scheduler/tentative/yield/yield-scripted-subframe-propagation.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
  async function getResultsInOrder(promises) {
    const results = [];
    const tasks = promises.map(p => p.then(r => results.push(r)));
    await Promise.all(tasks);
    return results;
  }

  promise_test(async t => {
    await new Promise(resolve => window.onload = resolve);
    const iframe = document.createElement('iframe');
    iframe.srcdoc = `
      <script>
        window.task = async function() {
          await scheduler.yield();
          return "inner";
        }

        window.task2 = async function(callback) {
          Promise.resolve().then(callback);
        }
      </scr`+`ipt>
    `;

    window.parentTask = async function() {
      await scheduler.yield();
      return "inner";
    };

    const p = new Promise(resolve => iframe.onload = resolve);
    document.body.appendChild(iframe);
    await p;

    // task1: user-blocking, main frame scheduler, child frame task.
    //   task 1 continuation: child frame yield().
    // task2: user-blocking, main frame scheduler, main frame task.
    //
    // Expected: no inheritance, task1 continuation has default continuation
    // priority and runs last.
    let task1 = scheduler.postTask(
        iframe.contentWindow.task, {priority: 'user-blocking'});
    let task2 = scheduler.postTask(() => "outer", {priority: 'user-blocking'});
    let result = await getResultsInOrder([task1, task2]);
    assert_equals(result.toString(), "outer,inner",
        "Expected outer before inner for iframe task with main frame scheduler");

    // task1: user-blocking, child frame scheduler, child frame task.
    //   task 1 continuation: child frame yield().
    // task2: user-blocking, main frame scheduler, main frame task.
    //
    // Expected: continuation inherits user-blocking priority and runs before
    // task2.
    task1 = iframe.contentWindow.scheduler.postTask(
        iframe.contentWindow.task, {priority: 'user-blocking'});
    task2 = scheduler.postTask(() => "outer", {priority: 'user-blocking'});
    result = await getResultsInOrder([task1, task2]);
    assert_equals(result.toString(), "inner,outer",
        "Expected inner before outer for iframe task with iframe scheduler");

    // task1: user-blocking, main frame scheduler, main frame task.
    //   task 1 continuation: child frame yield() called from main frame task.
    // task2: user-blocking, main frame scheduler, main frame task.
    //
    // Expected: no inheritance, task1 continuation has default continuation
    // priority and runs last.
    task1 = scheduler.postTask(
        async () => await iframe.contentWindow.task(), {priority: 'user-blocking'});
    task2 = scheduler.postTask(() => "outer", {priority: 'user-blocking'});
    result = await getResultsInOrder([task1, task2]);
    assert_equals(result.toString(), "outer,inner",
        "Expected outer before inner for iframe task called from main frame task");

    // This tests that priority is inherited in the main frame if hopping
    // through a child frame task.
    //
    // task1: user-blocking; main frame scheduler; main frame task, which calls
    //        back into the main frame in a microtask.
    //   task 1 continuation: main frame yield, called from child frame.
    // task2: user-blocking, main frame scheduler, main frame task.
    //
    // Expected: continuation inherits user-blocking priority and runs before
    // task2.
    task1 = scheduler.postTask(() => new Promise(resolve => {
      iframe.contentWindow.task2(async () => {
        await scheduler.yield();
        resolve("inner");
      });
    }), {priority: 'user-blocking'});
    task2 = scheduler.postTask(() => "outer", {priority: 'user-blocking'});
    result = await getResultsInOrder([task1, task2]);
    assert_equals(result.toString(), "inner,outer",
        "Expected inner before outer for iframe task calling back to main frame task");
  }, 'Test scheduler.yield() does not use propagated state in same origin frames');
</script>