pedronauck/a11y-testing

Accessibility Testing

Automated accessibility testing with axe-core for WCAG 2.2 compliance. Catches 30-50% of issues automatically.

Overview

• Implementing CI/CD accessibility gates
• Running pre-release compliance audits
• Testing component accessibility in unit tests
• Validating page-level accessibility with E2E tests
• Ensuring keyboard navigation works correctly

Quick Reference

jest-axe Unit Testing

// jest.setup.ts
import { toHaveNoViolations } from 'jest-axe';
expect.extend(toHaveNoViolations);

// Button.test.tsx
import { render } from '@testing-library/react';
import { axe } from 'jest-axe';

it('has no a11y violations', async () => {
  const { container } = render(<Button>Click me</Button>);
  expect(await axe(container)).toHaveNoViolations();
});

Playwright + axe-core E2E

// e2e/accessibility.spec.ts
import { test, expect } from "@playwright/test";
import AxeBuilder from "@axe-core/playwright";

test("page has no a11y violations", async ({ page }) => {
  await page.goto("/");
  const results = await new AxeBuilder({ page })
    .withTags(["wcag2a", "wcag2aa", "wcag22aa"])
    .analyze();
  expect(results.violations).toEqual([]);
});

test("modal state has no violations", async ({ page }) => {
  await page.goto("/");
  await page.click('[data-testid="open-modal"]');
  await page.waitForSelector('[role="dialog"]');

  const results = await new AxeBuilder({ page })
    .include('[role="dialog"]')
    .withTags(["wcag2a", "wcag2aa"])
    .analyze();
  expect(results.violations).toEqual([]);
});

CI/CD Integration

# .github/workflows/accessibility.yml
name: Accessibility
on: [pull_request]

jobs:
  a11y:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: "20", cache: "npm" }
      - run: npm ci
      - run: npm run test:a11y
      - run: npm run build
      - run: npx playwright install --with-deps chromium
      - run: npm start & npx wait-on http://localhost:3000
      - run: npx playwright test e2e/accessibility

Key Decisions

| Decision | Choice | Rationale | | -------------- | --------------------------- | ----------------------------------- | | Test runner | jest-axe + Playwright | Unit + E2E coverage | | WCAG level | AA (wcag2aa) | Industry standard, legal compliance | | CI gate | Block on violations | Prevent regression | | Browser matrix | Chromium + Firefox | Cross-browser coverage | | Exclusions | Third-party widgets only | Minimize blind spots | | Tags | wcag2a, wcag2aa, wcag22aa | Full WCAG 2.2 AA | | State testing | Test all interactive states | Modal, error, loading |

Anti-Patterns (FORBIDDEN)

// BAD: Disabling rules globally
const results = await axe(container, {
  rules: { 'color-contrast': { enabled: false } }  // NEVER disable rules
});

// BAD: Excluding too much
new AxeBuilder({ page })
  .exclude('body')  // Defeats the purpose
  .analyze();

// BAD: Only testing happy path
it('form is accessible', async () => {
  const { container } = render(<Form />);
  expect(await axe(container)).toHaveNoViolations();
  // Missing: error state, loading state, disabled state
});

// BAD: No CI enforcement
// Accessibility tests exist but don't block PRs

// BAD: Manual-only testing
// Relying solely on human review - catches issues too late

Related Skills

• e2e-testing - Playwright E2E testing patterns
• unit-testing - Jest unit testing fundamentals
• design-system-starter - Accessible component foundations

Capability Details

jest-axe-testing

Keywords: jest, axe, unit test, component test, react-testing-library Solves:

• Component-level accessibility validation
• Fast feedback in development
• CI/CD unit test gates
• Testing all component states (disabled, error, loading)

playwright-axe-testing

Keywords: playwright, e2e, axe-core, page scan, wcag, integration Solves:

• Full page accessibility audits
• Testing interactive states (modals, menus, forms)
• Multi-browser accessibility verification
• WCAG compliance validation at page level

ci-a11y-gates

Keywords: ci, cd, github actions, accessibility gate, automation Solves:

• Blocking PRs with accessibility violations
• Automated regression prevention
• Compliance reporting and artifacts
• Integration with deployment pipelines