Error summary markup needs to be updated to follow GOV.UK

[edwardhorsford]

Bug Report

Whilst testing the error summary with VoiceOver on Safari, I observe that 'There is a problem' gets read out twice. I think this is because the error summary itself is aria-labelledby the title, and then Voiceover also reads the contents of the error summary - first of which is the title.

Comparing to GOV.UK, their markup updated in v4.4 to move the alert to a child element and adjust other bits for screen readers.

[edwardhorsford]

Video of error summary title getting read out twice:
https://github.com/user-attachments/assets/5144e891-ef00-479e-a573-8f312ac3e782