Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 936 insertions, 0 deletions

diff --git a/testing/web-platform/tests/streams/readable-byte-streams/tee.any.js b/testing/web-platform/tests/streams/readable-byte-streams/tee.any.js
new file mode 100644
index 0000000000..7dd5ba3f3f
--- /dev/null
+++ b/testing/web-platform/tests/streams/readable-byte-streams/tee.any.js
@@ -0,0 +1,936 @@
+// META: global=window,worker,shadowrealm
+// META: script=../resources/rs-utils.js
+// META: script=../resources/test-utils.js
+// META: script=../resources/recording-streams.js
+// META: script=../resources/rs-test-templates.js
+'use strict';
+
+test(() => {
+
+  const rs = new ReadableStream({ type: 'bytes' });
+  const result = rs.tee();
+
+  assert_true(Array.isArray(result), 'return value should be an array');
+  assert_equals(result.length, 2, 'array should have length 2');
+  assert_equals(result[0].constructor, ReadableStream, '0th element should be a ReadableStream');
+  assert_equals(result[1].constructor, ReadableStream, '1st element should be a ReadableStream');
+
+}, 'ReadableStream teeing with byte source: rs.tee() returns an array of two ReadableStreams');
+
+promise_test(async t => {
+
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      c.enqueue(new Uint8Array([0x01]));
+      c.enqueue(new Uint8Array([0x02]));
+      c.close();
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+
+  reader2.closed.then(t.unreached_func('branch2 should not be closed'));
+
+  {
+    const result = await reader1.read(new Uint8Array(1));
+    assert_equals(result.done, false, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x01]), 'value');
+  }
+
+  {
+    const result = await reader1.read(new Uint8Array(1));
+    assert_equals(result.done, false, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x02]), 'value');
+  }
+
+  {
+    const result = await reader1.read(new Uint8Array(1));
+    assert_equals(result.done, true, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0]).subarray(0, 0), 'value');
+  }
+
+  {
+    const result = await reader2.read(new Uint8Array(1));
+    assert_equals(result.done, false, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x01]), 'value');
+  }
+
+  await reader1.closed;
+
+}, 'ReadableStream teeing with byte source: should be able to read one branch to the end without affecting the other');
+
+promise_test(async () => {
+
+  let pullCount = 0;
+  const enqueuedChunk = new Uint8Array([0x01]);
+  const rs = new ReadableStream({
+    type: 'bytes',
+    pull(c) {
+      ++pullCount;
+      if (pullCount === 1) {
+        c.enqueue(enqueuedChunk);
+      }
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader();
+  const reader2 = branch2.getReader();
+
+  const [result1, result2] = await Promise.all([reader1.read(), reader2.read()]);
+  assert_equals(result1.done, false, 'reader1 done');
+  assert_equals(result2.done, false, 'reader2 done');
+
+  const view1 = result1.value;
+  const view2 = result2.value;
+  assert_typed_array_equals(view1, new Uint8Array([0x01]), 'reader1 value');
+  assert_typed_array_equals(view2, new Uint8Array([0x01]), 'reader2 value');
+
+  assert_not_equals(view1.buffer, view2.buffer, 'chunks should have different buffers');
+  assert_not_equals(enqueuedChunk.buffer, view1.buffer, 'enqueued chunk and branch1\'s chunk should have different buffers');
+  assert_not_equals(enqueuedChunk.buffer, view2.buffer, 'enqueued chunk and branch2\'s chunk should have different buffers');
+
+}, 'ReadableStream teeing with byte source: chunks should be cloned for each branch');
+
+promise_test(async () => {
+
+  let pullCount = 0;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    pull(c) {
+      ++pullCount;
+      if (pullCount === 1) {
+        c.byobRequest.view[0] = 0x01;
+        c.byobRequest.respond(1);
+      }
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader();
