vercel · ijjk · Oct 23, 2022 · Oct 19, 2022 · Oct 19, 2022 · Oct 20, 2022
@@ -1,4 +1,4 @@
-import * as React from 'react'
+import React from 'react'
 import {
   Dialog,
   DialogBody,
@@ -32,16 +32,16 @@ export const RootLayoutError: React.FC<RootLayoutErrorProps> =
           <DialogContent>
             <DialogHeader className="nextjs-container-root-layout-error-header">
               <h4 id="nextjs__container_root_layout_error_label">
-                Root layout error
+                Missing required tags
               </h4>
             </DialogHeader>
             <DialogBody className="nextjs-container-root-layout-error-body">
               <Terminal content={message} />
               <footer>
                 <p id="nextjs__container_root_layout_error_desc">
                   <small>
-                    This error occurred during the build process and can only be
-                    dismissed by fixing the error.
+                    This error and can only be dismissed by providing all
+                    required tags.
                   </small>
                 </p>
               </footer>

@@ -0,0 +1,85 @@
+import path from 'path'
+import { promises as fs } from 'fs'
+import chalk from 'next/dist/compiled/chalk'
+import * as Log from '../build/output/log'
+
+const globOrig =
+  require('next/dist/compiled/glob') as typeof import('next/dist/compiled/glob')
+const glob = (cwd: string, pattern: string): Promise<string[]> => {
+  return new Promise((resolve, reject) => {
+    globOrig(pattern, { cwd }, (err, files) => {
+      if (err) {
+        return reject(err)
+      }
+      resolve(files)
+    })
+  })
+}
+
+function getRootLayout(isTs: boolean) {
+  if (isTs) {
+    return `export default function RootLayout({
+  children,
+}: {
+  children: React.ReactNode
+}) {
+  return (
+    <html>
+      <head></head>
+      <body>{children}</body>
+    </html>
+  )
+}
+`
+  }
+
+  return `export default function RootLayout({ children }) {
+  return (
+    <html>
+      <head></head>
+      <body>{children}</body>
+    </html>
+  )
+}
+`
+}
+
+export async function verifyRootLayout({
+  dir,
+  appDir,
+  tsconfigPath,
+}: {
+  dir: string
+  appDir: string
+  tsconfigPath: string
+}) {
+  try {
+    // Only create root layout if no other layout exists
+    const layoutFiles = await glob(dir, 'app/**/layout.{js,jsx,ts,tsx}')
+    const hasLayout = layoutFiles.length !== 0
+    if (!hasLayout) {
+      const resolvedTsConfigPath = path.join(dir, tsconfigPath)
+      const hasTsConfig = await fs.access(resolvedTsConfigPath).then(
+        () => true,
+        () => false
+      )
+
+      const rootLayoutPath = path.join(
+        appDir,
+        `layout.${hasTsConfig ? 'tsx' : 'js'}`
+      )
+      await fs.writeFile(rootLayoutPath, getRootLayout(hasTsConfig))
+      console.log(
+        chalk.green(
+          `${chalk.bold(
+            'appDir'
+          )} is enabled but you're missing a root layout, we created ${chalk.bold(
+            `app/layout.${hasTsConfig ? 'tsx' : 'js'}`
+          )} for you.`
+        ) + '\n'
+      )
+    }
+  } catch (error) {
+    Log.error('Failed to create root layout', error)
+  }
+}
diff --git a/packages/next/server/dev/next-dev-server.ts b/packages/next/server/dev/next-dev-server.ts
@@ -26,6 +26,7 @@ import { findPagesDir } from '../../lib/find-pages-dir'
 import loadCustomRoutes from '../../lib/load-custom-routes'
 import { verifyTypeScriptSetup } from '../../lib/verifyTypeScriptSetup'
 import { verifyPartytownSetup } from '../../lib/verify-partytown-setup'
+import { verifyRootLayout } from '../../lib/verifyRootLayout'
 import {
   PHASE_DEVELOPMENT_SERVER,
   CLIENT_STATIC_FILES_PATH,
@@ -658,6 +659,13 @@ export default class DevServer extends Server {
     setGlobal('phase', PHASE_DEVELOPMENT_SERVER)
 
     await this.verifyTypeScript()
+    if (this.appDir) {
+      await verifyRootLayout({
+        dir: this.dir,
+        appDir: this.appDir,
+        tsconfigPath: this.nextConfig.typescript.tsconfigPath,
+      })
+    }
     this.customRoutes = await loadCustomRoutes(this.nextConfig)
 
