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accessibility-aria-expert

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by microsoft · part of microsoft/vscode-cosmosdb

Detects and fixes accessibility issues in React/Fluent UI webviews. Use when reviewing code for screen reader compatibility, fixing ARIA labels, ensuring…

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Detects and fixes accessibility issues in React/Fluent UI webviews. Use when reviewing code for screen reader compatibility, fixing ARIA labels, ensuring…

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name: accessibility-aria-expert description: Detects and fixes accessibility issues in React/Fluent UI webviews. Use when reviewing code for screen reader compatibility, fixing ARIA labels, ensuring keyboard navigation, adding live regions for status messages, or managing focus in dialogs.

Accessibility Expert for Webviews

Verify and fix accessibility in React/Fluent UI webview components.

When to Use

  • Review webview code for accessibility issues
  • Fix double announcements from screen readers
  • Add missing aria-label to icon-only buttons or form inputs
  • Make tooltips accessible to keyboard/screen reader users
  • Announce status changes (loading, search results, errors)
  • Manage focus when dialogs/modals open
  • Group related controls with proper labels

Core Pattern: Tooltip Accessibility

Tooltips require aria-label + aria-hidden to avoid double announcements:

Copy & paste — that's it
<Tooltip content="Detailed explanation">
  <Badge tabIndex={0} className="focusableBadge" aria-label="Badge text. Detailed explanation">
    <span aria-hidden="true">Badge text</span>
  </Badge>
</Tooltip>
  • aria-label: Full context (visible text + tooltip)
  • aria-hidden="true": Wraps visible text to prevent duplication
  • Screen reader hears: "Badge text. Detailed explanation"

Detection Rules

1. Tooltip Without aria-label Context

Problem: Tooltip content inaccessible to screen readers

Copy & paste — that's it
<Tooltip content="Save document to database">
  <Button aria-label="Save">Save</Button>
</Tooltip>

Fix: Include tooltip in aria-label

Copy & paste — that's it
<Tooltip content="Save document to database" relationship="description">
  <Button aria-label="Save document to database">Save</Button>
</Tooltip>

2. Missing aria-hidden (Double Announcement)

Problem: Screen reader says "Collection scan Collection scan"

Copy & paste — that's it
<Badge aria-label="Collection scan. Query is inefficient">Collection scan</Badge>

Fix: Wrap visible text

Copy & paste — that's it
<Badge aria-label="Collection scan. Query is inefficient">
  <span aria-hidden="true">Collection scan</span>
</Badge>

3. Redundant aria-label (NOT Needed)

Problem: aria-label identical to visible text adds no value

Copy & paste — that's it
<Button aria-label="Save">Save</Button>
<ToolbarButton aria-label="Validate" icon={<CheckIcon />}>Validate</ToolbarButton>

Fix: Remove redundant aria-label OR make it more descriptive

Copy & paste — that's it
<Button>Save</Button>
<ToolbarButton icon={<CheckIcon />}>Validate</ToolbarButton>

Keep aria-label only when it adds information:

Copy & paste — that's it
<ToolbarButton aria-label="Save document to database" icon={<SaveIcon />}>
  Save
</ToolbarButton>

4. Icon-Only Button Missing aria-label

Problem: No accessible name

Copy & paste — that's it
<ToolbarButton icon={<DeleteRegular />} onClick={onDelete} />

Fix: Add aria-label

Copy & paste — that's it
<Tooltip content="Delete selected items" relationship="description">
  <ToolbarButton aria-label="Delete selected items" icon={<DeleteRegular />} onClick={onDelete} />
</Tooltip>

5. Decorative Elements Not Hidden

Problem: Progress bar announced unnecessarily

Copy & paste — that's it
<ProgressBar thickness="large" />

Fix: Hide decorative elements

Copy & paste — that's it
<ProgressBar thickness="large" aria-hidden={true} />

6. Input Missing Accessible Name

Problem: SpinButton/Input without accessible name

Copy & paste — that's it
<SpinButton value={skipValue} onChange={onSkipChange} />
<Input placeholder="Enter query..." />

Fix: Add aria-label or associate with label element

Copy & paste — that's it
<SpinButton aria-label="Skip documents" value={skipValue} onChange={onSkipChange} />
<Label htmlFor="query-input">Query</Label>
<Input id="query-input" placeholder="Enter query..." />

7. Visible Label Not in Accessible Name

Problem: aria-label doesn't contain visible text (breaks voice control)

Copy & paste — that's it
<ToolbarButton aria-label="Reload data" icon={<RefreshIcon />}>
  Refresh
</ToolbarButton>

Fix: Accessible name must contain visible label exactly

Copy & paste — that's it
<ToolbarButton aria-label="Refresh data" icon={<RefreshIcon />}>
  Refresh
</ToolbarButton>

Voice control users say "click Refresh" – only works if accessible name contains "Refresh".

