Render resolved streaming content for static render result

packages/next/server/web-server.ts

@@ -131,7 +131,6 @@ export default class NextWebServer extends BaseServer {
       query,
       {
         ...renderOpts,
-        // supportsDynamicHTML: true,
         disableOptimizedLoading: true,
         runtime: 'edge',
       }

packages/next/server/web/sandbox/readable-stream.ts

@@ -39,17 +39,17 @@ class ReadableStream<T> {
 
     const pull = () => {
       if (opts.pull) {
-        if (!pullPromise) {
+        const shouldPull =
+          controller.desiredSize !== null && controller.desiredSize > 0
+        if (!pullPromise && shouldPull) {
           pullPromise = Promise.resolve().then(() => {
             pullPromise = 0
             opts.pull!(controller)
           })
+          return pullPromise
         }
       }
-    }
-
-    if (opts.start) {
-      opts.start(controller)
+      return Promise.resolve()
     }
 
     if (opts.cancel) {
@@ -59,7 +59,20 @@ class ReadableStream<T> {
       }
     }
 
-    pull()
+    function registerPull() {
+      const getReader = readable.getReader.bind(readable)
+      readable.getReader = () => {
+        pull()
+        return getReader()
+      }
+    }
+
+    const started = opts.start && opts.start(controller)
+    if (started && typeof started.then === 'function') {
+      started.then(() => registerPull())
+    } else {
+      registerPull()
+    }
 
     return readable
   }

test/integration/react-streaming-and-server-components/test/basic.js

@@ -54,4 +54,13 @@ export default async function basic(context, { env }) {
     const html = await renderViaHTTP(context.appPort, '/err/suspense')
     expect(html).toContain('error-fallback')
   })
+
+  it('should support React.lazy and dynamic imports', async () => {
+    const html = await renderViaHTTP(context.appPort, '/dynamic-imports')
+    expect(html).toContain('foo.client')
+
+    const browser = await webdriver(context.appPort, '/dynamic-imports')
+    const content = await browser.eval(`window.document.body.innerText`)
+    expect(content).toMatchInlineSnapshot('"foo.client"')
+  })
 }

test/integration/react-streaming-and-server-components/test/index.test.js

@@ -2,7 +2,6 @@
 
 import { join } from 'path'
 import fs from 'fs-extra'
-import webdriver from 'next-webdriver'
 
 import { fetchViaHTTP, findPort, killApp, renderViaHTTP } from 'next-test-utils'
 
@@ -146,11 +145,6 @@ describe('Edge runtime - prod', () => {
     expect(content.clientInfo).not.toContainEqual([['/404', true]])
   })
 
-  it('should support React.lazy and dynamic imports', async () => {
-    const html = await renderViaHTTP(context.appPort, '/dynamic-imports')
-    expect(html).toContain('foo.client')
-  })
-
   const options = { runtime: 'edge', env: 'prod' }
   basic(context, options)
   streaming(context, options)
@@ -171,15 +165,6 @@ describe('Edge runtime - dev', () => {
     await killApp(context.server)
   })
 
-  it('should support React.lazy and dynamic imports', async () => {
-    const html = await renderViaHTTP(context.appPort, '/dynamic-imports')
-    expect(html).toContain('loading...')
-
-    const browser = await webdriver(context.appPort, '/dynamic-imports')
-    const content = await browser.eval(`window.document.body.innerText`)
-    expect(content).toMatchInlineSnapshot('"foo.client"')
-  })
-
   it('should have content-type and content-encoding headers', async () => {
     const res = await fetchViaHTTP(context.appPort, '/')
     expect(res.headers.get('content-type')).toBe('text/html; charset=utf-8')

test/integration/react-streaming-and-server-components/test/rsc.js

@@ -1,16 +1,9 @@
 /* eslint-env jest */
 import webdriver from 'next-webdriver'
-import cheerio from 'cheerio'
 import { renderViaHTTP, check } from 'next-test-utils'
 import { join } from 'path'
 import fs from 'fs-extra'
-
-import { distDir } from './utils'
-
-function getNodeBySelector(html, selector) {
-  const $ = cheerio.load(html)
-  return $(selector)
-}
+import { distDir, getNodeBySelector } from './utils'
 
 export default function (context, { runtime, env }) {
   it('should render server components correctly', async () => {

test/integration/react-streaming-and-server-components/test/streaming.js

@@ -1,6 +1,7 @@
 /* eslint-env jest */
 import webdriver from 'next-webdriver'
 import { fetchViaHTTP, waitFor } from 'next-test-utils'
+import { getNodeBySelector } from './utils'
 
 async function resolveStreamResponse(response, onData) {
   let result = ''
@@ -218,6 +219,10 @@ export default function (context, { env, runtime }) {
       flushCount++
     })
     expect(flushCount).toBe(1)
+    const html = await res1.text()
+    const body = await getNodeBySelector(html, '#__next')
+    // Resolve data instead of fallback
+    expect(body.text()).toBe('next_streaming_data')
 
     if (runtime === 'nodejs') {
       expect(res1.headers.get('etag')).toBeDefined()

test/integration/react-streaming-and-server-components/test/utils.js

@@ -5,6 +5,7 @@ import {
   nextBuild as _nextBuild,
   nextStart as _nextStart,
 } from 'next-test-utils'
+import cheerio from 'cheerio'
 
 const nodeArgs = ['-r', join(__dirname, '../../react-18/test/require-hook.js')]
 
@@ -44,3 +45,8 @@ export async function nextDev(dir, port) {
     nodeArgs,
   })
 }
+
+export function getNodeBySelector(html, selector) {
+  const $ = cheerio.load(html)
+  return $(selector)
+}