'use strict'
/*
* Taken from wpt/webrtc/RTCPeerConnection-helper.js, update occasionally.
*
* Helper Methods for testing the following methods in RTCPeerConnection:
* createOffer
* createAnswer
* setLocalDescription
* setRemoteDescription
*
* This file offers the following features:
* SDP similarity comparison
* Generating offer/answer using anonymous peer connection
* Test signalingstatechange event
* Test promise that never resolve
*/
const audioLineRegex = /\r\nm=audio.+\r\n/g;
const videoLineRegex = /\r\nm=video.+\r\n/g;
const applicationLineRegex = /\r\nm=application.+\r\n/g;
function countLine(sdp, regex) {
const matches = sdp.match(regex);
if(matches === null) {
return 0;
} else {
return matches.length;
}
}
function countAudioLine(sdp) {
return countLine(sdp, audioLineRegex);
}
function countVideoLine(sdp) {
return countLine(sdp, videoLineRegex);
}
function countApplicationLine(sdp) {
return countLine(sdp, applicationLineRegex);
}
function similarMediaDescriptions(sdp1, sdp2) {
if(sdp1 === sdp2) {
return true;
} else if(
countAudioLine(sdp1) !== countAudioLine(sdp2) ||
countVideoLine(sdp1) !== countVideoLine(sdp2) ||
countApplicationLine(sdp1) !== countApplicationLine(sdp2))
{
return false;
} else {
return true;
}
}
// Assert that given object is either an
// RTCSessionDescription or RTCSessionDescriptionInit
function assert_is_session_description(sessionDesc) {
if(sessionDesc instanceof RTCSessionDescription) {
return;
}
assert_not_equals(sessionDesc, undefined,
'Expect session description to be defined');
assert_true(typeof(sessionDesc) === 'object',
'Expect sessionDescription to be either a RTCSessionDescription or an object');
assert_true(typeof(sessionDesc.type) === 'string',
'Expect sessionDescription.type to be a string');
assert_true(typeof(sessionDesc.sdp) === 'string',
'Expect sessionDescription.sdp to be a string');
}
// We can't do string comparison to the SDP content,
// because RTCPeerConnection may return SDP that is
// slightly modified or reordered from what is given
// to it due to ICE candidate events or serialization.
// Instead, we create SDP with different number of media
// lines, and if the SDP strings are not the same, we
// simply count the media description lines and if they
// are the same, we assume it is the same.
function isSimilarSessionDescription(sessionDesc1, sessionDesc2) {
assert_is_session_description(sessionDesc1);
assert_is_session_description(sessionDesc2);
if(sessionDesc1.type !== sessionDesc2.type) {
return false;
} else {
return similarMediaDescriptions(sessionDesc1.sdp, sessionDesc2.sdp);
}
}
function assert_session_desc_similar(sessionDesc1, sessionDesc2) {
assert_true(isSimilarSessionDescription(sessionDesc1, sessionDesc2),
'Expect both session descriptions to have the same count of media lines');
}
function assert_session_desc_not_similar(sessionDesc1, sessionDesc2) {
assert_false(isSimilarSessionDescription(sessionDesc1, sessionDesc2),
'Expect both session descriptions to have different count of media lines');
}
async function generateDataChannelOffer(pc) {
pc.createDataChannel('test');
const offer = await pc.createOffer();
assert_equals(countApplicationLine(offer.sdp), 1, 'Expect m=application line to be present in generated SDP');
return offer;
}
async function generateAudioReceiveOnlyOffer(pc)
{
try {
pc.addTransceiver('audio', { direction: 'recvonly' });
return pc.createOffer();
} catch(e) {
return pc.createOffer({ offerToReceiveAudio: true });
}
}
async function generateVideoReceiveOnlyOffer(pc)
{
try {
pc.addTransceiver('video', { direction: 'recvonly' });
return pc.createOffer();
} catch(e) {
return pc.createOffer({ offerToReceiveVideo: true });
}
}
// Helper function to generate answer based on given offer using a freshly
// created RTCPeerConnection object
async function generateAnswer(offer) {
const pc = new RTCPeerConnection();
await pc.setRemoteDescription(offer);
const answer = await pc.createAnswer();
pc.close();
return answer;
}
// Helper function to generate offer using a freshly
// created RTCPeerConnection object
async function generateOffer() {
const pc = new RTCPeerConnection();
const offer = await pc.createOffer();
pc.close();
return offer;
}
// Run a test function that return a promise that should
// never be resolved. For lack of better options,
// we wait for a time out and pass the test if the
// promise doesn't resolve within that time.
