|  | <!doctype html> | 
|  | <meta charset=utf-8> | 
|  | <title>RTCPeerConnection.prototype.setRemoteDescription rollback</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: | 
|  | // generateOffer | 
|  | // assert_session_desc_equals | 
|  | // test_state_change_event | 
|  |  | 
|  | /* | 
|  | 4.3.2. Interface Definition | 
|  | [Constructor(optional RTCConfiguration configuration)] | 
|  | interface RTCPeerConnection : EventTarget { | 
|  | Promise<void> setLocalDescription( | 
|  | RTCSessionDescriptionInit description); | 
|  |  | 
|  | readonly attribute RTCSessionDescription? localDescription; | 
|  | readonly attribute RTCSessionDescription? currentLocalDescription; | 
|  | readonly attribute RTCSessionDescription? pendingLocalDescription; | 
|  |  | 
|  | 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 "rollback", then this is a rollback. | 
|  | Set connection.pendingRemoteDescription to null and signaling state to stable. | 
|  | */ | 
|  | promise_test(t => { | 
|  | const pc = new RTCPeerConnection(); | 
|  |  | 
|  | test_state_change_event(t, pc, ['have-remote-offer', 'stable']); | 
|  |  | 
|  | return generateOffer({ data: true }) | 
|  | .then(offer => pc.setRemoteDescription(offer)) | 
|  | .then(() => { | 
|  | assert_equals(pc.signalingState, 'have-remote-offer'); | 
|  | assert_not_equals(pc.remoteDescription, null); | 
|  | assert_not_equals(pc.pendingRemoteDescription, null); | 
|  | assert_equals(pc.currentRemoteDescription, null); | 
|  |  | 
|  | return pc.setRemoteDescription({ type: 'rollback' }); | 
|  | }) | 
|  | .then(() => { | 
|  | assert_equals(pc.signalingState, 'stable'); | 
|  | assert_equals(pc.remoteDescription, null); | 
|  | assert_equals(pc.pendingRemoteDescription, null); | 
|  | assert_equals(pc.currentRemoteDescription, null); | 
|  | }); | 
|  | }, 'setRemoteDescription(rollback) in have-remote-offer state should revert to stable state'); | 
|  |  | 
|  | /* | 
|  | 4.3.1.6. Set the RTCSessionSessionDescription | 
|  | 2.3. If the description's type is invalid for the current signaling state of | 
|  | connection, then reject p with a newly created InvalidStateError and abort | 
|  | these steps. | 
|  |  | 
|  | [jsep] | 
|  | 4.1.8.2. Rollback | 
|  | - Rollback can only be used to cancel proposed changes; | 
|  | there is no support for rolling back from a stable state to a | 
|  | previous stable state | 
|  | */ | 
|  | promise_test(t => { | 
|  | const pc = new RTCPeerConnection(); | 
|  | return promise_rejects(t, 'InvalidStateError', | 
|  | pc.setRemoteDescription({ type: 'rollback' })); | 
|  | }, `setRemoteDescription(rollback) from stable state should reject with InvalidStateError`); | 
|  |  | 
|  | promise_test(t => { | 
|  | const pc = new RTCPeerConnection(); | 
|  | return pc.createOffer({ offerToReceiveAudio: true }) | 
|  | .then(offer => pc.setRemoteDescription(offer)) | 
|  | .then(() => pc.setRemoteDescription({ | 
|  | type: 'rollback', | 
|  | sdp: '!<Invalid SDP Content>;' | 
|  | })); | 
|  | }, `setRemoteDescription(rollback) should ignore invalid sdp content and succeed`); | 
|  |  | 
|  | </script> |