webrtc/RTCPeerConnection-setRemoteDescription-offer.html

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<title>RTCPeerConnection.prototype.setRemoteDescription - offer</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="RTCPeerConnection-helper.js"></script>
<script>
  'use strict';

  // The following helper functions are called from RTCPeerConnection-helper.js:
  //   assert_session_desc_similar()
  //   generateAudioReceiveOnlyOffer

  /*
    4.3.2.  Interface Definition
      [Constructor(optional RTCConfiguration configuration)]
      interface RTCPeerConnection : EventTarget {
        Promise<void>                      setRemoteDescription(
            RTCSessionDescriptionInit description);

        readonly attribute RTCSessionDescription? remoteDescription;
        readonly attribute RTCSessionDescription? currentRemoteDescription;
        readonly attribute RTCSessionDescription? pendingRemoteDescription;
        ...
      };

    4.6.2.  RTCSessionDescription Class
      dictionary RTCSessionDescriptionInit {
        required RTCSdpType type;
                 DOMString  sdp = "";
      };

    4.6.1.  RTCSdpType
      enum RTCSdpType {
        "offer",
        "pranswer",
        "answer",
        "rollback"
      };
   */

  /*
    4.3.1.6.  Set the RTCSessionSessionDescription
      2.2.3.  Otherwise, if description is set as a remote description, then run one of
              the following steps:
        - If description is of type "offer", set connection.pendingRemoteDescription
          attribute to description and signaling state to have-remote-offer.
   */

  promise_test(t => {
    const pc1 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    pc1.createDataChannel('datachannel');

    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc2.close());

    const states = [];
    pc2.addEventListener('signalingstatechange', () => states.push(pc2.signalingState));

    return pc1.createOffer()
     .then(offer => {
      return pc2.setRemoteDescription(offer)
      .then(() => {
        assert_equals(pc2.signalingState, 'have-remote-offer');
        assert_session_desc_similar(pc2.remoteDescription, offer);
        assert_session_desc_similar(pc2.pendingRemoteDescription, offer);
        assert_equals(pc2.currentRemoteDescription, null);

        assert_array_equals(states, ['have-remote-offer']);
      });
    });
  }, 'setRemoteDescription with valid offer should succeed');

  promise_test(t => {
    const pc1 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    pc1.createDataChannel('datachannel');

    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc2.close());

    const states = [];
    pc2.addEventListener('signalingstatechange', () => states.push(pc2.signalingState));

    return pc1.createOffer()
    .then(offer => {
      return pc2.setRemoteDescription(offer)
      .then(() => pc2.setRemoteDescription(offer))
      .then(() => {
        assert_equals(pc2.signalingState, 'have-remote-offer');
        assert_session_desc_similar(pc2.remoteDescription, offer);
        assert_session_desc_similar(pc2.pendingRemoteDescription, offer);
        assert_equals(pc2.currentRemoteDescription, null);

        assert_array_equals(states, ['have-remote-offer']);
      });
    });
  }, 'setRemoteDescription multiple times should succeed');

  promise_test(t => {
    const pc1 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    pc1.createDataChannel('datachannel');

    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc2.close());

    const states = [];
    pc2.addEventListener('signalingstatechange', () => states.push(pc2.signalingState));

    return pc1.createOffer()
    .then(offer1 => {
      return pc1.setLocalDescription(offer1)
       .then(()=> {
        return generateAudioReceiveOnlyOffer(pc1)
        .then(offer2 => {
          assert_session_desc_not_similar(offer1, offer2);

          return pc2.setRemoteDescription(offer1)
          .then(() => pc2.setRemoteDescription(offer2))
          .then(() => {
            assert_equals(pc2.signalingState, 'have-remote-offer');
            assert_session_desc_similar(pc2.remoteDescription, offer2);
            assert_session_desc_similar(pc2.pendingRemoteDescription, offer2);
            assert_equals(pc2.currentRemoteDescription, null);

            assert_array_equals(states, ['have-remote-offer']);
          });
        });
      });
    });
  }, 'setRemoteDescription multiple times with different offer should succeed');