function test_never_resolve(testFunc, testName) {
async_test(t => {
testFunc(t)
.then(
t.step_func(result => {
assert_unreached(`Pending promise should never be resolved. Instead it is fulfilled with: ${result}`);
}),
t.step_func(err => {
assert_unreached(`Pending promise should never be resolved. Instead it is rejected with: ${err}`);
}));
t.step_timeout(t.step_func_done(), 100)
}, testName);
}
// Helper function to exchange ice candidates between
// two local peer connections
function exchangeIceCandidates(pc1, pc2) {
// private function
function doExchange(localPc, remotePc) {
localPc.addEventListener('icecandidate', event => {
const { candidate } = event;
// Guard against already closed peerconnection to
// avoid unrelated exceptions.
if (remotePc.signalingState !== 'closed') {
remotePc.addIceCandidate(candidate);
}
});
}
doExchange(pc1, pc2);
doExchange(pc2, pc1);
}
// Returns a promise that resolves when a |name| event is fired.
function waitUntilEvent(obj, name) {
return new Promise(r => obj.addEventListener(name, r, {once: true}));
}
// Returns a promise that resolves when the |transport.state| is |state|
// This should work for RTCSctpTransport, RTCDtlsTransport and RTCIceTransport.
async function waitForState(transport, state) {
while (transport.state != state) {
await waitUntilEvent(transport, 'statechange');
}
}
// Returns a promise that resolves when |pc.iceConnectionState| is 'connected'
// or 'completed'.
async function listenToIceConnected(pc) {
await waitForIceStateChange(pc, ['connected', 'completed']);
}
// Returns a promise that resolves when |pc.iceConnectionState| is in one of the
// wanted states.
async function waitForIceStateChange(pc, wantedStates) {
while (!wantedStates.includes(pc.iceConnectionState)) {
await waitUntilEvent(pc, 'iceconnectionstatechange');
}
}
// Returns a promise that resolves when |pc.connectionState| is 'connected'.
async function listenToConnected(pc) {
while (pc.connectionState != 'connected') {
await waitUntilEvent(pc, 'connectionstatechange');
}
}
// Returns a promise that resolves when |pc.connectionState| is in one of the
// wanted states.
async function waitForConnectionStateChange(pc, wantedStates) {
while (!wantedStates.includes(pc.connectionState)) {
await waitUntilEvent(pc, 'connectionstatechange');
}
}
async function waitForIceGatheringState(pc, wantedStates) {
while (!wantedStates.includes(pc.iceGatheringState)) {
await waitUntilEvent(pc, 'icegatheringstatechange');
}
}
// Resolves when RTP packets have been received.
async function listenForSSRCs(t, receiver) {
while (true) {
const ssrcs = receiver.getSynchronizationSources();
if (Array.isArray(ssrcs) && ssrcs.length > 0) {
return ssrcs;
}
await new Promise(r => t.step_timeout(r, 0));
}
}
// Helper function to create a pair of connected data channels.
// On success the promise resolves to an array with two data channels.
// It does the heavy lifting of performing signaling handshake,
// ICE candidate exchange, and waiting for data channel at two
// end points to open. Can do both negotiated and non-negotiated setup.
async function createDataChannelPair(t, options,
pc1 = createPeerConnectionWithCleanup(t),
pc2 = createPeerConnectionWithCleanup(t)) {
let pair = [], bothOpen;
try {
if (options.negotiated) {
pair = [pc1, pc2].map(pc => pc.createDataChannel('', options));
bothOpen = Promise.all(pair.map(dc => new Promise((r, e) => {
dc.onopen = r;
dc.onerror = ({error}) => e(error);
})));
} else {
pair = [pc1.createDataChannel('', options)];
bothOpen = Promise.all([
new Promise((r, e) => {
pair[0].onopen = r;
pair[0].onerror = ({error}) => e(error);
}),
new Promise((r, e) => pc2.ondatachannel = ({channel}) => {
pair[1] = channel;
channel.onopen = r;
channel.onerror = ({error}) => e(error);
})
]);
}
exchangeIceCandidates(pc1, pc2);
await exchangeOfferAnswer(pc1, pc2);
await bothOpen;
return pair;
} finally {
for (const dc of pair) {
dc.onopen = dc.onerror = null;
}
}
}
// Wait for RTP and RTCP stats to arrive
async function waitForRtpAndRtcpStats(pc) {
// If remote stats are never reported, return after 5 seconds.
