240,8 @@ export async function renderToHTML(
       return mod
     })
 
+  const isSubtreeRender = components.length < componentPaths.length
+
   // Reads of this are cached on the `req` object, so this should resolve
   // instantly. There's no need to pass this data down from a previous
   // invoke, where we'd have to consider server & serverless.
@@ -247,22 +251,12 @@ export async function renderToHTML(
     (renderOpts as any).previewProps
   )
   const isPreview = previewData !== false
-
-  let WrappedComponent: any
-  let RootLayout: any
-
   const dataCache = new Map<string, Record>()
+  let WrappedComponent: any
 
   for (let i = components.length - 1; i >= 0; i--) {
     const dataCacheKey = i.toString()
     const layout = components[i]
-
-    if (i === 0) {
-      // top-most layout is the root layout that renders
-      // the html/body tags
-      RootLayout = layout.Component
-      continue
-    }
     let fetcher: any
 
     // TODO: pass a shared cache from previous getStaticProps/
@@ -313,8 +307,7 @@ export async function renderToHTML(
 
     // eslint-disable-next-line no-loop-func
     const lastComponent = WrappedComponent
-    WrappedComponent = () => {
-      let props: any
+    WrappedComponent = (props: any) => {
       if (fetcher) {
         // The data fetching was kicked off before rendering (see above)
         // if the data was not resolved yet the layout rendering will be suspended
@@ -325,7 +318,25 @@ export async function renderToHTML(
         )
         // Result of calling getStaticProps or getServerSideProps. If promise is not resolve yet it will suspend.
         const recordValue = readRecordValue(record)
-        props = recordValue.props
+
+        if (props) {
+          props = Object.assign({}, props, recordValue.props)
+        } else {
+          props = recordValue.props
+        }
+      }
+
+      // if this is the root layout pass children as bodyChildren prop
+      if (!isSubtreeRender && i === 0) {
+        return React.createElement(layout.Component, {
+          ...props,
+          headChildren: props.headChildren,
+          bodyChildren: React.createElement(
+            lastComponent || React.Fragment,
+            {},
+            null
+          ),
+        })
       }
 
       return React.createElement(
@@ -345,14 +356,11 @@ export async function renderToHTML(
     // }
   }
 
-  // Fall back to default root layout that renders <html> / <head> / <body>
-  if (!RootLayout) {
-    RootLayout = DefaultRootLayout
-  }
-
-  const headChildren = buildManifest.rootMainFiles.map((src) => (
-    <script src={'/_next/' + src} async key={src} />
-  ))
+  const headChildren = !isSubtreeRender
+    ? buildManifest.rootMainFiles.map((src) => (
+        <script src={'/_next/' + src} async key={src} />
+      ))
+    : undefined
 
   let serverComponentsInlinedTransformStream: TransformStream<
     Uint8Array,
@@ -362,11 +370,15 @@ export async function renderToHTML(
   serverComponentsInlinedTransformStream = new TransformStream()
   const search = stringifyQuery(query)
 
-  const Component = createServerComponentRenderer(RootLayout, ComponentMod, {
-    cachePrefix: pathname + (search ? `?${search}` : ''),
-    transformStream: serverComponentsInlinedTransformStream,
-    serverComponentManifest,
-  })
+  const Component = createServerComponentRenderer(
+    WrappedComponent,
+    ComponentMod,
+    {
+      cachePrefix: pathname + (search ? `?${search}` : ''),
+      transformStream: serverComponentsInlinedTransformStream,
+      serverComponentManifest,
+    }
+  )
 
   // const serverComponentProps = query.__props__
   //   ? JSON.parse(query.__props__ as string)
@@ -417,10 +429,7 @@ export async function renderToHTML(
   if (renderServerComponentData) {
     return new RenderResult(
       renderToReadableStream(
-        <RootLayout
-          headChildren={headChildren}
-          bodyChildren={<WrappedComponent />}
-        />,
+        <WrappedComponent headChildren={headChildren} />,
         serverComponentManifest
       ).pipeThrough(createBufferedTransformStream())
     )
@@ -443,10 +452,7 @@ export async function renderToHTML(
   const bodyResult = async () => {
     const content = (
       <AppContainer>
-        <Component
-          headChildren={headChildren}
-          bodyChildren={<WrappedComponent />}
-        />
+        <Component headChildren={headChildren} />
       </AppContainer>
     )
 
