webrtc/RTCPeerConnection-addTransceiver-renegotiation.https.html

<!doctype html>
<meta charset=utf-8>
<title>RTCPeerConnection: media flows to a second unidirectional transceiver added through renegotiation.</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="RTCPeerConnection-helper.js"></script>
<script>
  'use strict';

  async function doTest(t, kind, firstTransceiverDirection) {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());

    exchangeIceCandidates(pc1, pc2);

    // Add a transceiver that we won't use and negotiate.
    pc1.addTransceiver(kind, {direction: "recvonly"});
    await pc1.setLocalDescription();
    await pc2.setRemoteDescription(pc1.localDescription);
    const [sendTransceiver1] = pc2.getTransceivers();
    sendTransceiver1.direction = firstTransceiverDirection;
    await pc2.setLocalDescription();
    await pc1.setRemoteDescription(pc2.localDescription);

    // Add another transceiver, that we will use, and renegotiate.
    const stream = await getNoiseStream({[kind]: true});
    const [track] = stream.getTracks();
    t.add_cleanup(() => track.stop());

    pc1.addTransceiver(kind, {direction: "recvonly"});
    await pc1.setLocalDescription();
    await pc2.setRemoteDescription(pc1.localDescription);
    const [, sendTransceiver2] = pc2.getTransceivers();
    sendTransceiver2.direction = "sendonly";
    sendTransceiver2.sender.replaceTrack(track);

    await pc2.setLocalDescription();
    await pc1.setRemoteDescription(pc2.localDescription);

    const [, recvTransceiver] = pc1.getTransceivers();
    const {receiver} = recvTransceiver;
    const threshold = 10;
    let inboundStats, timedout = false;
    t.step_timeout(() => timedout = true, 2000);
    while (!timedout) {
      const stats = await receiver.getStats();
      inboundStats = [...stats.values()].find(({type}) => type == "inbound-rtp");
      if (inboundStats?.packetsReceived > threshold) break;
      await new Promise(r => t.step_timeout(r, 50));
    }
    assert_greater_than(inboundStats?.packetsReceived,
      threshold,
      "packets received indicates media flow."
    );
  }

  promise_test(async t => {
    await doTest(t, "video", "sendonly");
  }, "Video flows to RTCPeerConnection's second transceiver added through renegotiation, with first transceiver also sending");

  promise_test(async t => {
    await doTest(t, "audio", "sendonly");
  }, "Audio flows to RTCPeerConnection's second transceiver added through renegotiation, with first transceiver also sending");

  promise_test(async t => {
    await doTest(t, "video", "inactive");
  }, "Video flows to RTCPeerConnection's second transceiver added through renegotiation, with first transceiver inactive");

  promise_test(async t => {
    await doTest(t, "audio", "inactive");
  }, "Audio flows to RTCPeerConnection's second transceiver added through renegotiation, with first transceiver inactive");

</script>