+  const buffer = new Uint8Array([42, 42, 42]).buffer;
+
+  {
+    const result = await reader1.read(new Uint8Array(buffer, 0, 1));
+    assert_equals(result.done, false, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x01, 42, 42]).subarray(0, 1), 'value');
+  }
+
+  {
+    const result = await reader2.read();
+    assert_equals(result.done, false, 'done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x01]), 'value');
+  }
+
+}, 'ReadableStream teeing with byte source: chunks for BYOB requests from branch 1 should be cloned to branch 2');
+
+promise_test(async t => {
+
+  const theError = { name: 'boo!' };
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      c.enqueue(new Uint8Array([0x01]));
+      c.enqueue(new Uint8Array([0x02]));
+    },
+    pull() {
+      throw theError;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+
+  {
+    const result = await reader1.read(new Uint8Array(1));
+    assert_equals(result.done, false, 'first read from branch1 should not be done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x01]), 'first read from branch1');
+  }
+
+  {
+    const result = await reader1.read(new Uint8Array(1));
+    assert_equals(result.done, false, 'second read from branch1 should not be done');
+    assert_typed_array_equals(result.value, new Uint8Array([0x02]), 'second read from branch1');
+  }
+
+  await promise_rejects_exactly(t, theError, reader1.read(new Uint8Array(1)));
+  await promise_rejects_exactly(t, theError, reader2.read(new Uint8Array(1)));
+
+  await Promise.all([
+    promise_rejects_exactly(t, theError, reader1.closed),
+    promise_rejects_exactly(t, theError, reader2.closed)
+  ]);
+
+}, 'ReadableStream teeing with byte source: errors in the source should propagate to both branches');
+
+promise_test(async () => {
+
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      c.enqueue(new Uint8Array([0x01]));
+      c.enqueue(new Uint8Array([0x02]));
+      c.close();
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  branch1.cancel();
+
+  const [chunks1, chunks2] = await Promise.all([readableStreamToArray(branch1), readableStreamToArray(branch2)]);
+  assert_array_equals(chunks1, [], 'branch1 should have no chunks');
+  assert_equals(chunks2.length, 2, 'branch2 should have two chunks');
+  assert_typed_array_equals(chunks2[0], new Uint8Array([0x01]), 'first chunk from branch2');
+  assert_typed_array_equals(chunks2[1], new Uint8Array([0x02]), 'second chunk from branch2');
+
+}, 'ReadableStream teeing with byte source: canceling branch1 should not impact branch2');
+
+promise_test(async () => {
+
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      c.enqueue(new Uint8Array([0x01]));
+      c.enqueue(new Uint8Array([0x02]));
+      c.close();
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  branch2.cancel();
+
+  const [chunks1, chunks2] = await Promise.all([readableStreamToArray(branch1), readableStreamToArray(branch2)]);
+  assert_equals(chunks1.length, 2, 'branch1 should have two chunks');
+  assert_typed_array_equals(chunks1[0], new Uint8Array([0x01]), 'first chunk from branch1');
+  assert_typed_array_equals(chunks1[1], new Uint8Array([0x02]), 'second chunk from branch1');
+  assert_array_equals(chunks2, [], 'branch2 should have no chunks');
+
+}, 'ReadableStream teeing with byte source: canceling branch2 should not impact branch1');
+
+templatedRSTeeCancel('ReadableStream teeing with byte source', (extras) => {
+  return new ReadableStream({ type: 'bytes', ...extras });
+});
+
+promise_test(async () => {
+
+  let controller;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+
+  const promise = Promise.all([reader1.closed, reader2.closed]);
+
+  controller.close();
+
+  // The branches are created with HWM 0, so we need to read from at least one of them
+  // to observe the stream becoming closed.
