chromium/third_party/blink/web_tests/http/tests/streams/chromium/simple-queue-full-node-shift.html

<!DOCTYPE html>
<meta charset="utf-8">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/simple-queue-common.js"></script>
<script>
promise_test(t => {
  let lastChunk;
  const ws = new WritableStream({
    write(chunk) {
      lastChunk = chunk;
    }
  });
  const writer = ws.getWriter();
  let lastPromise;
  // All chunks will be queued.
  for (let i = 0; i < QUEUE_MAX_ARRAY_SIZE; ++i) {
    lastPromise = writer.write(i);
  }
  assert_equals(undefined, lastChunk,
                'underlying sink write() should not have been called yet');
  return lastPromise.then(() => {
    assert_equals(QUEUE_MAX_ARRAY_SIZE - 1, lastChunk,
                  'lastChunk should equal QUEUE_MAX_ARRAY_SIZE - 1');
  });
}, 'shift() should work when exactly one full node exists');
</script>