const startTime = performance.now();
while (true) {
const report = await pc.getStats();
const stats = [...report.values()].filter(({type}) => type.endsWith("bound-rtp"));
// Each RTP and RTCP stat has a reference
// to the matching stat in the other direction
if (stats.length && stats.every(({localId, remoteId}) => localId || remoteId)) {
break;
}
if (performance.now() > startTime + 5000) {
break;
}
}
}
// Wait for a single message event and return
// a promise that resolve when the event fires
function awaitMessage(channel) {
const once = true;
return new Promise((resolve, reject) => {
channel.addEventListener('message', ({data}) => resolve(data), {once});
channel.addEventListener('error', reject, {once});
});
}
// Helper to convert a blob to array buffer so that
// we can read the content
async function blobToArrayBuffer(blob) {
const reader = new FileReader();
reader.readAsArrayBuffer(blob);
return new Promise((resolve, reject) => {
reader.addEventListener('load', () => resolve(reader.result), {once: true});
reader.addEventListener('error', () => reject(reader.error), {once: true});
});
}
// Assert that two TypedArray or ArrayBuffer objects have the same byte values
function assert_equals_typed_array(array1, array2) {
const [view1, view2] = [array1, array2].map((array) => {
if (array instanceof ArrayBuffer) {
return new DataView(array);
} else {
assert_true(array.buffer instanceof ArrayBuffer,
'Expect buffer to be instance of ArrayBuffer');
return new DataView(array.buffer, array.byteOffset, array.byteLength);
}
});
assert_equals(view1.byteLength, view2.byteLength,
'Expect both arrays to be of the same byte length');
const byteLength = view1.byteLength;
for (let i = 0; i < byteLength; ++i) {
assert_equals(view1.getUint8(i), view2.getUint8(i),
`Expect byte at buffer position ${i} to be equal`);
}
}
// These media tracks will be continually updated with deterministic "noise" in
// order to ensure UAs do not cease transmission in response to apparent
// silence.
//
// > Many codecs and systems are capable of detecting "silence" and changing
// > their behavior in this case by doing things such as not transmitting any
// > media.
//
// Source: https://w3c.github.io/webrtc-pc/#offer-answer-options
const trackFactories = {
// Share a single context between tests to avoid exceeding resource limits
// without requiring explicit destruction.
audioContext: null,
/**
* Given a set of requested media types, determine if the user agent is
* capable of procedurally generating a suitable media stream.
*
* @param {object} requested
* @param {boolean} [requested.audio] - flag indicating whether the desired
* stream should include an audio track
* @param {boolean} [requested.video] - flag indicating whether the desired
* stream should include a video track
*
* @returns {boolean}
*/
canCreate(requested) {
const supported = {
audio: !!window.AudioContext && !!window.MediaStreamAudioDestinationNode,
video: !!HTMLCanvasElement.prototype.captureStream
};
return (!requested.audio || supported.audio) &&
(!requested.video || supported.video);
},
audio() {
const ctx = trackFactories.audioContext = trackFactories.audioContext ||
new AudioContext();
const oscillator = ctx.createOscillator();
const dst = oscillator.connect(ctx.createMediaStreamDestination());
oscillator.start();
return dst.stream.getAudioTracks()[0];
},
video({width = 640, height = 480, signal} = {}) {
const canvas = Object.assign(
document.createElement("canvas"), {width, height}
);
const ctx = canvas.getContext('2d');
const stream = canvas.captureStream();
let count = 0;
const interval = setInterval(() => {
ctx.fillStyle = `rgb(${count%255}, ${count*count%255}, ${count%255})`;
count += 1;
ctx.fillRect(0, 0, width, height);
// Add some bouncing boxes in contrast color to add a little more noise.
const contrast = count + 128;
ctx.fillStyle = `rgb(${contrast%255}, ${contrast*contrast%255}, ${contrast%255})`;
const xpos = count % (width - 20);
const ypos = count % (height - 20);
ctx.fillRect(xpos, ypos, xpos + 20, ypos + 20);
const xpos2 = (count + width / 2) % (width - 20);
const ypos2 = (count + height / 2) % (height - 20);
ctx.fillRect(xpos2, ypos2, xpos2 + 20, ypos2 + 20);
// If signal is set (0-255), add a constant-color box of that luminance to
// the video frame at coordinates 20 to 60 in both X and Y direction.
