http2: large queued request body prevents receiving an early response #66739

// A client that queues a large request body cannot read an early response.
// Cleartext HTTP/2 (h2c), no dependencies: `node repro.mjs`.
import http2 from 'node:http2';

const server = http2.createServer();
const sessions = new Set();
server.on('session', (session) => sessions.add(session));
server.on('stream', (stream) => {
  stream.on('error', () => {}); // the client may reset the stream
  // Reject without reading the request body, as a server does for a 401 or 413.
  stream.respond({ ':status': 413 });
  stream.end('payload too large');
});
await new Promise((resolve) => server.listen(0, resolve));
const origin = `http://localhost:${server.address().port}`;

const post = (bodyBytes, sessionOptions = {}) =>
  new Promise((resolve) => {
    const session = http2.connect(origin, sessionOptions);
    const req = session.request({ ':method': 'POST', ':path': '/' });
    req.on('response', (headers) => resolve(`status ${headers[':status']}`));
    req.on('error', (err) => resolve(`${err.code}: ${err.message}`));
    req.on('close', () => session.destroy());
    req.end(Buffer.alloc(bodyBytes)); // the whole body in one write
  });

const MiB = 1024 * 1024;
console.log(`node ${process.version}`);
console.log(' 8 MiB body:                   ', await post(8 * MiB));
console.log('16 MiB body:                   ', await post(16 * MiB));
console.log('16 MiB, maxSessionMemory 64 MB:', await post(16 * MiB, { maxSessionMemory: 64 }));
for (const session of sessions) session.destroy();
server.close();