1388119 - Drop support for ErrorEvent and PopStateEvent in createEvent

Status: RESOLVED FIXED

(Core :: DOM: Events, enhancement)

Description

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

https://github.com/whatwg/dom/issues/362
https://github.com/whatwg/dom/pull/489

ErrorEvent is certainly safe to drop, since we only added it in bug 1333901, because the spec didn't indicate that the list had been under discussion for months and was likely to change.  :(

PopStateEvent is not supported by WebKit in createEvent (according to my testing last November), and we and Blink support it but have no means to initialize it.  Edge does support it, with an initializer.  IIRC, Telemetry showed ~0 uses, although the telemetry page is taking many minutes to load, so I can't provide a working link right now.

Comment 1

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

Oh, yes, and foolip intends to try dropping support for these events in Blink as well, and thinks he'll succeed because the usage is very low.

https://www.chromestatus.com/metrics/feature/timeline/popularity/1170
https://www.chromestatus.com/metrics/feature/timeline/popularity/1176

PopStateEvent for Chrome is hit by less than 0.000001% of pages.

Comment 2

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

Attachment: Bug 1388119 - Drop support for createEvent("ErrorEvent"/"PopStateEvent");

They were just dropped from the spec:

https://github.com/whatwg/dom/issues/362
https://github.com/whatwg/dom/pull/489

ErrorEvent we never supported anyway until it was added recently to
match the spec.  PopStateEvent is not supported by WebKit, Blink is
planning to try dropping support, our telemetry shows usage is
basically zero, and we never supported any way to initialize it anyway.

Review commit: https://reviewboard.mozilla.org/r/165772/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/165772/

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

Comment on attachment 8894608 [details]
Bug 1388119 - Drop support for createEvent("ErrorEvent"/"PopStateEvent");

https://reviewboard.mozilla.org/r/165772/#review170858

Comment 4

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

Comment on attachment 8894608 [details]
Bug 1388119 - Drop support for createEvent("ErrorEvent"/"PopStateEvent");

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/165772/diff/1-2/

Comment 5

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

Comment on attachment 8894608 [details]
Bug 1388119 - Drop support for createEvent("ErrorEvent"/"PopStateEvent");

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/165772/diff/2-3/

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b668f3429c7f
Drop support for createEvent("ErrorEvent"/"PopStateEvent"); r=smaug

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/b668f3429c7f