Media element autoplay cannot be tested because supporting it is optional

[foolip]

In https://html.spec.whatwg.org/multipage/embedded-content.html#ready-states the requirements around autoplay are all "may" and there is this note:

User agents do not need to support autoplay, and it is suggested that user agents honor user preferences on the matter. Authors are urged to use the autoplay attribute rather than using script to force the video to play, so as to allow the user to override the behavior if so desired.

Still, when UAs do support autoplay, it is very much possible to test that it has the right timing and that e.g. calling video.pause() causes autoplay to never happen.

To test this, we would need to either strengthen the requirements in HTML, or have some kind of testing API to set the user preference.

@jgraham

[robwalch]

video.play() Promise coverage would be nice :)

[foolip]

@robwalch, do you mean tests for the play promise generically, or specifically around autoplay?

@mounirlamouri FYI

[foolip]

This could be tested now: https://web-platform-tests.org/writing-tests/file-names.html?highlight=.optional