Error in next export when serverActions is enabled (vercel#50039)

Reland vercel#49959 as it was reverted in vercel#50019

* Only error when runing `next export` or `output` is "export"
* Add e2e test


Closes NEXT-634

packages/next/src/build/index.ts

@@ -3101,6 +3101,7 @@ export default async function build(
 
         const options: ExportOptions = {
           isInvokedFromCli: false,
+          buildExport: false,
           nextConfig: config,
           hasAppDir,
           silent: true,

packages/next/src/cli/next-export.ts

@@ -2,7 +2,7 @@
 import { resolve, join } from 'path'
 import { existsSync } from 'fs'
 import arg from 'next/dist/compiled/arg/index.js'
-import exportApp, { ExportError } from '../export'
+import exportApp, { ExportError, ExportOptions } from '../export'
 import * as Log from '../build/output/log'
 import { printAndExit } from '../server/lib/utils'
 import { CliCommand } from '../lib/commands'
@@ -59,12 +59,13 @@ const nextExport: CliCommand = (argv) => {
     printAndExit(`> No such directory exists as the project root: ${dir}`)
   }
 
-  const options = {
+  const options: ExportOptions = {
     silent: args['--silent'] || false,
     threads: args['--threads'],
     outdir: args['--outdir'] ? resolve(args['--outdir']) : join(dir, 'out'),
     isInvokedFromCli: true,
     hasAppDir: false,
+    buildExport: false,
   }
 
   exportApp(dir, options, nextExportCliSpan)

packages/next/src/export/index.ts

@@ -148,7 +148,7 @@ export interface ExportOptions {
   threads?: number
   debugOutput?: boolean
   pages?: string[]
-  buildExport?: boolean
+  buildExport: boolean
   statusMessage?: string
   exportPageWorker?: typeof import('./worker').default
   exportAppPageWorker?: typeof import('./worker').default
@@ -179,9 +179,11 @@ export default async function exportApp(
 
     const threads = options.threads || nextConfig.experimental.cpus
     const distDir = join(dir, nextConfig.distDir)
+    const isExportOutput = nextConfig.output === 'export'
 
+    // Running 'next export'
     if (options.isInvokedFromCli) {
-      if (nextConfig.output === 'export') {
+      if (isExportOutput) {
         Log.warn(
           '"next export" is no longer needed when "output: export" is configured in next.config.js https://nextjs.org/docs/advanced-features/static-html-export'
         )
@@ -196,6 +198,14 @@ export default async function exportApp(
         '"next export" is deprecated in favor of "output: export" in next.config.js https://nextjs.org/docs/advanced-features/static-html-export'
       )
     }
+    // Running 'next export' or output is set to 'export'
+    if (options.isInvokedFromCli || isExportOutput) {
+      if (nextConfig.experimental.serverActions) {
+        throw new ExportError(
+          `Server Actions are not supported with static export.`
+        )
+      }
+    }
 
     const telemetry = options.buildExport ? null : new Telemetry({ distDir })
 

packages/next/src/lib/metadata/resolve-metadata.test.ts

@@ -126,7 +126,6 @@ describe('accumulateMetadata', () => {
         [{ themeColor: '#fff' }, null],
       ]
       const metadata = await accumulateMetadata(metadataItems)
-      console.log('xxmetadata', metadata.themeColor)
       expect(metadata).toMatchObject({
         themeColor: [{ color: '#fff' }],
       })

test/e2e/app-dir/actions/app-action-export.test.ts

@@ -0,0 +1,40 @@
+import { createNextDescribe } from 'e2e-utils'
+
+createNextDescribe(
+  'app-dir action handling - next export',
+  {
+    files: __dirname,
+    skipStart: true,
+    skipDeployment: true,
+  },
+  ({ next, isNextStart }) => {
+    if (!isNextStart) {
+      it('skip test for dev mode', () => {})
+      return
+    }
+
+    beforeAll(async () => {
+      await next.stop()
+      await next.patchFile(
+        'next.config.js',
+        `
+      module.exports = {
+        output: 'export',
+        experimental: {
+          serverActions: true,
+        },
+      }
+      `
+      )
+      try {
+        await next.start()
+      } catch {}
+    })
+
+    it('should error when use export output for server actions', async () => {
+      expect(next.cliOutput).toContain(
+        `Server Actions are not supported with static export.`
+      )
+    })
+  }
+)

test/lib/next-modes/next-dev.ts

@@ -3,7 +3,7 @@ import { Span } from 'next/src/trace'
 import { NextInstance } from './base'
 
 export class NextDevInstance extends NextInstance {
-  private _cliOutput: string
+  private _cliOutput: string = ''
 
   public get buildId() {
     return 'development'

test/lib/next-modes/next-start.ts

@@ -6,7 +6,7 @@ import { Span } from 'next/src/trace'
 
 export class NextStartInstance extends NextInstance {
   private _buildId: string
-  private _cliOutput: string
+  private _cliOutput: string = ''
   private spawnOpts: SpawnOptions
 
   public get buildId() {
@@ -53,6 +53,7 @@ export class NextStartInstance extends NextInstance {
         __NEXT_TEST_MODE: 'e2e',
       },
     }
+
     let buildArgs = ['yarn', 'next', 'build']
     let startArgs = ['yarn', 'next', 'start']