+  const read1 = await reader1.read(new Uint8Array(1));
+  assert_equals(read1.done, true, 'first read from branch1 should be done');
+
+  await promise;
+
+}, 'ReadableStream teeing with byte source: closing the original should close the branches');
+
+promise_test(async t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+
+  const theError = { name: 'boo!' };
+  const promise = Promise.all([
+    promise_rejects_exactly(t, theError, reader1.closed),
+    promise_rejects_exactly(t, theError, reader2.closed)
+  ]);
+
+  controller.error(theError);
+  await promise;
+
+}, 'ReadableStream teeing with byte source: erroring the original should immediately error the branches');
+
+promise_test(async t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader();
+  const reader2 = branch2.getReader();
+
+  const theError = { name: 'boo!' };
+  const promise = Promise.all([
+    promise_rejects_exactly(t, theError, reader1.read()),
+    promise_rejects_exactly(t, theError, reader2.read())
+  ]);
+
+  controller.error(theError);
+  await promise;
+
+}, 'ReadableStream teeing with byte source: erroring the original should error pending reads from default reader');
+
+promise_test(async t => {
+
+  let controller;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+
+  const theError = { name: 'boo!' };
+  const promise = Promise.all([
+    promise_rejects_exactly(t, theError, reader1.read(new Uint8Array(1))),
+    promise_rejects_exactly(t, theError, reader2.read(new Uint8Array(1)))
+  ]);
+
+  controller.error(theError);
+  await promise;
+
+}, 'ReadableStream teeing with byte source: erroring the original should error pending reads from BYOB reader');
+
+promise_test(async () => {
+
+  let controller;
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+  const cancelPromise = reader2.cancel();
+
+  controller.enqueue(new Uint8Array([0x01]));
+
+  const read1 = await reader1.read(new Uint8Array(1));
+  assert_equals(read1.done, false, 'first read() from branch1 should not be done');
+  assert_typed_array_equals(read1.value, new Uint8Array([0x01]), 'first read() from branch1');
+
+  controller.close();
+
+  const read2 = await reader1.read(new Uint8Array(1));
+  assert_equals(read2.done, true, 'second read() from branch1 should be done');
+
+  await Promise.all([
+    reader1.closed,
+    cancelPromise
+  ]);
+
+}, 'ReadableStream teeing with byte source: canceling branch1 should finish when branch2 reads until end of stream');
+
+promise_test(async t => {
+
+  let controller;
+  const theError = { name: 'boo!' };
+  const rs = new ReadableStream({
+    type: 'bytes',
+    start(c) {
+      controller = c;
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader({ mode: 'byob' });
+  const cancelPromise = reader2.cancel();
+
+  controller.error(theError);
+
+  await Promise.all([
+    promise_rejects_exactly(t, theError, reader1.read(new Uint8Array(1))),
+    cancelPromise
+  ]);
+
+}, 'ReadableStream teeing with byte source: canceling branch1 should finish when original stream errors');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  // Create two branches, each with a HWM of 0. This should result in no chunks being pulled.
+  rs.tee();
+
+  await flushAsyncEvents();
+  assert_array_equals(rs.events, [], 'pull should not be called');
+
+}, 'ReadableStream teeing with byte source: should not pull any chunks if no branches are reading');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({
+    type: 'bytes',
+    pull(controller) {
+      controller.enqueue(new Uint8Array([0x01]));
+    }
+  });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+  await Promise.all([
+    reader1.read(new Uint8Array(1)),
+    reader2.read(new Uint8Array(1))
+  ]);
+  assert_array_equals(rs.events, ['pull'], 'pull should be called once');
+
+}, 'ReadableStream teeing with byte source: should only pull enough to fill the emptiest queue');
+
+promise_test(async t => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+  const theError = { name: 'boo!' };
+
+  rs.controller.error(theError);
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  await flushAsyncEvents();
+  assert_array_equals(rs.events, [], 'pull should not be called');
+
+  await Promise.all([
+    promise_rejects_exactly(t, theError, reader1.closed),
+    promise_rejects_exactly(t, theError, reader2.closed)
+  ]);
+
+}, 'ReadableStream teeing with byte source: should not pull when original is already errored');