diff --git a/test/e2e/views-dir/app/views/(newroot)/dashboard/another/page.server.js b/test/e2e/views-dir/app/views/(newroot)/dashboard/another/page.server.js
new file mode 100644
index 000000000000..f66225f1a78b
--- /dev/null
+++ b/test/e2e/views-dir/app/views/(newroot)/dashboard/another/page.server.js
@@ -0,0 +1,7 @@
+export default function AnotherPage(props) {
+  return (
+    <>
+      <p>hello from newroot/dashboard/another</p>
+    </>
+  )
+}
diff --git a/test/e2e/views-dir/app/views/(newroot)/layout.server.js b/test/e2e/views-dir/app/views/(newroot)/layout.server.js
new file mode 100644
index 000000000000..40352b78389e
--- /dev/null
+++ b/test/e2e/views-dir/app/views/(newroot)/layout.server.js
@@ -0,0 +1,19 @@
+export async function getServerSideProps() {
+  return {
+    props: {
+      world: 'world',
+    },
+  }
+}
+
+export default function Root({ headChildren, bodyChildren, world }) {
+  return (
+    <html className="this-is-another-document-html">
+      <head>
+        {headChildren}
+        <title>{`hello ${world}`}</title>
+      </head>
+      <body className="this-is-another-document-body">{bodyChildren}</body>
+    </html>
+  )
+}
diff --git a/test/e2e/views-dir/app/views/dashboard/(custom)/deployments/breakdown/page.server.js b/test/e2e/views-dir/app/views/dashboard/(custom)/deployments/breakdown/page.server.js
new file mode 100644
index 000000000000..a143e037ce55
--- /dev/null
+++ b/test/e2e/views-dir/app/views/dashboard/(custom)/deployments/breakdown/page.server.js
@@ -0,0 +1,7 @@
+export default function DeploymentsBreakdownPage(props) {
+  return (
+    <>
+      <p>hello from root/dashboard/(custom)/deployments/breakdown</p>
+    </>
+  )
+}
diff --git a/test/e2e/views-dir/app/views/dashboard/(custom)/layout.server.js b/test/e2e/views-dir/app/views/dashboard/(custom)/layout.server.js
new file mode 100644
index 000000000000..e861cd39c83c
--- /dev/null
+++ b/test/e2e/views-dir/app/views/dashboard/(custom)/layout.server.js
@@ -0,0 +1,8 @@
+export default function CustomDashboardRootLayout({ children }) {
+  return (
+    <>
+      <h2>Custom dashboard</h2>
+      {children}
+    </>
+  )
+}
diff --git a/test/e2e/views-dir/app/views/layout.server.js b/test/e2e/views-dir/app/views/layout.server.js
index d270310372cf..d74597727ddb 100644
--- a/test/e2e/views-dir/app/views/layout.server.js
+++ b/test/e2e/views-dir/app/views/layout.server.js
@@ -1,9 +1,17 @@
-export default function Root({ headChildren, bodyChildren }) {
+export async function getServerSideProps() {
+  return {
+    props: {
+      world: 'world',
+    },
+  }
+}
+
+export default function Root({ headChildren, bodyChildren, world }) {
   return (
     <html className="this-is-the-document-html">
       <head>
         {headChildren}
-        <title>Test</title>
+        <title>{`hello ${world}`}</title>
       </head>
       <body className="this-is-the-document-body">{bodyChildren}</body>
     </html>
diff --git a/test/e2e/views-dir/index.test.ts b/test/e2e/views-dir/index.test.ts
index 361613c99dfc..b1d1c052af59 100644
--- a/test/e2e/views-dir/index.test.ts
+++ b/test/e2e/views-dir/index.test.ts
@@ -26,6 +26,12 @@ describe('views dir', () => {
   })
   afterAll(() => next.destroy())
 
+  it('should pass props from getServerSideProps in root layout', async () => {
+    const html = await renderViaHTTP(next.url, '/dashboard')
+    const $ = cheerio.load(html)
+    expect($('title').text()).toBe('hello world')
+  })
+
   it('should serve from pages', async () => {
     const html = await renderViaHTTP(next.url, '/')
     expect(html).toContain('hello from pages/index')
@@ -55,14 +61,16 @@ describe('views dir', () => {
     expect($('p').text()).toBe('hello from root/dashboard/integrations')
   })
 
-  // TODO: why is this routable but /should-not-serve-server.server.js
   it('should not include parent when not in parent directory with route in directory', async () => {
     const html = await renderViaHTTP(next.url, '/dashboard/hello')
     const $ = cheerio.load(html)
 
-    // Should be nested in /root.js
-    expect($('html').hasClass('this-is-the-document-html')).toBeTruthy()
-    expect($('body').hasClass('this-is-the-document-body')).toBeTruthy()
+    // new root has to provide it's own custom root layout or the default
+    // is used instead
+    expect(html).toContain('<html>')
+    expect(html).toContain('<body>')
+    expect($('html').hasClass('this-is-the-document-html')).toBeFalsy()
+    expect($('body').hasClass('this-is-the-document-body')).toBeFalsy()
 
     // Should not be nested in dashboard
     expect($('h1').text()).toBeFalsy()
@@ -71,11 +79,48 @@ describe('views dir', () => {
     expect($('p').text()).toBe('hello from root/dashboard/rootonly/hello')
   })
 
+  it('should use new root layout when provided', async () => {
+    const html = await renderViaHTTP(next.url, '/dashboard/another')
+    const $ = cheerio.load(html)
+
+    // new root has to provide it's own custom root layout or the default
+    // is used instead
+    expect($('html').hasClass('this-is-another-document-html')).toBeTruthy()
+    expect($('body').hasClass('this-is-another-document-body')).toBeTruthy()
+
+    // Should not be nested in dashboard
+    expect($('h1').text()).toBeFalsy()
+
+    // Should render the page text
+    expect($('p').text()).toBe('hello from newroot/dashboard/another')
+  })
+
+  it('should not create new root layout when nested (optional)', async () => {
+    const html = await renderViaHTTP(
+      next.url,
+      '/dashboard/deployments/breakdown'
+    )
+    const $ = cheerio.load(html)
+
+    // new root has to provide it's own custom root layout or the default
+    // is used instead
+    expect($('html').hasClass('this-is-the-document-html')).toBeTruthy()
+    expect($('body').hasClass('this-is-the-document-body')).toBeTruthy()
+
+    // Should be nested in dashboard
+    expect($('h1').text()).toBe('Dashboard')
+    expect($('h2').text()).toBe('Custom dashboard')
+
+    // Should render the page text
+    expect($('p').text()).toBe(
+      'hello from root/dashboard/(custom)/deployments/breakdown'
+    )
+  })
+
   it('should include parent document when no direct parent layout', async () => {
     const html = await renderViaHTTP(next.url, '/dashboard/integrations')
     const $ = cheerio.load(html)
 
-    // Root has to provide it's own document
     expect($('html').hasClass('this-is-the-document-html')).toBeTruthy()
     expect($('body').hasClass('this-is-the-document-body')).toBeTruthy()
   })