// (big enough to avoid color bleed from surrounding video in some codecs,
// for more stable tests).
if (signal != undefined) {
ctx.fillStyle = `rgb(${signal}, ${signal}, ${signal})`;
ctx.fillRect(20, 20, 40, 40);
}
}, 100);
if (document.body) {
document.body.appendChild(canvas);
} else {
document.addEventListener('DOMContentLoaded', () => {
document.body.appendChild(canvas);
}, {once: true});
}
// Implement track.stop() for performance in some tests on some platforms
const track = stream.getVideoTracks()[0];
const nativeStop = track.stop;
track.stop = function stop() {
clearInterval(interval);
nativeStop.apply(this);
if (document.body && canvas.parentElement == document.body) {
document.body.removeChild(canvas);
}
};
return track;
}
};
// Get the signal from a video element inserted by createNoiseStream
function getVideoSignal(v) {
if (v.videoWidth < 60 || v.videoHeight < 60) {
throw new Error('getVideoSignal: video too small for test');
}
const canvas = document.createElement("canvas");
canvas.width = canvas.height = 60;
const context = canvas.getContext('2d');
context.drawImage(v, 0, 0);
// Extract pixel value at position 40, 40
const pixel = context.getImageData(40, 40, 1, 1);
// Use luma reconstruction to get back original value according to
// ITU-R rec BT.709
return (pixel.data[0] * 0.21 + pixel.data[1] * 0.72 + pixel.data[2] * 0.07);
}
async function detectSignal(t, v, value) {
while (true) {
const signal = getVideoSignal(v).toFixed();
// allow off-by-two pixel error (observed in some implementations)
if (value - 2 <= signal && signal <= value + 2) {
return;
}
// We would like to wait for each new frame instead here,
// but there seems to be no such callback.
await new Promise(r => t.step_timeout(r, 100));
}
}
// Generate a MediaStream bearing the specified tracks.
//
// @param {object} [caps]
// @param {boolean} [caps.audio] - flag indicating whether the generated stream
// should include an audio track
// @param {boolean} [caps.video] - flag indicating whether the generated stream
// should include a video track, or parameters for video
async function getNoiseStream(caps = {}) {
if (!trackFactories.canCreate(caps)) {
return navigator.mediaDevices.getUserMedia(caps);
}
const tracks = [];
if (caps.audio) {
tracks.push(trackFactories.audio());
}
if (caps.video) {
tracks.push(trackFactories.video(caps.video));
}
return new MediaStream(tracks);
}
// Obtain a MediaStreamTrack of kind using procedurally-generated streams (and
// falling back to `getUserMedia` when the user agent cannot generate the
// requested streams).
// Return Promise of pair of track and associated mediaStream.
// Assumes that there is at least one available device
// to generate the track.
function getTrackFromUserMedia(kind) {
return getNoiseStream({ [kind]: true })
.then(mediaStream => {
const [track] = mediaStream.getTracks();
return [track, mediaStream];
});
}
// Obtain |count| MediaStreamTracks of type |kind| and MediaStreams. The tracks
// do not belong to any stream and the streams are empty. Returns a Promise
// resolved with a pair of arrays [tracks, streams].
// Assumes there is at least one available device to generate the tracks and
// streams and that the getUserMedia() calls resolve.
function getUserMediaTracksAndStreams(count, type = 'audio') {
let otherTracksPromise;
if (count > 1)
otherTracksPromise = getUserMediaTracksAndStreams(count - 1, type);
else
otherTracksPromise = Promise.resolve([[], []]);
return otherTracksPromise.then(([tracks, streams]) => {
return getTrackFromUserMedia(type)
.then(([track, stream]) => {
// Remove the default stream-track relationship.
stream.removeTrack(track);
tracks.push(track);
streams.push(stream);
return [tracks, streams];
});
});
}
// Performs an offer exchange caller -> callee.
async function exchangeOffer(caller, callee) {
await caller.setLocalDescription(await caller.createOffer());
await callee.setRemoteDescription(caller.localDescription);
}
// Performs an answer exchange caller -> callee.
async function exchangeAnswer(caller, callee) {
// Note that caller's remote description must be set first; if not,
// there's a chance that candidates from callee arrive at caller before
// it has a remote description to apply them to.
const answer = await callee.createAnswer();
await caller.setRemoteDescription(answer);
await callee.setLocalDescription(answer);
}
async function exchangeOfferAnswer(caller, callee) {
await exchangeOffer(caller, callee);
await exchangeAnswer(caller, callee);
}
// The returned promise is resolved with caller's ontrack event.