+
+for (const branch of [1, 2]) {
+  promise_test(async t => {
+
+    const rs = recordingReadableStream({ type: 'bytes' });
+    const theError = { name: 'boo!' };
+
+    const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+    await flushAsyncEvents();
+    assert_array_equals(rs.events, [], 'pull should not be called');
+
+    const reader = (branch === 1) ? reader1 : reader2;
+    const read1 = reader.read(new Uint8Array(1));
+
+    await flushAsyncEvents();
+    assert_array_equals(rs.events, ['pull'], 'pull should be called once');
+
+    rs.controller.error(theError);
+
+    await Promise.all([
+      promise_rejects_exactly(t, theError, read1),
+      promise_rejects_exactly(t, theError, reader1.closed),
+      promise_rejects_exactly(t, theError, reader2.closed)
+    ]);
+
+    await flushAsyncEvents();
+    assert_array_equals(rs.events, ['pull'], 'pull should be called once');
+
+  }, `ReadableStream teeing with byte source: stops pulling when original stream errors while branch ${branch} is reading`);
+}
+
+promise_test(async t => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+  const theError = { name: 'boo!' };
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  await flushAsyncEvents();
+  assert_array_equals(rs.events, [], 'pull should not be called');
+
+  const read1 = reader1.read(new Uint8Array(1));
+  const read2 = reader2.read(new Uint8Array(1));
+
+  await flushAsyncEvents();
+  assert_array_equals(rs.events, ['pull'], 'pull should be called once');
+
+  rs.controller.error(theError);
+
+  await Promise.all([
+    promise_rejects_exactly(t, theError, read1),
+    promise_rejects_exactly(t, theError, read2),
+    promise_rejects_exactly(t, theError, reader1.closed),
+    promise_rejects_exactly(t, theError, reader2.closed)
+  ]);
+
+  await flushAsyncEvents();
+  assert_array_equals(rs.events, ['pull'], 'pull should be called once');
+
+}, 'ReadableStream teeing with byte source: stops pulling when original stream errors while both branches are reading');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  const read2 = reader2.read(new Uint8Array([0x22]));
+
+  const cancel1 = reader1.cancel();
+  await flushAsyncEvents();
+  const cancel2 = reader2.cancel();
+
+  const result1 = await read1;
+  assert_object_equals(result1, { value: undefined, done: true });
+  const result2 = await read2;
+  assert_object_equals(result2, { value: undefined, done: true });
+
+  await Promise.all([cancel1, cancel2]);
+
+}, 'ReadableStream teeing with byte source: canceling both branches in sequence with delay');
+
+promise_test(async t => {
+
+  const theError = { name: 'boo!' };
+  const rs = new ReadableStream({
+    type: 'bytes',
+    cancel() {
+      throw theError;
+    }
+  });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  const read2 = reader2.read(new Uint8Array([0x22]));
+
+  const cancel1 = reader1.cancel();
+  await flushAsyncEvents();
+  const cancel2 = reader2.cancel();
+
+  const result1 = await read1;
+  assert_object_equals(result1, { value: undefined, done: true });
+  const result2 = await read2;
+  assert_object_equals(result2, { value: undefined, done: true });
+
+  await Promise.all([
+    promise_rejects_exactly(t, theError, cancel1),
+    promise_rejects_exactly(t, theError, cancel2)
+  ]);
+
+}, 'ReadableStream teeing with byte source: failing to cancel when canceling both branches in sequence with delay');
+
+promise_test(async () => {
+
+  let cancelResolve;
+  const cancelCalled = new Promise((resolve) => {
+    cancelResolve = resolve;
+  });
+  const rs = recordingReadableStream({
+    type: 'bytes',
+    cancel() {
+      cancelResolve();
+    }
+  });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // We are reading into branch1's buffer.
+  const byobRequest1 = rs.controller.byobRequest;
+  assert_not_equals(byobRequest1, null);
+  assert_typed_array_equals(byobRequest1.view, new Uint8Array([0x11]), 'byobRequest1.view');
+
+  // Cancelling branch1 should not affect the BYOB request.
+  const cancel1 = reader1.cancel();
+  const result1 = await read1;
+  assert_equals(result1.done, true);
+  assert_equals(result1.value, undefined);
+  await flushAsyncEvents();
+  const byobRequest2 = rs.controller.byobRequest;
+  assert_typed_array_equals(byobRequest2.view, new Uint8Array([0x11]), 'byobRequest2.view');
+
+  // Cancelling branch1 should invalidate the BYOB request.