     // reload router

@@ -0,0 +1,112 @@
+import path from 'path'
+import { createNext, FileRef } from 'e2e-utils'
+import { NextInstance } from 'test/lib/next-modes/base'
+import webdriver from 'next-webdriver'
+
+describe('app-dir create root layout', () => {
+  const isDev = (global as any).isNextDev
+
+  if (!isDev) {
+    it('should only run in dev', () => {})
+    return
+  }
+
+  if (process.env.NEXT_TEST_REACT_VERSION === '^17') {
+    it('should skip for react v17', () => {})
+    return
+  }
+  let next: NextInstance
+
+  describe('page.js', () => {
+    beforeAll(async () => {
+      next = await createNext({
+        files: {
+          'app/page.js': new FileRef(
+            path.join(__dirname, 'create-root-layout/app/page.js')
+          ),
+          'next.config.js': new FileRef(
+            path.join(__dirname, 'create-root-layout/next.config.js')
+          ),
+        },
+        dependencies: {
+          react: 'experimental',
+          'react-dom': 'experimental',
+        },
+      })
+    })
+    afterAll(() => next.destroy())
+
+    it('create root layout', async () => {
+      const outputIndex = next.cliOutput.length
+      const browser = await webdriver(next.url, '/')
+
+      expect(await browser.elementById('page-text').text()).toBe('Hello world!')
+
+      expect(next.cliOutput.slice(outputIndex)).toInclude(
+        "appDir is enabled but you're missing a root layout, we created app/layout.js for you."
+      )
+
+      expect(await next.readFile('app/layout.js')).toMatchInlineSnapshot(`
+        "export default function RootLayout({ children }) {
+          return (
+            <html>
+              <head></head>
+              <body>{children}</body>
+            </html>
+          )
+        }
+        "
+      `)
+    })
+  })
+
+  describe('page.tsx', () => {
+    beforeAll(async () => {
+      next = await createNext({
+        files: {
+          'app/page.tsx': new FileRef(
+            path.join(__dirname, 'create-root-layout/app/page.js')
+          ),
+          'next.config.js': new FileRef(
+            path.join(__dirname, 'create-root-layout/next.config.js')
+          ),
+        },
+        dependencies: {
+          react: 'experimental',
+          'react-dom': 'experimental',
+          typescript: 'latest',
+          '@types/react': 'latest',
+          '@types/node': 'latest',
+        },
+      })
+    })
+    afterAll(() => next.destroy())
+
+    it('create root layout', async () => {
+      const outputIndex = next.cliOutput.length
+      const browser = await webdriver(next.url, '/')
+
+      expect(await browser.elementById('page-text').text()).toBe('Hello world!')
+
+      expect(next.cliOutput.slice(outputIndex)).toInclude(
+        "appDir is enabled but you're missing a root layout, we created app/layout.tsx for you."
+      )
+
+      expect(await next.readFile('app/layout.tsx')).toMatchInlineSnapshot(`
+        "export default function RootLayout({
+          children,
+        }: {
+          children: React.ReactNode
+        }) {
+          return (
+            <html>
+              <head></head>
+              <body>{children}</body>
+            </html>
+          )
+        }
+        "
+      `)
+    })
+  })
+})
@@ -0,0 +1,3 @@
+export default function Page() {
+  return <p id="page-text">Hello world!</p>
+}
@@ -0,0 +1,5 @@
+module.exports = {
+  experimental: {
+    appDir: true,
+  },
+}