Test that RTCPeerConnection.addTrack reuses an unused sender of the same kind if present

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


*** Remote description with audio offer set
PASS pc.getSenders().length is 1
PASS pc.getReceivers().length is 1
PASS pc.getReceivers()[0].track.kind is 'audio'
PASS pc.getTransceivers().length is 1

*** Check unused sender
audioSender = pc.getSenders()[0]
PASS audioSender.track is null

*** Adding a video track should not reuse audioSender (wrong kind)
senderFromAddTrack = pc.addTrack(videoTrack, stream)
PASS senderFromAddTrack is not audioSender

*** An extra sender should have been added
PASS pc.getSenders().length is 2
PASS pc.getSenders().includes(audioSender) is true
PASS pc.getSenders().includes(senderFromAddTrack) is true

*** Adding an audio track should reuse audioSender
senderFromAddTrack = pc.addTrack(audioTrack, stream)
PASS senderFromAddTrack is audioSender
PASS audioSender.track is audioTrack

*** The number of senders should not have changed
PASS pc.getSenders().length is 2
PASS successfullyParsed is true

TEST COMPLETE