+  const cancel2 = reader2.cancel();
+  await cancelCalled;
+  const byobRequest3 = rs.controller.byobRequest;
+  assert_equals(byobRequest3, null);
+  const result2 = await read2;
+  assert_equals(result2.done, true);
+  assert_equals(result2.value, undefined);
+
+  await Promise.all([cancel1, cancel2]);
+
+}, 'ReadableStream teeing with byte source: read from branch1 and branch2, cancel branch1, cancel branch2');
+
+promise_test(async () => {
+
+  let cancelResolve;
+  const cancelCalled = new Promise((resolve) => {
+    cancelResolve = resolve;
+  });
+  const rs = recordingReadableStream({
+    type: 'bytes',
+    cancel() {
+      cancelResolve();
+    }
+  });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // We are reading into branch1's buffer.
+  const byobRequest1 = rs.controller.byobRequest;
+  assert_not_equals(byobRequest1, null);
+  assert_typed_array_equals(byobRequest1.view, new Uint8Array([0x11]), 'byobRequest1.view');
+
+  // Cancelling branch2 should not affect the BYOB request.
+  const cancel2 = reader2.cancel();
+  const result2 = await read2;
+  assert_equals(result2.done, true);
+  assert_equals(result2.value, undefined);
+  await flushAsyncEvents();
+  const byobRequest2 = rs.controller.byobRequest;
+  assert_typed_array_equals(byobRequest2.view, new Uint8Array([0x11]), 'byobRequest2.view');
+
+  // Cancelling branch1 should invalidate the BYOB request.
+  const cancel1 = reader1.cancel();
+  await cancelCalled;
+  const byobRequest3 = rs.controller.byobRequest;
+  assert_equals(byobRequest3, null);
+  const result1 = await read1;
+  assert_equals(result1.done, true);
+  assert_equals(result1.value, undefined);
+
+  await Promise.all([cancel1, cancel2]);
+
+}, 'ReadableStream teeing with byte source: read from branch1 and branch2, cancel branch2, cancel branch1');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // We are reading into branch1's buffer.
+  assert_typed_array_equals(rs.controller.byobRequest.view, new Uint8Array([0x11]), 'first byobRequest.view');
+
+  // Cancelling branch2 should not affect the BYOB request.
+  reader2.cancel();
+  const result2 = await read2;
+  assert_equals(result2.done, true);
+  assert_equals(result2.value, undefined);
+  await flushAsyncEvents();
+  assert_typed_array_equals(rs.controller.byobRequest.view, new Uint8Array([0x11]), 'second byobRequest.view');
+
+  // Respond to the BYOB request.
+  rs.controller.byobRequest.view[0] = 0x33;
+  rs.controller.byobRequest.respond(1);
+
+  // branch1 should receive the read chunk.
+  const result1 = await read1;
+  assert_equals(result1.done, false);
+  assert_typed_array_equals(result1.value, new Uint8Array([0x33]), 'first read() from branch1');
+
+}, 'ReadableStream teeing with byte source: read from branch1 and branch2, cancel branch2, enqueue to branch1');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // We are reading into branch1's buffer.
+  assert_typed_array_equals(rs.controller.byobRequest.view, new Uint8Array([0x11]), 'first byobRequest.view');
+
+  // Cancelling branch1 should not affect the BYOB request.
+  reader1.cancel();
+  const result1 = await read1;
+  assert_equals(result1.done, true);
+  assert_equals(result1.value, undefined);
+  await flushAsyncEvents();
+  assert_typed_array_equals(rs.controller.byobRequest.view, new Uint8Array([0x11]), 'second byobRequest.view');
+
+  // Respond to the BYOB request.
+  rs.controller.byobRequest.view[0] = 0x33;
+  rs.controller.byobRequest.respond(1);
+
+  // branch2 should receive the read chunk.
