feat(examples)+test(e2e): streaming SSR demo, proven progressive in Chromium

examples/streaming is a runnable Node server piping toStream() through Readable.fromWeb. The e2e server gains /stream, and two tests prove real streaming: shell bytes arrive over HTTP before the async hole resolves, and Chromium builds the shell DOM mid-stream, then grows the slow section into the same document without navigation. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014NgfSjHE11oFpoSnLVKLXd
2026-09-08 18:44:52 +02:00
parent 22c5045c25
commit d22f996596
4 changed files with 134 additions and 0 deletions
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+// Streaming SSR demo: the shell flushes immediately, the slow section
+// streams in when its promise resolves. Run it:
+//   node examples/streaming/server.js
+//
+// This page is server-rendered only (no hydration script): async holes
+// stream on the server, while client-side views must be synchronous.
+// Serializing streamed state for hydration is bankai v10 territory.
+
+import choo from '@choojs/core'
+import html from '@choojs/html'
+
+const wait = (ms) => new Promise((resolve) => setTimeout(resolve, ms))
+
+export default function createApp ({ delay = 500 } = {}) {
+  const app = choo()
+  app.use((state) => { state.delay = delay })
+  app.route('/', mainView)
+  app.route('*', mainView)
+  return app
+}
+
+function mainView (state, emit) {
+  return html`
+    <body>
+      <h1>choo streams</h1>
+      <p>This shell was flushed before the slow part finished.</p>
+      ${slowSection(state)}
+    </body>
+  `
+}
+
+async function slowSection (state) {
+  await wait(state.delay)
+  return html`<section id="slow">…and this arrived ${state.delay}ms later, same response.</section>`
+}
@@ -0,0 +1,27 @@
+// Minimal streaming SSR server on plain Node http.
+//   node examples/streaming/server.js
+// The same ReadableStream plugs into web-standard servers as
+// `new Response(app.toStream('/'))` — Readable.fromWeb is just the
+// Node http bridge.
+
+import { createServer } from 'node:http'
+import { Readable } from 'node:stream'
+
+import createApp from './app.js'
+
+const PORT = process.env.PORT || 8080
+
+createServer((req, res) => {
+  res.writeHead(200, { 'content-type': 'text/html; charset=utf-8' })
+  res.write('<!doctype html>\n<html lang="en">\n<head><meta charset="utf-8"><title>choo streams</title></head>\n')
+
+  const body = Readable.fromWeb(createApp().toStream('/'))
+  body.pipe(res, { end: false })
+  body.on('end', () => res.end('\n</html>'))
+  body.on('error', (err) => {
+    console.error(err)
+    res.destroy()
+  })
+}).listen(PORT, () => {
+  console.log(`streaming on http://localhost:${PORT} — watch the slow section arrive`)
+})