1536860 - Add telemetry and warning for Array generics

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement, P2)

Description

[Tom S [:evilpie]]

Adding a warning for Array generics might be a bit annoying because Firefox code is still using it!

Comment 1

[Tom S [:evilpie]]

Attachment: Bug 1536860 - Warn about deprecated Array generics. r?jorendorff

Comment 2

[Tom S [:evilpie]]

Attachment: Bug 1536860 - Telemetry for deprecated Array generics. r?jorendorff datareview=chutten

Depends on D24207

Comment 3

[Tom S [:evilpie]]

Attachment: data-review

Similar to what we already added before for Strings now for Arrays. (bug 1339777)

Comment 4

[Chris H-C :chutten]

Comment on attachment 9052672 [details]
data-review

DATA COLLECTION REVIEW RESPONSE:

    Is there or will there be documentation that describes the schema for the ultimate data set available publicly, complete and accurate?

Yes. This collection is Telemetry so is documented in its definitions file [Histograms.json](https://hg.mozilla.org/mozilla-central/file/tip/toolkit/components/telemetry/Histograms.json) and the [Probe Dictionary](https://telemetry.mozilla.org/probe-dictionary/).

    Is there a control mechanism that allows the user to turn the data collection on and off?

Yes. This collection is Telemetry so can be controlled through Firefox's Preferences.

    If the request is for permanent data collection, is there someone who will monitor the data over time?

No. This collection will expire in Firefox 74.

    Using the category system of data types on the Mozilla wiki, what collection type of data do the requested measurements fall under?

Category 1, Technical.

    Is the data collection request for default-on or default-off?

Default on for pre-release channels only.

    Does the instrumentation include the addition of any new identifiers?

No.

    Is the data collection covered by the existing Firefox privacy notice?

Yes.

    Does there need to be a check-in in the future to determine whether to renew the data?

Yes. :evilpie is responsible for renewing or removing the collection before it expires in Firefox 74.

---
Result: datareview+

Comment 5

[Tom S [:evilpie]]

Attachment: Bug 1536860 - Remove Array.slice from lib/asm.js. r?jorendorff

This was causing test failures in some uncommon try configurations like fuzzing.

Depends on D24208

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/631bf8533698
Warn about deprecated Array generics. r=jorendorff
https://hg.mozilla.org/integration/autoland/rev/65339ae085f7
Telemetry for deprecated Array generics. r=jorendorff datareview=chutten
https://hg.mozilla.org/integration/autoland/rev/f497764d0e13
Remove Array.slice from lib/asm.js. r=jorendorff

Comment 7

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/631bf8533698
https://hg.mozilla.org/mozilla-central/rev/65339ae085f7
https://hg.mozilla.org/mozilla-central/rev/f497764d0e13

Comment 8

[Florian Quèze [:florian]]

(In reply to Tom Schuster [:evilpie] from comment #0)

Adding a warning for Array generics might be a bit annoying because Firefox code is still using it!

Yes, this is indeed annoying. Could the warning be disabled for privileged code? If you want to eliminate a pattern from the Firefox codebase, it's more efficient to do it with a scripted rewrite of the code, or with eslint rules.

Comment 9

[Kohei Yoshino [:kohei]]

Posted site compatibility note: https://www.fxsitecompat.com/en-CA/docs/2019/non-standard-array-generics-have-been-deprecated/