Should empty string icecandidate be added by addicecandidate? - webrtc

Question

My question is about webrtc negotiation.
There is a contradiction in many online tutorials and what is described in MDN.
In MDN, it says link
At the end of each generation of candidates, an end-of-candidates
notification is sent in the form of an RTCIceCandidate whose candidate
property is an empty string. This candidate should still be added to
the connection using addIceCandidate() method, as usual, in order to
deliver that notification to the remote peer.
When there are no more candidates at all to be expected during the
current negotiation exchange, an end-of-candidates notification is
sent by delivering a RTCIceCandidate whose candidate property is null.
This message does not need to be sent to the remote peer. It's a
legacy notification of a state which can be detected instead by
watching for the iceGatheringState to change to complete, by watching
for the icegatheringstatechange event.
However, in the tutorial here, they introduce the following code
function handleICECandidateEvent(event) {
if (event.candidate) {
sendToServer({
type: "new-ice-candidate",
target: targetUsername,
candidate: event.candidate
});
}
}
If candidate is an empty string, it will be evaluated falsy and not be sent via sendToServer.
More interestingly, even in a same article here
They have following sample code
rtcPeerConnection.onicecandidate = (event) => {
if (event.candidate) {
sendCandidateToRemotePeer(event.candidate)
}
}
But right below this snippet, they say
When an ICE negotiation session runs out of candidates to propose for
a given RTCIceTransport, it has completed gathering for a generation
of candidates. That this has occurred is indicated by an icecandidate
event whose candidate string is empty ("").
You should deliver this to the remote peer just like any standard candidate, as described under Sharing a new candidate above. This
ensures that the remote peer is given the end-of-candidates
notification as well.
Actually, I read many online tutorials but I have never seen anywhere where they handle the empty string candidate.

Answer 1

The old spec did not require sending an empty candidate, but the new spec require send and addIceCandidate() an empty candidate.
Since Chrome is still an old specification, an empty candidate will cause an error when addedIceCandidate(), so I will not send it.