<!DOCTYPE HTML>
<meta charset="utf-8">
<title>Test for bug 1639328</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" href="/tests/SimpleTest/test.css">
<style>
  /* To ensure that they're all in the viewport when displayed */
  iframe {
    width: 10px;
    height: 10px;
  }
</style>
<iframe id="http" src="https://example.com/tests/dom/base/test/file_bug1639328.html"></iframe>
<iframe id="https" src="https://example.com/tests/dom/base/test/file_bug1639328.html"></iframe>
<iframe id="same-origin" src="file_bug1639328.html"></iframe>
<iframe id="display-none-http" style="display: none" src="https://example.com/tests/dom/base/test/file_bug1639328.html"></iframe>
<iframe id="display-none-https" style="display: none" src="https://example.com/tests/dom/base/test/file_bug1639328.html"></iframe>
<iframe id="display-none-same-origin" style="display: none" src="file_bug1639328.html"></iframe>
<script>
SimpleTest.waitForExplicitFinish();

function getOneMessage(frame) {
  info(`querying ${frame.src} (${frame.id})`);
  let resolve;
  let promise = new Promise(r => { resolve = r; });
  window.addEventListener("message", function(e) {
    info("got " + JSON.stringify(e.data));
    resolve(e.data);
  }, { once: true });
  frame.contentWindow.postMessage("ping", "*");
  return promise;
}

async function ticks(n) {
  for (let i = 0; i < n; ++i) {
    await new Promise(resolve => requestAnimationFrame(resolve));
  }
}

async function checkFrame(frame, shouldThrottle) {
  let message = null;
  do {
    if (message) {
      await ticks(2);
    }
    message = await getOneMessage(frame);
  } while (message.throttledFrameRequests != shouldThrottle);
  is(message.throttledFrameRequests, shouldThrottle, frame.id);
}

onload = async function() {
  await SimpleTest.promiseFocus(window);
  await ticks(2);
  is(SpecialPowers.DOMWindowUtils.effectivelyThrottlesFrameRequests, false, "Should not be throttling main page");
  for (let frame of document.querySelectorAll("iframe")) {
    let shouldThrottle = frame.style.display == "none";
    await checkFrame(frame, shouldThrottle);
    info("Switching display of " + frame.id);
    frame.style.display = shouldThrottle ? "" : "none";
    await checkFrame(frame, !shouldThrottle);
    info("And switching display back for " + frame.id);
    frame.style.display = shouldThrottle ? "none" : "";
    await checkFrame(frame, shouldThrottle);
  }

  SimpleTest.finish();
};
</script>
