[cssom-view] For UX consistency, should history interface respect scrollport's scroll-behavior?

[jonjohnjohnson]

https://drafts.csswg.org/cssom-view-1/#propdef-scroll-behavior

Recently, been taking advantage of scroll-behavior: smooth, but when either using a supporting browsers forward/back buttons or programmatically interacting with the history interface, the property/behavior isn't respected, always showcasing what would be the auto (or the old instant) value.

The spec says...

The scroll-behavior property specifies the scrolling behavior for a scrolling box, when scrolling happens due to navigation or CSSOM scrolling APIs

I could interpret that as meaning the behavior seen in browsers are issues with implementation, but I'm not sure. And if so, could the spec be clearer so that if a clicked "jumplink" exhibits support for the scroll-behavior property, then that same behavior would be respected if the user clicks back/forwards or performs an action that manipulates the history interface?

[jonjohnjohnson]

@annevk I see you were a previous editor on this module, that currently has no editor. If you have any insights, especially if this is solely implementations not adhering to the specification, I can close this and file reports with each vendor.

[annevk]

It's probably worth keeping this open until it's covered by the test suite somehow. You're correct that these are bugs (history traversal == navigation). If you file bugs, please link them from here.

[jonjohnjohnson]

Chrome -> https://bugs.chromium.org/p/chromium/issues/detail?id=830971
Firefox -> https://bugzilla.mozilla.org/show_bug.cgi?id=1452825

Both engines above seem to have *mostly fixed this, though we still need to get tests.