Move the WebTransport headers test to external/wpt

R=flackr@chromium.org, ricea@chromium.org

Change-Id: I844c3180fccad46b0f0120467c2a71dc4e3f085a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8265548
Reviewed-by: Adam Rice <ricea@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1682887}

Author: aran

webtransport/headers.https.any.js

@@ -0,0 +1,127 @@
+// META: global=window,worker
+// META: script=/webtransport/resources/webtransport-test-helpers.sub.js
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('echo-request-headers.py'));
+  t.add_cleanup(() => wt.close());
+  assert_equals(wt.responseHeaders, null,
+                'responseHeaders is null synchronously after construction');
+  await wt.ready;
+}, 'responseHeaders is null before the connection is established');
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('echo-request-headers.py'));
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+  assert_true(wt.responseHeaders instanceof Headers,
+              'responseHeaders is a Headers object after ready');
+}, 'responseHeaders is a Headers object after ready resolves');
+
+promise_test(async t => {
+  const wt = new WebTransport(
+      webtransport_url('custom-response.py?x-test-header=hello&x-other=world'));
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+  assert_equals(wt.responseHeaders.get('x-test-header'), 'hello');
+  assert_equals(wt.responseHeaders.get('x-other'), 'world');
+}, 'responseHeaders exposes server-sent response headers');
+
+promise_test(async t => {
+  const wt =
+      new WebTransport(webtransport_url('custom-response.py?wt-protocol=foo'));
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+  assert_false(wt.responseHeaders.has('wt-protocol'),
+               'wt-protocol must be stripped from responseHeaders');
+}, 'wt-protocol is stripped from responseHeaders');
+
+promise_test(async t => {
+  // https://fetch.spec.whatwg.org/#forbidden-response-header-name
+  const wt = new WebTransport(
+      webtransport_url('custom-response.py?set-cookie=probe%3D1'));
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+  assert_false(
+      wt.responseHeaders.has('set-cookie'),
+      'Set-Cookie must not be exposed via WebTransport.responseHeaders');
+}, 'Set-Cookie is stripped from responseHeaders');
+
+promise_test(async t => {
+  const wt = new WebTransport(webtransport_url('echo-request-headers.py'),
+                              {headers: {'x-client-header': 'sent'}});
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+
+  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);
+
+  // HTTP/3 requires lowercase field names (RFC 9114 §4.2), so the header
+  // should arrive at the server lowercased regardless of the source casing.
+  assert_equals(request_headers['x-client-header'], 'sent',
+                'custom header forwarded to the server');
+  assert_equals(request_headers['X-Client-Header'], undefined,
+                'custom header is not forwarded with the original casing');
+}, 'headers option forwards a custom header to the server, lowercased');
+
+promise_test(async t => {
+  // Cookie is on the Fetch forbidden request-header list; per Fetch spec it
+  // is silently dropped rather than throwing, so the connection succeeds but
+  // the header must not reach the server.
+  const wt = new WebTransport(webtransport_url('echo-request-headers.py'),
+                              {headers: {'Cookie': 'probe=forbidden'}});
+  t.add_cleanup(() => wt.close());
+  await wt.ready;
+
+  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);
+
+  assert_not_equals(
+      request_headers['cookie'], 'probe=forbidden',
+      'user-supplied Cookie must be silently dropped, not forwarded');
+}, 'Forbidden request-header names are silently dropped from the headers option');
+
+test(() => {
+  assert_throws_js(TypeError, () => new WebTransport('https://localhost:0/', {
+                                headers: {'wt-available-protocols': 'test'}
+                              }));
+}, 'wt-available-protocols header throws TypeError');
+
+test(() => {
+  assert_throws_js(TypeError, () => new WebTransport('https://localhost:0/', {
+                                headers: {'WT-Available-Protocols': 'test'}
+                              }));
+}, 'wt-available-protocols header throws TypeError (upper case)');
+
+test(() => {
+  assert_throws_js(TypeError, () => new WebTransport('https://localhost:0/', {
+                                headers: {'Wt-AVAILABLE-protocols': 'test'}
+                              }));
+}, 'wt-available-protocols header throws TypeError (mixed case)');
+
+function constructAndClose(options) {
+  const wt = new WebTransport('https://localhost:0/', options);
+  // Swallow the unhandled rejections from the unreachable URL.
+  wt.ready.catch(() => {});
+  wt.closed.catch(() => {});
+  wt.close();
+}
+
+test(() => {
+  constructAndClose({headers: [['x-foo', 'bar'], ['x-baz', 'qux']]});
+}, 'HeadersInit sequence-of-sequences form is accepted');
+
+test(() => {
+  constructAndClose({headers: [['x-dup', 'one'], ['x-dup', 'two']]});
+}, 'Duplicate header names in sequence form are accepted');
+
+test(() => {
+  assert_throws_js(TypeError,
+                   () => new WebTransport('https://localhost:0/',
+                                          {headers: [['only-one-element']]}));
+}, 'HeadersInit sequence with wrong inner length throws TypeError');