Automated Accessibility Testing

Automated accessibility testing runs programmatic checks for accessibility issues, catching problems early in development and preventing regressions. Integration with CI/CD pipelines makes accessibility part of the standard development workflow.

What Is Automated Accessibility Testing

Automated accessibility testing uses software to check for accessibility issues that can be detected programmatically. This includes missing alt text, insufficient contrast, improper heading hierarchy, missing form labels, and many ARIA issues.

Benefits of automation include:

• Consistent checking on every build
• Early detection before issues reach production
• Documented baseline of accessibility status
• Reduced manual testing burden
• Regression prevention

Limitations exist: automated tools catch approximately 30-40% of accessibility issues. Manual testing remains necessary for issues requiring human judgment.

How Automated Accessibility Testing Works

Testing libraries like axe-core provide engines for automated checks. These integrate with testing frameworks:

Jest integration runs accessibility checks as part of unit or integration tests. Failures appear alongside other test failures:

CI/CD integration runs accessibility checks on every commit or pull request. Configuration determines whether issues block merges or generate warnings:

Coverage configuration determines which rules run. Most tools support filtering by WCAG level (A, AA, AAA), tags, or specific rules. Design systems typically configure for WCAG AA minimum.

Reporting generates documentation of accessibility status. Test results show which rules pass, fail, or need review. Trend tracking reveals whether accessibility is improving or degrading.

Key Considerations

• Integrate accessibility tests in CI/CD pipelines
• Configure tests for your target WCAG level
• Run tests on rendered components, not just static code
• Fail builds on accessibility violations
• Track accessibility metrics over time
• Supplement automated tests with manual testing
• Document testing configuration for contributors

Common Questions

Should accessibility tests block builds?

Yes, accessibility tests should block builds like other test failures. Treating accessibility issues as optional leads to accumulating debt. If an issue is serious enough to detect, it is serious enough to fix before merging.

Exceptions may be made for known issues being actively addressed, but these should be explicitly documented and time-limited.

How should flaky accessibility tests be handled?

Accessibility tests can be flaky if components render inconsistently or timing issues occur. Address flakiness through:

• Waiting for components to fully render before testing
• Testing in consistent, controlled environments
• Isolating component tests from external dependencies
• Investigating and fixing underlying timing issues

Do not simply ignore flaky accessibility tests, as this masks real issues.

What about testing components in isolation versus composition?

Both matter. Component-level testing verifies individual elements are accessible. Composition testing verifies that accessible components work together accessibly (heading hierarchy, landmark structure, focus order).

Design systems particularly benefit from component-level testing since components are the reusable building blocks. Application testing then verifies proper composition.

Summary

Automated accessibility testing integrates programmatic accessibility checks into development workflows through CI/CD pipelines and testing frameworks. While automated tests catch only a portion of accessibility issues, they provide consistent checking, regression prevention, and documented accessibility status.