+  const result2 = await read2;
+  assert_equals(result2.done, false);
+  assert_typed_array_equals(result2.value, new Uint8Array([0x33]), 'first read() from branch2');
+
+}, 'ReadableStream teeing with byte source: read from branch1 and branch2, cancel branch1, respond to branch2');
+
+promise_test(async () => {
+
+  let pullCount = 0;
+  const byobRequestDefined = [];
+  const rs = new ReadableStream({
+    type: 'bytes',
+    pull(c) {
+      ++pullCount;
+      byobRequestDefined.push(c.byobRequest !== null);
+      c.enqueue(new Uint8Array([pullCount]));
+    }
+  });
+
+  const [branch1, _] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+
+  const result1 = await reader1.read(new Uint8Array([0x11]));
+  assert_equals(result1.done, false, 'first read should not be done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x1]), 'first read');
+  assert_equals(pullCount, 1, 'pull() should be called once');
+  assert_equals(byobRequestDefined[0], true, 'should have created a BYOB request for first read');
+
+  reader1.releaseLock();
+  const reader2 = branch1.getReader();
+
+  const result2 = await reader2.read();
+  assert_equals(result2.done, false, 'second read should not be done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x2]), 'second read');
+  assert_equals(pullCount, 2, 'pull() should be called twice');
+  assert_equals(byobRequestDefined[1], false, 'should not have created a BYOB request for second read');
+
+}, 'ReadableStream teeing with byte source: pull with BYOB reader, then pull with default reader');
+
+promise_test(async () => {
+
+  let pullCount = 0;
+  const byobRequestDefined = [];
+  const rs = new ReadableStream({
+    type: 'bytes',
+    pull(c) {
+      ++pullCount;
+      byobRequestDefined.push(c.byobRequest !== null);
+      c.enqueue(new Uint8Array([pullCount]));
+    }
+  });
+
+  const [branch1, _] = rs.tee();
+  const reader1 = branch1.getReader();
+
+  const result1 = await reader1.read();
+  assert_equals(result1.done, false, 'first read should not be done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x1]), 'first read');
+  assert_equals(pullCount, 1, 'pull() should be called once');
+  assert_equals(byobRequestDefined[0], false, 'should not have created a BYOB request for first read');
+
+  reader1.releaseLock();
+  const reader2 = branch1.getReader({ mode: 'byob' });
+
+  const result2 = await reader2.read(new Uint8Array([0x22]));
+  assert_equals(result2.done, false, 'second read should not be done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x2]), 'second read');
+  assert_equals(pullCount, 2, 'pull() should be called twice');
+  assert_equals(byobRequestDefined[1], true, 'should have created a BYOB request for second read');
+
+}, 'ReadableStream teeing with byte source: pull with default reader, then pull with BYOB reader');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({
+    type: 'bytes'
+  });
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+
+  // Wait for each branch's start() promise to resolve.
+  await flushAsyncEvents();
+
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+
+  // branch2 should provide the BYOB request.
+  const byobRequest = rs.controller.byobRequest;
+  assert_typed_array_equals(byobRequest.view, new Uint8Array([0x22]), 'first BYOB request');
+  byobRequest.view[0] = 0x01;
+  byobRequest.respond(1);
+
+  const result1 = await read1;
+  assert_equals(result1.done, false, 'first read should not be done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x1]), 'first read');
+
+  const result2 = await read2;
+  assert_equals(result2.done, false, 'second read should not be done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x1]), 'second read');
+
+}, 'ReadableStream teeing with byte source: read from branch2, then read from branch1');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader();
+  const reader2 = branch2.getReader({ mode: 'byob' });
+  await flushAsyncEvents();
+
+  const read1 = reader1.read();
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // There should be no BYOB request.
+  assert_equals(rs.controller.byobRequest, null, 'first BYOB request');
+
+  // Close the stream.
+  rs.controller.close();
+
+  const result1 = await read1;
+  assert_equals(result1.done, true, 'read from branch1 should be done');
+  assert_equals(result1.value, undefined, 'read from branch1');
+
+  // branch2 should get its buffer back.
+  const result2 = await read2;
+  assert_equals(result2.done, true, 'read from branch2 should be done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x22]).subarray(0, 0), 'read from branch2');
+
+}, 'ReadableStream teeing with byte source: read from branch1 with default reader, then close while branch2 has pending BYOB read');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+  const [branch1, branch2] = rs.tee();
+  const reader1 = branch1.getReader({ mode: 'byob' });
+  const reader2 = branch2.getReader();
+  await flushAsyncEvents();
+
+  const read2 = reader2.read();
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  await flushAsyncEvents();
+
+  // There should be no BYOB request.
+  assert_equals(rs.controller.byobRequest, null, 'first BYOB request');
+
+  // Close the stream.
