[Feature] Announce Snackbar appearance to screen reader

[TimRoe]

Description of Change

Recognized the issue with the screen reader not reading the announceForAccessibility was only a problem in iOS and it appeared to be an issue due to the synchronous nature of the storybook test case so iOS was immediately refocusing the button at near enough the same time to not do the announceForAccessibility.

Resolved by creating a useEffect on the Snackbar display that:

1. Has an empty dependency array so the useEffect is only run once on initial render since otherwise the announceForAccessibility was being triggered multiple times (on appearance and disappearance)
2. Has a 50ms delay so that if whatever is bringing up the Snackbar is synchronous (not generally how it's used, but could be) it still announces correctly

Testing Packages

• 0.21.1-alpha.10

Screenshots/Video

iOS:

RPReplay_Final1723481022.MP4

Android:

Screen_Recording_20240812-125152_Expo.Go.mp4

Flagship iOS (somewhat janky from app-level focus that they'll need to address during implementation):

RPReplay_Final1723483670.MP4

Flagship Android (also somewhat janky in a different way from app-level focus that they'll need to address during implementation):

Screen_Recording_20240812-133427_VA.mp4

Testing

Tested it performs as expected in Storybook. Also tested flagship which was a bit janky, but due to app-level setting focus.

• Tested on iOS
• Tested on Android
• Tested on Web
  • N/A

PR Checklist

Code reviewer validation:

• General
  • PR is linked to ticket(s)
  • PR has changelog label applied if it's to be included in the changelog
  • Acceptance criteria:
    • All satisfied or
    • Documented reason for not being performed or
    • Split to separate ticket and ticket is linked by relevant AC(s)
  • Above PR sections adequately filled out
  • If any breaking changes, in accordance with the pre-1.0.0 versioning guidelines: a CU ticket has been created for the VA Mobile App detailing necessary adjustments with the package version that will be published by this ticket
• Code
  • Tests are included if appropriate (or split to separate ticket)
  • New functions have proper TSDoc annotations

Publish

While changes do warrant a new version per the versioning guidelines, postponed for later following functional changes to Snackbar.

[narin]

Looks good. Did you identify how the app would fix the jankiness? If so we should make note of it in the implementation ticket.

[TimRoe]

Did you identify how the app would fix the jankiness?

I did not.

It may involve changes on our end. There is a slightly different function, announceForAccessibilityWithOptions, which can make iOS queue up the announcement behind other screen reader behavior similar to how Android behaves. There's also settings for Android to be assertive and interrupt, but not sure how easily we can apply that to announceForAccessibility. There's enough ambiguity that I think we can leave it to flagship implementing and work with them on how best to sort it out then.

I have added a comment to the handoff ticket so they are on the lookout for it at least.