Intent to Ship: Remove PointerEvent.getCoalescedEvents() from insecure contexts

[Mustaq Ahmed]

Contact emails

mus...@chromium.org

Explainer

None

Specification

https://w3c.github.io/pointerevents/#pointerevent-interface

Summary

The Pointer Events Working Group made PointerEvent.getCoalescedEvents() restricted to secure contexts 4+ years ago, which removed the API from insecure contexts. Chrome originally shipped the old behavior and didn't follow the spec change immediately because of compat concerns. We are now removing it from insecure contexts because Chrome usage in insecure contexts turned out to be very low.

Blink component

Blink>Input

TAG review

None

TAG review status

Not applicable

Risks

Interoperability and Compatibility

Interop: This will improves Interop, making Chrome fully match Firefox (and the spec). Compat: There is a bit of risk because the usage is non-zero (~0.0004% as of 2024-07-16). This usage stat is expected to include non-breaking JS enumerations. https://chromestatus.com/metrics/feature/timeline/popularity/4598

Gecko: Shipped/Shipping

WebKit: No signal

Web developers: No signals

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

None

Debuggability

None

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes

https://wpt.fyi/results/pointerevents?label=master&label=experimental&aligned&q=pointerevents%2Fpointerevent_constructor

Flag name on chrome://flags

None

Finch feature name

None

Non-finch justification

None

Requires code in //chrome?

False

Tracking bug

https://issues.chromium.org/40928769

Estimated milestones

Shipping on desktop

129

Shipping on Android

129

Shipping on WebView

129

Anticipated spec changes

Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way).

None

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/4941651093749760?gate=5095189648244736

This intent message was generated by Chrome Platform Status.

[Domenic Denicola]

On Wed, Jul 17, 2024 at 6:52 AM Mustaq Ahmed <mus...@chromium.org> wrote:

Contact emails

mus...@chromium.org

Explainer

None

Specification

https://w3c.github.io/pointerevents/#pointerevent-interface

Summary

The Pointer Events Working Group made PointerEvent.getCoalescedEvents() restricted to secure contexts 4+ years ago, which removed the API from insecure contexts. Chrome originally shipped the old behavior and didn't follow the spec change immediately because of compat concerns. We are now removing it from insecure contexts because Chrome usage in insecure contexts turned out to be very low.

Blink component

Blink>Input

TAG review

None

TAG review status

Not applicable

Risks

Interoperability and Compatibility

Interop: This will improves Interop, making Chrome fully match Firefox (and the spec). Compat: There is a bit of risk because the usage is non-zero (~0.0004% as of 2024-07-16). This usage stat is expected to include non-breaking JS enumerations. https://chromestatus.com/metrics/feature/timeline/popularity/4598

Gecko: Shipped/Shipping

WebKit: No signal

Can you ask for WebKit's position? Or maye there's at least a pointer to working group discussions they participated in?

 

Web developers: No signals

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

None

Debuggability

None

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes

https://wpt.fyi/results/pointerevents?label=master&label=experimental&aligned&q=pointerevents%2Fpointerevent_constructor

Flag name on chrome://flags

None

Finch feature name

None

Non-finch justification

None

Our process requires a Finch feature in general. And this sort of potentially-risky removal seems like the kind of thing that benefits from a Finch feature, so that it can be remotely reverted if it causes terrible regressions.

 

Requires code in //chrome?

False

Tracking bug

https://issues.chromium.org/40928769

Estimated milestones

Shipping on desktop

129

Shipping on Android

129

Shipping on WebView

129

Anticipated spec changes

Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way).

None

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/4941651093749760?gate=5095189648244736

This intent message was generated by Chrome Platform Status.

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[Mustaq Ahmed]

> Can you ask for WebKit's position? Or maye there's at least a pointer to working group discussions they participated in?

- Safari doesn't yet support PointerEvent.getCoalescedEvents(), so we can't ask for their position on secure/non-secure context differences:

https://developer.mozilla.org/en-US/docs/Web/API/PointerEvent/getCoalescedEvents#browser_compatibility

- Here is a PEWG discussion started by @gsnedders from WebKit (I couldn't find any other related discussion Safari participated in):

https://github.com/w3c/pointerevents/issues/215

> Our process requires a Finch feature in general. And this sort of potentially-risky removal seems like the kind of thing that benefits from a Finch feature, so that it can be remotely reverted if it causes terrible regressions.