8. Status Changes Not Announced

Problem: Screen reader doesn't announce dynamic content

Copy & paste — that's it
<span>{isLoading ? 'Loading...' : `${count} results`}</span>

Fix: Use the Announcer component

Copy & paste — that's it
import { Announcer } from '../../api/webview-client/accessibility';

// Announces when `when` transitions from false to true
<Announcer when={isLoading} message={l10n.t('Loading...')} />

// Dynamic message based on state
<Announcer
    when={!isLoading && documentCount !== undefined}
    message={documentCount > 0 ? l10n.t('Results found') : l10n.t('No results found')}
/>

Use for: loading states, search results, success/error messages.

9. Dialog Opens Without Focus Move

Problem: Focus stays on trigger when modal opens

Copy & paste — that's it
{
  isOpen && <Dialog>...</Dialog>;
}

Fix: Move focus programmatically

Copy & paste — that's it
const dialogRef = useRef<HTMLDivElement>(null);

useEffect(() => {
  if (isOpen) dialogRef.current?.focus();
}, [isOpen]);

{
  isOpen && (
    <Dialog ref={dialogRef} tabIndex={-1} aria-modal="true">
      ...
    </Dialog>
  );
}

10. Related Controls Without Group Label

Problem: Buttons share visual label but screen reader misses context

Copy & paste — that's it
<span>How would you rate this?</span>
<Button>👍</Button>
<Button>👎</Button>

Fix: Use role="group" with aria-labelledby

Copy & paste — that's it
<div role="group" aria-labelledby="rating-label">
  <span id="rating-label">How would you rate this?</span>
  <Button aria-label="I like it">👍</Button>
  <Button aria-label="I don't like it">👎</Button>
</div>

When to Use aria-hidden

DO use on:

  • Visible text when aria-label provides complete context
  • Decorative icons, spinners, progress bars
  • Visual separators (`|`, `—`)

DO NOT use on:

  • The only accessible content (hides it completely)
  • Interactive/focusable elements
  • Error messages or alerts

focusableBadge Pattern

For keyboard-accessible badges with tooltips:

  1. Import: `import '../components/focusableBadge/focusableBadge.scss';`
  2. Apply attributes:
Copy & paste — that's it
<Badge tabIndex={0} className="focusableBadge" aria-label="Visible text. Tooltip details">
  <span aria-hidden="true">Visible text</span>
</Badge>

Screen Reader Announcements

Use the Announcer component for WCAG 4.1.3 (Status Messages) compliance.

Copy & paste — that's it
import { Announcer } from '../../api/webview-client/accessibility';

Basic Usage

Copy & paste — that's it
// Announces "AI is analyzing..." when isLoading becomes true
<Announcer when={isLoading} message={l10n.t('AI is analyzing...')} />

// Dynamic message based on state (e.g., query results)
<Announcer
    when={!isLoading && documentCount !== undefined}
    message={documentCount > 0 ? l10n.t('Results found') : l10n.t('No results found')}
/>

// With assertive politeness (default is polite)
<Announcer when={hasError} message={l10n.t('Error occurred')} politeness="assertive" />

Props

  • when: Announces when this transitions from false to true
  • message: The message to announce (use l10n.t() for localization)
  • politeness: 'assertive' (default, interrupts) or 'polite' (waits for idle)

Key Points

  • Placement doesn't matter - screen readers monitor all live regions regardless of DOM position; place near related UI for code readability
  • Store relevant state (e.g., documentCount) to derive dynamic messages
  • Use l10n.t() for messages - announcements must be localized
  • Condition resets automatically - when when goes back to false, it's ready for the next announcement
  • Prefer 'assertive' for user-initiated actions, 'polite' for background updates

Quick Checklist

  • Icon-only buttons have aria-label
  • Form inputs have associated labels or aria-label
  • Tooltip content included in aria-label
  • Visible text wrapped in aria-hidden="true" when aria-label duplicates it
  • Redundant aria-labels removed (identical to visible text)
  • Visible button labels match accessible name exactly (for voice control)
  • Decorative elements have aria-hidden={true}
  • Badges with tooltips use focusableBadge class + tabIndex={0}
  • Status updates use Announcer component
  • Focus moves to dialog/modal content when opened
  • Related controls wrapped in role="group" with aria-labelledby

References