Accessibility Automation Expert

Implement and enforce WCAG 2.2 AA/AAA compliance through automated testing, keyboard navigation, ARIA patterns, screen reader optimization, and focus management.

Activation Triggers

Activate on: accessibility audit failures, WCAG compliance requirements, keyboard navigation broken, screen reader not announcing content, axe-core violations, focus trap for modals/dialogs, aria-* attribute questions, skip navigation links.

NOT for: design-level accessibility review (color choices, layout decisions) -- use design-accessibility-auditor. Pure color contrast checking -- use css-in-js-architect with OKLCH.

Quick Start

1. Run axe-core -- npx @axe-core/cli http://localhost:3000 or integrate @axe-core/react in dev mode for console warnings.
2. Fix critical violations first -- missing alt text, missing form labels, insufficient contrast, missing landmarks.
3. Implement keyboard navigation -- every interactive element must be reachable and operable with Tab, Enter, Space, Escape, and Arrow keys.
4. Add focus management -- trap focus in modals, restore focus on close, manage focus on route change.
5. Test with a screen reader -- VoiceOver (macOS), NVDA (Windows), or TalkBack (Android) for real validation.

Core Capabilities

Domain	Technologies	Key Patterns
Automated Testing	axe-core, Lighthouse, jest-axe, Playwright axe	CI/CD accessibility gates
Keyboard Navigation	tabindex, onKeyDown, roving tabindex	Arrow key navigation, focus groups
Screen Readers	ARIA roles, live regions, aria-label	Announcements, state changes, descriptions
Focus Management	focus-visible, focus trap, inert attribute	Modal focus lock, skip links, route change focus
Semantic HTML	<main>, <nav>, <article>, <aside>	Landmarks, heading hierarchy, lists
Forms	<label>, aria-describedby, aria-invalid	Error announcement, required fields, fieldsets

Architecture Patterns

Pattern 1: Automated axe-core in CI

// e2e/accessibility.spec.ts (Playwright + axe-core)
import { test, expect } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';

const pages = ['/', '/products', '/checkout', '/account'];

for (const path of pages) {
  test(`${path} has no accessibility violations`, async ({ page }) => {
    await page.goto(path);
    await page.waitForLoadState('networkidle');

    const results = await new AxeBuilder({ page })
      .withTags(['wcag2a', 'wcag2aa', 'wcag22aa'])  // WCAG 2.2 AA
      .analyze();

    expect(results.violations).toEqual([]);
  });
}

// Dev mode: axe-core in React (shows violations in console)
// app/layout.tsx
if (process.env.NODE_ENV === 'development') {
  import('@axe-core/react').then((axe) => {
    axe.default(React, ReactDOM, 1000);
  });
}

Pattern 2: Focus Management for Modals

import { useEffect, useRef, useCallback } from 'react';

function useFocusTrap(isOpen: boolean) {
  const containerRef = useRef<HTMLDivElement>(null);
  const previousFocusRef = useRef<HTMLElement | null>(null);

  useEffect(() => {
    if (!isOpen) return;

    // Save current focus to restore later
    previousFocusRef.current = document.activeElement as HTMLElement;

    // Focus first focusable element
    const container = containerRef.current;
    if (!container) return;

    const focusable = container.querySelectorAll<HTMLElement>(
      'a[href], button:not([disabled]), input:not([disabled]), textarea:not([disabled]), select:not([disabled]), [tabindex]:not([tabindex="-1"])'
    );
    focusable[0]?.focus();

    // Trap focus within container
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key !== 'Tab') return;
      const first = focusable[0];
      const last = focusable[focusable.length - 1];

      if (e.shiftKey && document.activeElement === first) {
        e.preventDefault();
        last?.focus();
      } else if (!e.shiftKey && document.activeElement === last) {
        e.preventDefault();
        first?.focus();
      }
    };

    container.addEventListener('keydown', handleKeyDown);

    // Use inert on background content
    const mainContent = document.querySelector('main');
    mainContent?.setAttribute('inert', '');

    return () => {
      container.removeEventListener('keydown', handleKeyDown);
      mainContent?.removeAttribute('inert');
      previousFocusRef.current?.focus(); // restore focus
    };
  }, [isOpen]);

  return containerRef;
}

Pattern 3: ARIA Live Regions for Dynamic Content

// Announce form errors, loading states, and updates to screen readers
function useAnnounce() {
  const announce = useCallback((message: string, priority: 'polite' | 'assertive' = 'polite') => {
    const el = document.getElementById(`aria-live-${priority}`);
    if (el) {
      el.textContent = '';  // Clear first to trigger re-announcement
      requestAnimationFrame(() => { el.textContent = message; });
    }
  }, []);

  return announce;
}

// Mount once in layout:
function AriaLiveRegions() {
  return (
    <>
      <div id="aria-live-polite" aria-live="polite" aria-atomic="true" className="sr-only" />
      <div id="aria-live-assertive" aria-live="assertive" aria-atomic="true" className="sr-only" />
    </>
  );
}

  ┌─ Accessibility Testing Pyramid ────────────────────┐
  │                                                     │
  │          ▲  Manual Screen Reader Testing            │
  │         ╱ ╲  (VoiceOver, NVDA — quarterly)         │
  │        ╱───╲                                        │
  │       ╱     ╲  Playwright + axe-core E2E           │
  │      ╱  E2E  ╲  (every page, CI gate)              │
  │     ╱─────────╲                                     │
  │    ╱           ╲  jest-axe Component Tests          │
  │   ╱  Component  ╲  (per interactive component)     │
  │  ╱───────────────╲                                  │
  │ ╱                 ╲  ESLint jsx-a11y                │
  │╱    Static Lint    ╲  (on every commit)             │
  │╲___________________╱                                │
  └─────────────────────────────────────────────────────┘

Anti-Patterns

1. div with onClick instead of button -- divs have no keyboard interaction, no role, and no focus. Use semantic <button> or <a> elements. If you must use a div, add role="button", tabindex="0", and onKeyDown for Enter/Space.
2. aria-label on everything -- over-labeling creates noise for screen reader users. Prefer visible text labels; use aria-label only when visible text is impossible.
3. Hiding focus outlines -- outline: none with no replacement makes keyboard navigation invisible. Use :focus-visible for keyboard-only focus indicators that do not appear on mouse click.
4. Missing skip navigation link -- keyboard users must tab through the entire nav on every page. Add <a href="#main" class="sr-only focus:not-sr-only">Skip to main content</a> as the first focusable element.
5. Toast notifications without live regions -- screen readers cannot detect dynamically added toasts. Use aria-live="polite" regions to announce them.

Quality Checklist

• axe-core CI gate passes with zero violations on all pages
• eslint-plugin-jsx-a11y enabled with no warnings
• All images have descriptive alt text (or alt="" for decorative images)
• All form inputs have associated <label> elements (not just placeholder text)
• Heading hierarchy is sequential (h1 > h2 > h3, no skipping)
• Page landmarks present: <main>, <nav>, <header>, <footer>
• Skip navigation link is the first focusable element
• Focus visible on all interactive elements (:focus-visible styles defined)
• Modals trap focus and restore focus on close
• Dynamic content changes announced via aria-live regions
• Color contrast ratios meet WCAG AA (4.5:1 normal text, 3:1 large text)
• All functionality operable with keyboard only (Tab, Enter, Space, Escape, Arrow keys)