Fields in RTCStats dictionary should be required

[soareschen]

The current definition for RTCStats dictionary seems to allow timestamp and id to be optional. For the type field it is only in the description that require it to be initialized. Should all 3 fields be declared as required in the WebIDL definition?

[taylor-b]

I can't find any other normative requirement that forces them to be present, so marking them as required seems sensible.

[aboba]

Typically required is used for dictionaries used as inputs, not outputs.

[soareschen]

Not sure how WebIDL intends dictionaries to be used as return values, but in this spec the RTCSessionDescriptionInit dictionary returned from createOffer/createAnswer also has a required field type.

[taylor-b]

It can be used to construct an RTCSessionDescription (which is possible for backwards compatibility) so that's possibly why.

Anyway, the point I was trying to make above is that if we don't have any normative requirement that says "timestamp MUST be present in returned RTCStats objects", then making it required is a way to implicitly add that requirement, and make it easy to find. Though maybe this is frowned upon and we should ask a WebIDL expert for advice.

[aboba]

@jan-ivar Do you have an opinion?

[jan-ivar]

I do, but I've asked for clarification first in whatwg/webidl#382.

[jan-ivar]

To follow up, my thoughts here are in #1493 (comment). In short, I agree with whatwg/webidl#382 (comment) there's an implicit normative requirement that implementations must fill in this member.