Fix cross-worker revalidate API (#49101)

Currently we invoke the revalidate request directly in the current
server when `res.revalidate()` is called. However app needs to be
rendered in a separate worker so this results in an error of React. This
PR fixes it by sending the request via IPC so the main process will
delegate that to the correct render worker.

Closes #48948.

---------

Co-authored-by: JJ Kasper <jj@jjsweb.site>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/next/src/server/api-utils/node.ts

@@ -27,7 +27,6 @@ import {
   SYMBOL_PREVIEW_DATA,
   RESPONSE_LIMIT_DEFAULT,
 } from './index'
-import { createRequestResponseMocks } from '../lib/mock-request'
 import { getTracer } from '../lib/trace/tracer'
 import { NodeSpan } from '../lib/trace/constants'
 import { RequestCookies } from '../web/spec-extension/cookies'
@@ -36,6 +35,7 @@ import {
   PRERENDER_REVALIDATE_HEADER,
   PRERENDER_REVALIDATE_ONLY_GENERATED_HEADER,
 } from '../../lib/constants'
+import { invokeRequest } from '../lib/server-ipc'
 
 export function tryGetPreviewData(
   req: IncomingMessage | BaseNextRequest | Request,
@@ -194,7 +194,14 @@ export async function parseBody(
 type ApiContext = __ApiPreviewProps & {
   trustHostHeader?: boolean
   allowedRevalidateHeaderKeys?: string[]
-  revalidate?: (_req: IncomingMessage, _res: ServerResponse) => Promise<any>
+  hostname?: string
+  revalidate?: (config: {
+    urlPath: string
+    revalidateHeaders: { [key: string]: string | string[] }
+    opts: { unstable_onlyGenerated?: boolean }
+  }) => Promise<any>
+
+  // (_req: IncomingMessage, _res: ServerResponse) => Promise<any>
 }
 
 function getMaxContentLength(responseLimit?: ResponseLimit) {
@@ -453,20 +460,44 @@ async function revalidate(
         throw new Error(`Invalid response ${res.status}`)
       }
     } else if (context.revalidate) {
-      const mocked = createRequestResponseMocks({
-        url: urlPath,
-        headers: revalidateHeaders,
-      })
+      // We prefer to use the IPC call if running under the workers mode.
+      const ipcPort = process.env.__NEXT_PRIVATE_ROUTER_IPC_PORT
+      if (ipcPort) {
+        const ipcKey = process.env.__NEXT_PRIVATE_ROUTER_IPC_KEY
+        const res = await invokeRequest(
+          `http://${
+            context.hostname
+          }:${ipcPort}?key=${ipcKey}&method=revalidate&args=${encodeURIComponent(
+            JSON.stringify([{ urlPath, revalidateHeaders }])
+          )}`,
+          {
+            method: 'GET',
+            headers: {},
+          }
+        )
 
-      await context.revalidate(mocked.req, mocked.res)
-      await mocked.res.hasStreamed
+        const chunks = []
 
-      if (
-        mocked.res.getHeader('x-nextjs-cache') !== 'REVALIDATED' &&
-        !(mocked.res.statusCode === 404 && opts.unstable_onlyGenerated)
-      ) {
-        throw new Error(`Invalid response ${mocked.res.statusCode}`)
+        for await (const chunk of res) {
+          if (chunk) {
+            chunks.push(chunk)
+          }
+        }
+        const body = Buffer.concat(chunks).toString()
+        const result = JSON.parse(body)
+
+        if (result.err) {
+          throw new Error(result.err.message)
+        }
+
+        return
       }
+
+      await context.revalidate({
+        urlPath,
+        revalidateHeaders,
+        opts,
+      })
     } else {
       throw new Error(
         `Invariant: required internal revalidate method not passed to api-utils`

packages/next/src/server/next-server.ts

@@ -107,6 +107,7 @@ import { removePathPrefix } from '../shared/lib/router/utils/remove-path-prefix'
 import { addPathPrefix } from '../shared/lib/router/utils/add-path-prefix'
 import { pathHasPrefix } from '../shared/lib/router/utils/path-has-prefix'
 import { filterReqHeaders, invokeRequest } from './lib/server-ipc'
+import { createRequestResponseMocks } from './lib/mock-request'
 
 export * from './base-server'
 
@@ -906,16 +907,13 @@ export default class NextNodeServer extends BaseServer {
       pageModule,
       {
         ...this.renderOpts.previewProps,
-        revalidate: (newReq: IncomingMessage, newRes: ServerResponse) =>
-          this.getRequestHandler()(
-            new NodeNextRequest(newReq),
-            new NodeNextResponse(newRes)
-          ),
+        revalidate: this.revalidate.bind(this),
         // internal config so is not typed
         trustHostHeader: (this.nextConfig.experimental as Record<string, any>)
           .trustHostHeader,
         allowedRevalidateHeaderKeys:
           this.nextConfig.experimental.allowedRevalidateHeaderKeys,
+        hostname: this.hostname,
       },
       this.minimalMode,
       this.renderOpts.dev,
@@ -1672,6 +1670,36 @@ export default class NextNodeServer extends BaseServer {
     }
   }
 
+  public async revalidate({
+    urlPath,
+    revalidateHeaders,
+    opts,
+  }: {
+    urlPath: string
+    revalidateHeaders: { [key: string]: string | string[] }
+    opts: { unstable_onlyGenerated?: boolean }
+  }) {
+    const mocked = createRequestResponseMocks({
+      url: urlPath,
+      headers: revalidateHeaders,
+    })
+
+    const handler = this.getRequestHandler()
+    await handler(
+      new NodeNextRequest(mocked.req),
+      new NodeNextResponse(mocked.res)
+    )
+    await mocked.res.hasStreamed
+
+    if (
+      mocked.res.getHeader('x-nextjs-cache') !== 'REVALIDATED' &&
+      !(mocked.res.statusCode === 404 && opts.unstable_onlyGenerated)
+    ) {
+      throw new Error(`Invalid response ${mocked.res.statusCode}`)
+    }
+    return {}
+  }
+
   public async render(
     req: BaseNextRequest | IncomingMessage,
     res: BaseNextResponse | ServerResponse,

test/production/app-dir/revalidate/app/layout.js

@@ -0,0 +1,7 @@
+export default function Root({ children }) {
+  return (
+    <html>
+      <body>{children}</body>
+    </html>
+  )
+}

test/production/app-dir/revalidate/app/page.js

@@ -0,0 +1,4 @@
+export default async function Page() {
+  const data = Math.random()
+  return <h1>{data}</h1>
+}

test/production/app-dir/revalidate/next.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  experimental: {
+    appDir: true,
+  },
+}

test/production/app-dir/revalidate/pages/api/revalidate.js

@@ -0,0 +1,8 @@
+export default async function (_req, res) {
+  try {
+    await res.revalidate('/')
+    return res.json({ revalidated: true })
+  } catch (err) {
+    return res.status(500).send('Error')
+  }
+}

test/production/app-dir/revalidate/revalidate.test.ts

@@ -0,0 +1,20 @@
+import { createNextDescribe } from 'e2e-utils'
+
+createNextDescribe(
+  'app-dir revalidate',
+  {
+    files: __dirname,
+    skipDeployment: true,
+  },
+  ({ next }) => {
+    it('should be able to revalidate the cache via pages/api', async () => {
+      const $ = await next.render$('/')
+      const id = $('h1').text()
+      const res = await next.fetch('/api/revalidate')
+      expect(res.status).toBe(200)
+      const $2 = await next.render$('/')
+      const id2 = $2('h1').text()
+      expect(id).not.toBe(id2)
+    })
+  }
+)