Attributes potentially incorrectly set to introduced in Chrome 44

[foolip]

The kind of issue with attributes, and in particular length attributes, mentioned in #7749 (review) appears to already have happened in BCD.

These are attributes claimed to be introduced in Chrome 44 that need double checking:

• api.AudioBufferSourceNode.detune
• api.CSSKeyframesRule.cssRules
• api.CSSKeyframesRule.name
• api.CSSStyleDeclaration.length
• api.Document.scrollingElement
• api.HTMLAllCollection.length
• api.TextTrackList.length

[foolip]

#7843 is similar, but for Chrome 43.

[ddbeck]

I don't follow the problem for length here. Can you elaborate on what we're talking about here? The linked review wasn't particularly illuminating (just "suspicious").

[foolip]

I haven't looked into the details, but length properties seem to often be different from other attributes, appearing on instances rather than on the prototype even after the point where attributes in general moved from the instances to prototypes in various engines.

But in addressing this issue there's no need to handle length properties differently, like for all attributes we just need to check if they're on an instance rather than just looking at the prototype.

[queengooborg]

I researched this and found the following info:

• api.AudioBufferSourceNode.detune - Comes from Corrections to Web Audio #1579, confirmed by the collector
• api.CSSKeyframesRule.cssRules - Comes from Update Chrome data for CSSKeyframesRule API #6908, collector test is returning "null"
• api.CSSKeyframesRule.name - Also comes from Update Chrome data for CSSKeyframesRule API #6908, collector test is returning "null"
• api.CSSStyleDeclaration.length - Comes from Update data for CSSStyleDeclaration API #6976, collector now says "1"
• api.Document.scrollingElement - Comes from Add compat data for Document #1324 (wiki migration), but collector agrees
• api.HTMLAllCollection.length - Comes from Add data for misc. collections. #2470 (wiki migration), collector now says "6"
• api.TextTrackList.length - Updated in Update Chromium versions for api.TextTrackList.length #14352

I'll submit PRs for these!

[queengooborg]

PRs have been submitted for the two I'm able to update at this point -- I plan to follow up with CSSKeyframesRule in the future, once the test is fixed!

[foolip]

@queengooborg did you mean to close this even though the fixes aren't landed yet?

[queengooborg]

I did, with the thought that we will follow up with collector results as it is. If you'd prefer, we can keep it open until the collector's fixed and the data has all been fixed!

[foolip]

I ran npm run traverse chrome api 44 again and this isn't totally fixed yet, I've confirmed the following are wrong because they're in Chrome 43 per the collector:

• api.CSSKeyframesRule.cssRules
• api.CSSKeyframesRule.name
• api.CSSStyleDeclaration.length

[foolip]

With #15864 merged only CSSKeyframesRule remains from the original list.

[foolip]

Two more that will need to be checked, added since I filed this issue:

• api.Notification.data
• api.Response.redirect

[foolip]

https://mdn-bcd-collector.appspot.com/tests/api/Notification/data confirmed with Chrome 43/44, and that test doesn't use prototype testing.

[foolip]

api.Response.redirect is a method, so can't have this problem. Closing.