streams/transferable/worker.html

<!DOCTYPE html>
<meta charset="utf-8">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/helpers.js"></script>
<script src="../resources/test-utils.js"></script>
<script>
'use strict';

promise_test(t => {
  const orig = createOriginalReadableStream();
  const w = new Worker('resources/receiving-worker.js');
  t.add_cleanup(() => {
    w.terminate();
  });
  const promise = new Promise((resolve, reject) => {
    checkTestResults(w).then(resolve, reject);
    w.onerror = () => reject('error in worker');
  });
  w.postMessage(orig, [orig]);
  assert_true(orig.locked, 'the original stream should be locked');
  return promise;
}, 'worker.postMessage should be able to transfer a ReadableStream');

promise_test(t => {
  const w = new Worker('resources/sending-worker.js');
  t.add_cleanup(() => {
    w.terminate();
  });
  return new Promise((resolve, reject) => {
    testMessageEvent(w).then(resolve, reject);
    w.onerror = () => reject('error in worker');
  });
}, 'postMessage in a worker should be able to transfer a ReadableStream');

promise_test(async t => {
  const w = new Worker('resources/echo-worker.js');
  let controller;
  const orig = new ReadableStream({
    start(c) {
      controller = c;
    }
  });
  const targetStream = await new Promise((resolve, reject) => {
    w.onmessage = evt => resolve(evt.data);
    w.onerror = () => reject('error in worker');
    w.postMessage(orig, [orig]);
  });
  const reader = targetStream.getReader();
  const reads = [];
  // Place a lot of chunks "in transit". This should increase the likelihood
  // that they is a chunk at each relevant step when the worker is terminated.
  for (let i = 0; i < 50; ++i) {
    await delay(0);
    controller.enqueue(i);
    const expected = i;
    reads.push(reader.read().then(({value, done}) => {
      assert_false(done, 'we should not be done');
      assert_equals(value, expected, 'value should match expectation');
    }));
  }
  w.terminate();
  for (let i = 50; i < 60; ++i) {
    controller.enqueue(i);
    reads.push(
      reader.read().then(t.unreached_func('read() should not resolve')));
    await delay(0);
  }
  // We don't expect every read() to complete, but we want to give them a chance
  // to reject if they're going to.
  return Promise.race([
    Promise.all(reads),
    flushAsyncEvents()
  ]);
}, 'terminating a worker should not error the stream');
</script>