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

  // Test is based on the following editor draft:
  // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.html

  // The following helper functions are called from RTCPeerConnection-helper.js:
  // exchangeIceCandidates
  // doSignalingHandshake

  /*
    6.2.  RTCDataChannel
      When an underlying data transport is to be announced
        2.  Let channel be a newly created RTCDataChannel object.
        5.  Set channel's readyState attribute to connecting.
        6.  Fire a datachannel event named datachannel with channel at the
            RTCPeerConnection object.

    6.3.  RTCDataChannelEvent
      Firing a datachannel event named e with a RTCDataChannel channel means
      that an event with the name e, which does not bubble (except where
      otherwise stated) and is not cancelable (except where otherwise stated),
      and which uses the RTCDataChannelEvent interface with the channel
      attribute set to channel, must be created and dispatched at the given
      target.

      interface RTCDataChannelEvent : Event {
        readonly attribute RTCDataChannel channel;
      };
   */
  async_test(t => {
    const localPc = new RTCPeerConnection();
    t.add_cleanup(() => localPc.close());
    const remotePc = new RTCPeerConnection();

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

    let eventCount = 0;

    const onDataChannel = t.step_func_done(event => {
      eventCount++;
      assert_equals(eventCount, 1,
        'Expect data channel event to fire exactly once');

      assert_true(event instanceof RTCDataChannelEvent,
        'Expect event to be instance of RTCDataChannelEvent');

      assert_equals(event.bubbles, false);
      assert_equals(event.cancelable, false);

      const { channel } = event;
      assert_true(channel instanceof RTCDataChannel,
        'Expect channel to be instance of RTCDataChannel');

      const { readyState } = channel;

      // The spec requires readyState to be connecting at first,
      // but it may quickly change to open before the callback
      // is invoked, especially with local connections.
      assert_true(readyState === 'connecting' || readyState === 'open',
        'Expect channel ready state to be either connecting or open');
    });

    localPc.createDataChannel('test');

    remotePc.addEventListener('datachannel', onDataChannel);
    exchangeIceCandidates(localPc, remotePc);
    doSignalingHandshake(localPc, remotePc);
  }, 'datachannel event should fire when new data channel is announced to the remote peer');

  /*
    6.2.  RTCDataChannel
      interface RTCDataChannel : EventTarget {
        readonly attribute USVString           label;
        readonly attribute boolean             ordered;
        readonly attribute unsigned short?     maxPacketLifeTime;
        readonly attribute unsigned short?     maxRetransmits;
        readonly attribute USVString           protocol;
        readonly attribute boolean             negotiated;
        readonly attribute unsigned short?     id;
        readonly attribute RTCPriorityType     priority;
        readonly attribute RTCDataChannelState readyState;
        ...
      };

      When an underlying data transport is to be announced
        3.  Let configuration be an information bundle received from the
            other peer as a part of the process to establish the underlying
            data transport described by the WebRTC DataChannel Protocol
            specification [RTCWEB-DATA-PROTOCOL].
        4.  Initialize channel's label, ordered, maxPacketLifeTime,
            maxRetransmits, protocol, negotiated and id attributes to their
            corresponding values in configuration.
   */
  async_test(t => {
    const localPc = new RTCPeerConnection();
    t.add_cleanup(() => localPc.close());
    const remotePc = new RTCPeerConnection();

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

    const onDataChannel = t.step_func_done(event => {
      const remoteChannel = event.channel;
      assert_true(remoteChannel instanceof RTCDataChannel,
        'Expect channel to be instance of RTCDataChannel');

      assert_equals(remoteChannel.label, 'test');
      assert_equals(remoteChannel.id, 8);
      assert_equals(remoteChannel.ordered, false);
      assert_equals(remoteChannel.maxRetransmits, 1);
      assert_equals(remoteChannel.protocol, 'custom');
      assert_equals(remoteChannel.priority, 'high');
    });

    const localChannel = localPc.createDataChannel('test', {
      id: 8,
      ordered: false,
      maxRetransmits: 1,
      protocol: 'custom',
      priority: 'high'
    });

    assert_equals(localChannel.label, 'test');
    assert_equals(localChannel.id, 8);
    assert_equals(localChannel.ordered, false);
    assert_equals(localChannel.maxRetransmits, 1);
    assert_equals(localChannel.protocol, 'custom');
    assert_equals(localChannel.priority, 'high');

    remotePc.addEventListener('datachannel', onDataChannel);
    exchangeIceCandidates(localPc, remotePc);
    doSignalingHandshake(localPc, remotePc);
  }, 'Data channel created on remote peer should match the same configuration as local peer');

  /*
    6.2.  RTCDataChannel
      Dictionary RTCDataChannelInit Members
        negotiated
          The default value of false tells the user agent to announce the
          channel in-band and instruct the other peer to dispatch a corresponding
          RTCDataChannel object. If set to true, it is up to the application
          to negotiate the channel and create a RTCDataChannel object with the
          same id at the other peer.
   */
  async_test(t => {
    const localPc = new RTCPeerConnection();
    t.add_cleanup(() => localPc.close());
    const remotePc = new RTCPeerConnection();

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

    const onDataChannel = t.unreached_func('datachannel event should not be fired');

    localPc.createDataChannel('test', {
      negotiated: true
    });

    remotePc.addEventListener('datachannel', onDataChannel);
    exchangeIceCandidates(localPc, remotePc);
    doSignalingHandshake(localPc, remotePc);

    t.step_timeout(t.step_func_done(), 200);
  }, 'Data channel created with negotiated set to true should not fire datachannel event on remote peer');

  /*
    Non-testable
    6.2.  RTCDataChannel
      When an underlying data transport is to be announced
        1.  If the associated RTCPeerConnection object's [[isClosed]] slot
            is true, abort these steps.

    The above step is not testable because to reach it we would have to
    close the peer connection after the remote peer call
    setLocalDescription(answer) but before the underlying data transport
    is connected. This require the promise callback for setLocalDescription()
    to be called at the right moment, which is not always possible.
   */
</script>