Unfortunately we can't put this change behind a flag because Blink does not allow making [SecureContext] conditional.  I think it was supported in the past because "Blink IDL Extended Attributes" documentation still mentions [SecureContext=flag] as non-standard, but it doesn't even compile!

https://chromium.googlesource.com/chromium/src/+/HEAD/third_party/blink/renderer/bindings/IDLExtendedAttributes.md#securecontext

[Mike Taylor]

On 7/17/24 10:18 AM, Mustaq Ahmed wrote:

> Can you ask for WebKit's position? Or maye there's at least a pointer to working group discussions they participated in?

- Safari doesn't yet support PointerEvent.getCoalescedEvents(), so we can't ask for their position on secure/non-secure context differences:

https://developer.mozilla.org/en-US/docs/Web/API/PointerEvent/getCoalescedEvents#browser_compatibility

That's OK - we ask for positions from them all the time for things they don't support.

- Here is a PEWG discussion started by @gsnedders from WebKit (I couldn't find any other related discussion Safari participated in):

https://github.com/w3c/pointerevents/issues/215

To my knowledge, that was posted a few years before Sam started working at Apple.

To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAB0cuO4wETXcy7h%3D8S586WccqRj5jDX0_zaSJfvdtzyv3pU2Ew%40mail.gmail.com.

[Mustaq Ahmed]

On Wed, Jul 17, 2024 at 2:20 PM Mike Taylor <mike...@chromium.org> wrote:

On 7/17/24 10:18 AM, Mustaq Ahmed wrote:

> Can you ask for WebKit's position? Or maye there's at least a pointer to working group discussions they participated in?

- Safari doesn't yet support PointerEvent.getCoalescedEvents(), so we can't ask for their position on secure/non-secure context differences:

https://developer.mozilla.org/en-US/docs/Web/API/PointerEvent/getCoalescedEvents#browser_compatibility

That's OK - we ask for positions from them all the time for things they don't support.

Done: https://github.com/WebKit/standards-positions/issues/374 

- Here is a PEWG discussion started by @gsnedders from WebKit (I couldn't find any other related discussion Safari participated in):

https://github.com/w3c/pointerevents/issues/215

To my knowledge, that was posted a few years before Sam started working at Apple.

I missed this, sorry.  My corrected answer is: "I couldn't find any PEWG discussion on Coalesced Events where Safari participated".

[Domenic Denicola]

LGTM1. It's a bit scary doing this without a Finch flag, but the usage is very low and such pages are already broken in Firefox.

[Mike Taylor]

Could you also request the Enterprise bit?

In the meantime - I'd love to know more about `[SecureContext=flag]` not working - that capability was introduced to make these types of roll outs safer, IIRC. In the past I've had to write postmortems because I thought usage was low enough, but the breakage was in enterprise environments that disable telemetry... and didn't have a finch flag to quickly revert. :(

(I'm also not trying to send you on an impossible side-quest, but won't be sad if someone is nerd sniped into fixing what feels like a regression).

[Mustaq Ahmed]

On Mon, Jul 22, 2024 at 2:53 PM Mike Taylor <mike...@chromium.org> wrote:

Could you also request the Enterprise bit?

I missed flipping the bit after filling out the enterprise survey questions!  Done.

In the meantime - I'd love to know more about `[SecureContext=flag]` not working - that capability was introduced to make these types of roll outs safer, IIRC. In the past I've had to write postmortems because I thought usage was low enough, but the breakage was in enterprise environments that disable telemetry... and didn't have a finch flag to quickly revert. :(

(I'm also not trying to send you on an impossible side-quest, but won't be sad if someone is nerd sniped into fixing what feels like a regression).

Reached out to the team who might know about the change.

[Chris Harrelson]

LGTM2

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[Philip Jägenstedt]

LGTM3. If it is possible to use a finch flag for this removal, please do, but if not please keep an eye out for any regression and revert at the first sign of trouble. 

To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw9ezoFK2C6H8NbuBWF4r355Eg%3Dw%2BJZCSsgXMEEz_on61A%40mail.gmail.com.