<!doctype html>
<meta charset=utf-8>
<title>RTCDataChannel id attribute</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
'use strict';

// This and the test below verify that after a description is set that
// negotiates the DTLS role used by SCTP, data channels with unset IDs
// have IDs set according to the rules in rtcweb-data-channel.
promise_test(test => {
  const pc = new RTCPeerConnection;
  test.add_cleanup(() => pc.close());
  const channel = pc.createDataChannel('');
  return pc.createOffer()
  .then(offer => pc.setLocalDescription(offer))
  .then(() => {
    // Turn our own offer SDP into valid answer SDP by setting the DTLS role to
    // "active".
    const answer = {
      type: "answer",
      sdp: pc.localDescription.sdp.replace("actpass", "active")
    };
    return pc.setRemoteDescription(answer);
  })
  .then(() => {
    // Since the remote description had an "active" DTLS role, we're the server
    // and should use odd data channel IDs, according to rtcweb-data-channel.
    assert_equals(channel.id % 2, 1, 'id');
    const another_channel = pc.createDataChannel('another');
    assert_equals(another_channel.id % 2, 1, 'id');
    assert_not_equals(channel.id, another_channel.id);
  })
}, "DTLS client uses odd data channel IDs");

promise_test(test => {
  const pc = new RTCPeerConnection;
  test.add_cleanup(() => pc.close());
  const channel = pc.createDataChannel('');
  return pc.createOffer()
  .then(offer => pc.setLocalDescription(offer))
  .then(() => {
    // Turn our own offer SDP into valid answer SDP by setting the DTLS role to
    // "passive".
    const answer = {
      type: "answer",
      sdp: pc.localDescription.sdp.replace("actpass", "passive")
    };
    return pc.setRemoteDescription(answer);
  })
  .then(() => {
    // Since the remote description had a "passive" DTLS role, we're the client
    // and should use even data channel IDs, according to rtcweb-data-channel.
    assert_equals(channel.id % 2, 0, 'id');
    const another_channel = pc.createDataChannel('another');
    assert_equals(another_channel.id % 2, 0, 'id');
    assert_not_equals(channel.id, another_channel.id);
  })
}, "DTLS server uses even data channel IDs");

</script>