Add CONNECT response WPTs for WebTransport

This CL adds 7 test cases:
- establish WebTransport connection with different status codes
- echo the CONNECT request headers
- setting a cookie in a CONNECT request, and then making sure the
"cookie" header is not echoed back

The echo-request-headers server handler is also added in this CL, which
sends the CONNECT request headers over a unidirectional stream.

Bug: 1201569
Change-Id: I30d8092af42dc2505cadbc15bf0573f8815758bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3134980
Commit-Queue: Nidhi Jaju <nidhijaju@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/main@{#918651}

webtransport/connect.sub.any.js

@@ -0,0 +1,73 @@
+// META: global=window,worker
+// META: script=/common/get-host-info.sub.js
+// META: script=resources/webtransport-test-helpers.sub.js
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('custom-response.py?:status=200'));
+  await wt.ready;
+}, 'WebTransport connection succeeds with status code 200');
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('custom-response.py?:status=204'));
+  await wt.ready;
+}, 'WebTransport connection succeeds with status code 204');
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('custom-response.py?:status=301'));
+  await promise_rejects_js(t, TypeError, wt.ready, 'ready promise shoud be rejected');
+  await promise_rejects_js(t, TypeError, wt.closed, 'closed promise should be rejected');
+}, 'WebTransport connection fails with status code 301');
+
+promise_test(async t => {
+  const  wt = new WebTransport(webtransport_url('custom-response.py?:status=401'));
+  await promise_rejects_js(t, TypeError, wt.ready, 'ready promise should be rejected');
+  await promise_rejects_js(t, TypeError, wt.closed, 'closed promise should be rejected');
+}, 'WebTransport connection fails with status code 401');
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('custom-response.py?:status=404'));
+  await promise_rejects_js(t, TypeError, wt.ready, 'ready promise should be rejected');
+  await promise_rejects_js(t, TypeError, wt.closed, 'closed promise should be rejected');
+}, 'WebTransport connection fails with status code 404');
+
+promise_test(async t => {
+  // Create WebTransport session.
+  const wt = new WebTransport(webtransport_url('echo-request-headers.py'));
+  await wt.ready;
+
+  // Read incoming unidirectional stream for echoed request headers.
+  const streams = await wt.incomingUnidirectionalStreams;
+
+  const stream_reader = streams.getReader();
+  const { value: recv_stream } = await stream_reader.read();
+  stream_reader.releaseLock();
+
+  const request_headers = await read_stream_as_json(recv_stream);
+
+  // Check the standard request headers.
+  check_and_remove_standard_headers(request_headers);
+}, 'Echo back request headers');
+
+promise_test(async t => {
+  // Create WebTransport session, and attach "Set-Cookie: foo=bar" to the response of
+  // the handshake.
+  const encodedSetCookie = encodeURIComponent('foo=bar');
+  let wt = new WebTransport(webtransport_url('custom-response.py?set-cookie=' + encodedSetCookie));
+  await wt.ready;
+
+  wt = new WebTransport(webtransport_url('echo-request-headers.py'));
+  await wt.ready;
+
+  // Read incoming unidirectional stream for echoed request headers.
+  const streams = await wt.incomingUnidirectionalStreams;
+
+  const stream_reader = streams.getReader();
+  const { value: recv_stream } = await stream_reader.read();
+  stream_reader.releaseLock();
+
+  const request_headers = await read_stream_as_json(recv_stream);
+
+  // Check cookie header is not echoed back.
+  check_and_remove_standard_headers(request_headers);
+  assert_equals(request_headers['cookie'], undefined);
+}, 'Cookie header is not echoed back');

webtransport/handlers/echo-request-headers.py

@@ -0,0 +1,11 @@
+import json
+
+
+def session_established(session):
+    headers = {}
+    for name, value in session.request_headers:
+        headers[name.decode('utf-8')] = value.decode('utf-8')
+
+    stream_id = session.create_unidirectional_stream()
+    data = json.dumps(headers).encode('utf-8')
+    session.send_stream_data(stream_id, data, end_stream=True)

webtransport/resources/webtransport-test-helpers.sub.js

@@ -0,0 +1,49 @@
+// The file including this must also include /common/get-host-info.sub.js to
+// pick up the necessary constants.
+
+const HOST = get_host_info().ORIGINAL_HOST;
+const PORT = '{{ports[webtransport-h3][0]}}';
+const BASE = `https://${HOST}:${PORT}`;
+
+// Create URL for WebTransport session.
+function webtransport_url(handler) {
+  return `${BASE}/webtransport/handlers/${handler}`;
+}
+
+// Decode all chunks in a given ReadableStream.
+async function read_stream_as_json(stream) {
+  const decoder = new TextDecoderStream('utf-8');
+  const decode_stream = stream.readable.pipeThrough(decoder);
+  const reader = decode_stream.getReader();
+
+  let chunks = '';
+  while (true) {
+    const {value: chunk, done} = await reader.read();
+    if (done) {
+      break;
+    }
+    chunks += chunk;
+  }
+  reader.releaseLock();
+
+  return JSON.parse(chunks);
+}
+
+// Check the standard request headers and delete them, leaving any "unique"
+// headers to check in the test.
+function check_and_remove_standard_headers(headers) {
+  assert_equals(headers[':scheme'], 'https');
+  delete headers[':scheme'];
+  assert_equals(headers[':method'], 'CONNECT');
+  delete headers[':method'];
+  assert_equals(headers[':authority'], `${HOST}:${PORT}`);
+  delete headers[':authority'];
+  assert_equals(headers[':path'], '/webtransport/handlers/echo-request-headers.py');
+  delete headers[':path'];
+  assert_equals(headers[':protocol'], 'webtransport');
+  delete headers[':protocol'];
+  assert_equals(headers['origin'], `${get_host_info().ORIGIN}`);
+  delete headers['origin'];
+  assert_equals(headers['datagram-flow-id'], '0');
+  delete headers['datagram-flow-id'];
+}