Created attachment 316256 [details]
Demo showing VoiceOver not announcing which fields have failed validation
When using the `required` attribute on form fields, when the focus is taken to the first field with errors, its label is not announced by VoiceOver; it just tells you to "Fill out this field", which is essentially useless for a blind user.
In this test case, https://jsfiddle.net/8c9qge88/, it happens when triggering the button with Enter, Space and VO Space on the button. On my more complex implementation in a WIP project, it always happens on Space, often happens on Enter and never happens on VO Space :-\
Also reproduced this behavior in Safari 10+