async function exchangeAnswerAndListenToOntrack(t, caller, callee) {
const ontrackPromise = addEventListenerPromise(t, caller, 'track');
await exchangeAnswer(caller, callee);
return ontrackPromise;
}
// The returned promise is resolved with callee's ontrack event.
async function exchangeOfferAndListenToOntrack(t, caller, callee) {
const ontrackPromise = addEventListenerPromise(t, callee, 'track');
await exchangeOffer(caller, callee);
return ontrackPromise;
}
// The resolver extends a |promise| that can be resolved or rejected using |resolve|
// or |reject|.
class Resolver extends Promise {
constructor(executor) {
let resolve, reject;
super((resolve_, reject_) => {
resolve = resolve_;
reject = reject_;
if (executor) {
return executor(resolve_, reject_);
}
});
this._done = false;
this._resolve = resolve;
this._reject = reject;
}
/**
* Return whether the promise is done (resolved or rejected).
*/
get done() {
return this._done;
}
/**
* Resolve the promise.
*/
resolve(...args) {
this._done = true;
return this._resolve(...args);
}
/**
* Reject the promise.
*/
reject(...args) {
this._done = true;
return this._reject(...args);
}
}
function addEventListenerPromise(t, obj, type, listener) {
if (!listener) {
return waitUntilEvent(obj, type);
}
return new Promise(r => obj.addEventListener(type,
t.step_func(e => r(listener(e))),
{once: true}));
}
function createPeerConnectionWithCleanup(t) {
const pc = new RTCPeerConnection();
t.add_cleanup(() => pc.close());
return pc;
}
async function createTrackAndStreamWithCleanup(t, kind = 'audio') {
let constraints = {};
constraints[kind] = true;
const stream = await getNoiseStream(constraints);
const [track] = stream.getTracks();
t.add_cleanup(() => track.stop());
return [track, stream];
}
function findTransceiverForSender(pc, sender) {
const transceivers = pc.getTransceivers();
for (let i = 0; i < transceivers.length; ++i) {
if (transceivers[i].sender == sender)
return transceivers[i];
}
return null;
}
function preferCodec(transceiver, mimeType, sdpFmtpLine) {
const {codecs} = RTCRtpSender.getCapabilities(transceiver.receiver.track.kind);
// sdpFmtpLine is optional, pick the first partial match if not given.
const selectedCodecIndex = codecs.findIndex(c => {
return c.mimeType === mimeType && (c.sdpFmtpLine === sdpFmtpLine || !sdpFmtpLine);
});
const selectedCodec = codecs[selectedCodecIndex];
codecs.slice(selectedCodecIndex, 1);
codecs.unshift(selectedCodec);
return transceiver.setCodecPreferences(codecs);
}
// Contains a set of values and will yell at you if you try to add a value twice.
class UniqueSet extends Set {
constructor(items) {
super();
if (items !== undefined) {
for (const item of items) {
this.add(item);
}
}
}
add(value, message) {
if (message === undefined) {
message = `Value '${value}' needs to be unique but it is already in the set`;
}
assert_true(!this.has(value), message);
super.add(value);
}
}
const iceGatheringStateTransitions = async (pc, ...states) => {
for (const state of states) {
await new Promise((resolve, reject) => {
pc.addEventListener('icegatheringstatechange', () => {
if (pc.iceGatheringState == state) {
resolve();
} else {
reject(`Unexpected gathering state: ${pc.iceGatheringState}, was expecting ${state}`);
}
}, {once: true});
});
}
};
const initialOfferAnswerWithIceGatheringStateTransitions =
async (pc1, pc2, offerOptions) => {
await pc1.setLocalDescription(
await pc1.createOffer(offerOptions));
const pc1Transitions =
iceGatheringStateTransitions(pc1, 'gathering', 'complete');
await pc2.setRemoteDescription(pc1.localDescription);
await pc2.setLocalDescription(await pc2.createAnswer());
const pc2Transitions =
iceGatheringStateTransitions(pc2, 'gathering', 'complete');
await pc1.setRemoteDescription(pc2.localDescription);
await pc1Transitions;
await pc2Transitions;
};
const expectNoMoreGatheringStateChanges = async (t, pc) => {
pc.onicegatheringstatechange =
t.step_func(() => {
assert_unreached(
'Should not get an icegatheringstatechange right now!');
});
};
async function queueAWebrtcTask() {
const pc = new RTCPeerConnection();
pc.addTransceiver('audio');
await new Promise(r => pc.onnegotiationneeded = r);
}
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