chromium/third_party/blink/web_tests/external/wpt/webrtc/simulcast/rid-manipulation.html

<!DOCTYPE html>
<meta charset=utf-8>
<title>RTCPeerConnection Simulcast Tests - RID manipulation</title>
<meta name="timeout" content="long">
<script src="../third_party/sdp/sdp.js"></script>
<script src="simulcast.js"></script>
<script src="../RTCPeerConnection-helper.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="../../mediacapture-streams/permission-helper.js"></script>
<script>

promise_test(async t => {
  const pc1 = new RTCPeerConnection();
  const pc2 = new RTCPeerConnection();
  t.add_cleanup(() => pc1.close());
  t.add_cleanup(() => pc2.close());
  const rids = [0, 1, 2];
  pc1.addTransceiver("video", {sendEncodings: rids.map(rid => ({rid}))});
  const [{sender}] = pc1.getTransceivers();

  const negotiateSfuAnswer = async asimulcast => {
    const offer = await pc1.createOffer();
    await pc1.setLocalDescription(offer);
    offer.sdp = swapRidAndMidExtensionsInSimulcastOffer(offer, rids);
    await pc2.setRemoteDescription(offer);
    const answer = await pc2.createAnswer();
    await pc2.setLocalDescription(answer);
    answer.sdp = swapRidAndMidExtensionsInSimulcastAnswer(answer,pc1.localDescription, rids);
    answer.sdp = answer.sdp.replace('a=simulcast:recv 0;1;2', asimulcast);
    return answer;
  };
  await pc1.setRemoteDescription(await negotiateSfuAnswer('a=simulcast:recv foo;1;2'));
  await pc1.setRemoteDescription(await negotiateSfuAnswer('a=simulcast:recv foo;bar;2'));
}, 'Remote reanswer altering rids does not throw an exception.');

</script>