Re: Error types (Re: Notes, April 16)

Den 22. april 2015 10:24, skrev Dan Burnett:
> 
> On Apr 22, 2015, at 2:43 AM, Harald Alvestrand wrote:
> 
>> Den 21. april 2015 21:42, skrev Dan Burnett:
>>>>> #140 declaration for error type: Dan - need to make sure we have
>>>>> consistent errors.
>>> Not sure how I got assigned this fun one, but I guess that's what I get for having to drop off 10 mins early :)  This is now looking like a more comprehensive change, in both specs perhaps.
>>>
>>
>> We have a bug (from Anne I believe) to make sure we do the right thing
>> on getusermedia wrt errors. Our stance of "we declare what we want to
>> have, and wait for the webidl / ecmascript landscape to stop moving"
>> seems to have been the right one.
>>
> 
> Yes, that's what I was referring to.  In the case of the gUM spec it's a single new Error "subclass", but for the WebRTC spec we currently have several:
> - RTCSDPError
> - RTCIdentityError (possibly modified to differentiate idpassertionerror from idpvalidationerror)
> - possibly a new RTCIceCandidateError for the TBDs there
> - InvalidSessionDescriptionError, IncompatibleSessionDescriptionError, IncompatibleConstraintsError, and InternalError.  Any of these we keep would need RTC prefixes.
> 

I'm hoping that we can get away with:

- A very small number of new Error "subclasses" for the cases where we
need to add extra information to the error. Some people seem to dislike
these intensely, but I do think we have to have them.

- A somewhat larger number of new Error *name* values, where we add no
new information. There seems to be much smaller resistance to that.

The ECMAScript 6 spec seems to mix these two concepts together somehow,
with language that sounds like "the name always reflects the name of the
class". That sounds like a weird way to do things, especially when using
prose not markup for the definition, but if we have to, we have to.

> At this point I'm thinking I should
> - email the Media Cap list with a pointer to Domenic's suggestion for MediaStreamError as a sanity check on the approach of defining custom Error subclasses as Domenic describes.  The change itself can then be a pull request before it goes in.
> - provide the list of new Error subclasses I think we need for WebRTC on the webrtc list, with a ref to the Media Cap email as an example of how it can be done.  Assuming there is general agreement on the list, I (and/or others) can then create one or more PRs for the changes that can be reviewed before they go in.
> 
> Thoughts?

Seems like a plan. Domenic needs to be in the loop to make sure we
understood him correctly, of course.

Received on Wednesday, 22 April 2015 08:42:44 UTC