Separate link reference markers from the previous word for screen readers

[Eugene (OEvgeny)]

Screen readers read a link reference marker glued to the previous word in the message summary, such as "Override the proxy settings1." for settings[1].

Changelog Entry

Fixed

• Fixed screen readers gluing a link reference marker to the previous word in the message summary, such as "settings1" for settings[1], in PR #5923, by @OEvgeny

Description

The text alternative of a Markdown message (message summary on arrow keys and live region on arrival) only joined text nodes, so a link or citation button written right after a word, such as [1], became part of that word. A space is now added before a link or button when the text before it does not end with whitespace, so it reads "settings 1.".

Design

• Separate with a space instead of naming the marker (for example "reference 1"): there is no localized string for a single marker, and the link itself already carries its full name.

Specific Changes

• packages/component/src/Utils/activityAltText.ts: add a space before <a> and <button> when glued to the previous text

• accessibility/accessibleName.linkReference.html: new test, asserts the message accessible name and the live region text read "settings 1."; snapshot 1 shows the live region "Override the proxy settings 1." above the transcript "settings[1]."

• I have added tests and executed them locally

• I have updated CHANGELOG.md

• I have updated documentation

Review Checklist

This section is for contributors to review your work.

• Accessibility reviewed (tab order, content readability, alt text, color contrast)
• Browser and platform compatibilities reviewed
• CSS styles reviewed (minimal rules, no z-index)
• Documents reviewed (docs, samples, live demo)
• Internationalization reviewed (strings, unit formatting)
• package.json and package-lock.json reviewed
• Security reviewed (no data URIs, check for nonce leak)
• Tests reviewed (coverage, legitimacy)

[Eugene (OEvgeny)]

TODO: visualize the region via CSS override and take snapshot