+  rs.controller.close();
+
+  const result2 = await read2;
+  assert_equals(result2.done, true, 'read from branch2 should be done');
+  assert_equals(result2.value, undefined, 'read from branch2');
+
+  // branch1 should get its buffer back.
+  const result1 = await read1;
+  assert_equals(result1.done, true, 'read from branch1 should be done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x11]).subarray(0, 0), 'read from branch1');
+
+}, 'ReadableStream teeing with byte source: read from branch2 with default reader, then close while branch1 has pending BYOB read');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+  await flushAsyncEvents();
+
+  const read1 = reader1.read(new Uint8Array([0x11]));
+  const read2 = reader2.read(new Uint8Array([0x22]));
+  await flushAsyncEvents();
+
+  // branch1 should provide the BYOB request.
+  const byobRequest = rs.controller.byobRequest;
+  assert_typed_array_equals(byobRequest.view, new Uint8Array([0x11]), 'first BYOB request');
+
+  // Close the stream.
+  rs.controller.close();
+  byobRequest.respond(0);
+
+  // Both branches should get their buffers back.
+  const result1 = await read1;
+  assert_equals(result1.done, true, 'first read should be done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x11]).subarray(0, 0), 'first read');
+
+  const result2 = await read2;
+  assert_equals(result2.done, true, 'second read should be done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x22]).subarray(0, 0), 'second read');
+
+}, 'ReadableStream teeing with byte source: close when both branches have pending BYOB reads');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader());
+  const branch1Reads = [reader1.read(), reader1.read()];
+  const branch2Reads = [reader2.read(), reader2.read()];
+
+  await flushAsyncEvents();
+  rs.controller.enqueue(new Uint8Array([0x11]));
+  rs.controller.close();
+
+  const result1 = await branch1Reads[0];
+  assert_equals(result1.done, false, 'first read() from branch1 should be not done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x11]), 'first chunk from branch1 should be correct');
+  const result2 = await branch2Reads[0];
+  assert_equals(result2.done, false, 'first read() from branch2 should be not done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x11]), 'first chunk from branch2 should be correct');
+
+  assert_object_equals(await branch1Reads[1], { value: undefined, done: true }, 'second read() from branch1 should be done');
+  assert_object_equals(await branch2Reads[1], { value: undefined, done: true }, 'second read() from branch2 should be done');
+
+}, 'ReadableStream teeing with byte source: enqueue() and close() while both branches are pulling');
+
+promise_test(async () => {
+
+  const rs = recordingReadableStream({ type: 'bytes' });
+
+  const [reader1, reader2] = rs.tee().map(branch => branch.getReader({ mode: 'byob' }));
+  const branch1Reads = [reader1.read(new Uint8Array(1)), reader1.read(new Uint8Array(1))];
+  const branch2Reads = [reader2.read(new Uint8Array(1)), reader2.read(new Uint8Array(1))];
+
+  await flushAsyncEvents();
+  rs.controller.byobRequest.view[0] = 0x11;
+  rs.controller.byobRequest.respond(1);
+  rs.controller.close();
+
+  const result1 = await branch1Reads[0];
+  assert_equals(result1.done, false, 'first read() from branch1 should be not done');
+  assert_typed_array_equals(result1.value, new Uint8Array([0x11]), 'first chunk from branch1 should be correct');
+  const result2 = await branch2Reads[0];
+  assert_equals(result2.done, false, 'first read() from branch2 should be not done');
+  assert_typed_array_equals(result2.value, new Uint8Array([0x11]), 'first chunk from branch2 should be correct');
+
+  const result3 = await branch1Reads[1];
+  assert_equals(result3.done, true, 'second read() from branch1 should be done');
+  assert_typed_array_equals(result3.value, new Uint8Array([0]).subarray(0, 0), 'second chunk from branch1 should be correct');
+  const result4 = await branch2Reads[1];
+  assert_equals(result4.done, true, 'second read() from branch2 should be done');
+  assert_typed_array_equals(result4.value, new Uint8Array([0]).subarray(0, 0), 'second chunk from branch2 should be correct');
+
+}, 'ReadableStream teeing with byte source: respond() and close() while both branches are pulling');