  /*
    4.3.1.6.  Set the RTCSessionSessionDescription
      2.1.4.  If the content of description is not valid SDP syntax, then reject p with
              an RTCError (with errorDetail set to "sdp-syntax-error" and the
              sdpLineNumber attribute set to the line number in the SDP where the syntax
              error was detected) and abort these steps.
   */
  promise_test(t => {
    const pc = new RTCPeerConnection();

    t.add_cleanup(() => pc.close());

    return pc.setRemoteDescription({
      type: 'offer',
      sdp: 'Invalid SDP'
    })
    .then(() => {
      assert_unreached('Expect promise to be rejected');
    }, err => {
      assert_equals(err.errorDetail, 'sdp-syntax-error',
        'Expect error detail field to set to sdp-syntax-error');

      assert_true(err instanceof RTCError,
        'Expect err to be instance of RTCError');
    });
  }, 'setRemoteDescription(offer) with invalid SDP should reject with RTCError');

  promise_test(async t => {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    await pc1.setLocalDescription(await pc1.createOffer());
    await pc1.setRemoteDescription(await pc2.createOffer());
    assert_equals(pc1.signalingState, 'have-remote-offer');
  }, 'setRemoteDescription(offer) from have-local-offer should roll back and succeed');

  promise_test(async t => {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    await pc1.setLocalDescription(await pc1.createOffer());
    const p = pc1.setRemoteDescription(await pc2.createOffer());
    await new Promise(r => pc1.onsignalingstatechange = r);
    assert_equals(pc1.signalingState, 'stable');
    assert_equals(pc1.pendingLocalDescription, null);
    assert_equals(pc1.pendingRemoteDescription, null);
    await new Promise(r => pc1.onsignalingstatechange = r);
    assert_equals(pc1.signalingState, 'have-remote-offer');
    assert_equals(pc1.pendingLocalDescription, null);
    assert_equals(pc1.pendingRemoteDescription.type, 'answer');
    await p;
  }, 'setRemoteDescription(offer) from have-local-offer fires signalingstatechange twice');

  promise_test(async t => {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    await pc1.setLocalDescription(await pc1.createOffer());
    const offer = await pc2.createOffer();
    const p1 = pc1.setLocalDescription({type: 'rollback'});
    await new Promise(r => pc1.onsignalingstatechange = r);
    assert_equals(pc1.signalingState, 'stable');
    const p2 = pc1.addIceCandidate();
    const p3 = pc1.setRemoteDescription(offer);
    await promise_rejects(t, 'InvalidStateError', p2);
    await p1;
    await p3;
    assert_equals(pc1.signalingState, 'have-remote-offer');
  }, 'Naive rollback approach is not glare-proof (control)');

  promise_test(async t => {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    await pc1.setLocalDescription(await pc1.createOffer());
    const p = pc1.setRemoteDescription(await pc2.createOffer());
    await new Promise(r => pc1.onsignalingstatechange = r);
    assert_equals(pc1.signalingState, 'stable');
    await pc1.addIceCandidate();
    await p;
    assert_equals(pc1.signalingState, 'have-remote-offer');
  }, 'setRemoteDescription(offer) from have-local-offer is glare-proof');

  promise_test(async t => {
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    await pc1.setLocalDescription(await pc1.createOffer());
    const p = pc1.setRemoteDescription({type: 'offer', sdp: 'Invalid SDP'});
    await new Promise(r => pc1.onsignalingstatechange = r);
    assert_equals(pc1.signalingState, 'stable');
    assert_equals(pc1.pendingLocalDescription, null);
    assert_equals(pc1.pendingRemoteDescription, null);
    await promise_rejects(t, 'RTCError', p);
  }, 'setRemoteDescription(invalidOffer) from have-local-offer does not undo rollback');
</script>