Web accessibility is crucial to ensure that websites and web applications can be used by everyone, including those with disabilities. In this chapter, we will learn how to use Mocha to perform automated accessibility testing.

Tools for Accessibility Testing

To perform accessibility tests with Mocha, we will use a combination of axe-core, a powerful tool for accessibility analysis, and jsdom, to simulate a browser environment.

Installing axe-core and jsdom

First, we need to install axe-core and jsdom. You can do this by running the following commands:

sh

Setting Up Accessibility Tests

Sample Application

Suppose we have a simple HTML application:

html

Writing the Accessibility Test

Create a test file called accessibility.test.js:

javascript

Running the Test

Run the test using npm test and you should see an output indicating that the test has passed if there are no accessibility violations.

sh

Accessibility Testing with Dynamic Content

If your web application can dynamically modify content, you can also perform accessibility tests after these changes.

Application with Dynamic Content

Suppose we have the following JavaScript functionality:

html

javascript

Writing the Accessibility Test for Dynamic Content

javascript

Analyzing and Reporting Results

Running the tests will identify any accessibility violations. If any are found, you can use the report output to identify and fix the issues.

Improving Accessibility in External Resources

If your application loads external resources or third-party libraries, it's important to include these resources in the accessibility tests. This can be done by loading the resources in the jsdom context and then running the tests.

Conclusion

Performing accessibility tests is an integral part of modern web development. Ensuring that your website is accessible to all users not only improves user experience but is also an ethical and legal responsibility. With Mocha, jsdom, and axe-core, you can automate and simplify this testing process.

In the next chapter, we will look at handling asynchronous tests with Mocha for more complex testing scenarios.