make aria-describedby optional for matTooltip

[jasonzhang2022]

Bug, feature request, or proposal:

when matTooltip is used, aria-describedby is auto added. I want to make this optional.

What is the expected behavior?

Make this optional.

What is the current behavior?

It is automatically, there is no way to turn this off.

What are the steps to reproduce?

Providing a StackBlitz reproduction is the best way to share your issue.

StackBlitz starter: https://goo.gl/wwnhMV

What is the use-case or motivation for changing an existing behavior?

when JAWS is used, JAWS ignores aria-describeby during linear navigation.

aria-label can be recognized by all screen reader.

However, If I have both matTooltip, and aria-label, the text will be announced twice by VoiceOver and Vox.

So I intend to use the matTooltip like this

[matTooltip]="my text" aria-label="my text" no-describedby.

By this way, I completely control the accessibility behavior.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

Is there anything else we should know?

[manklu]

Then it would be better to always use aria-label instead of making aria-describedby optional.

[crisbeto]

@jelbourn would it make sense to not add aria-describedby if an aria-label is present?

[jelbourn]

I put this question on the agenda for my next sync with the Google a11y folks