Building Accessible UI Components with Storybook
The Importance of Accessibility in Component Libraries
When building a component library, accessibility is often overlooked as a “nice-to-have” feature. However, it’s essential to prioritize accessibility to ensure that our applications are usable by everyone. Introducing accessibility practices can be challenging, but with the right tools, it can be made easier.
Introducing Storybook’s Accessibility Add-on
Storybook is a popular open-source project that helps teams develop consistent UI components. Its accessibility add-on provides support for automated accessibility tests, allowing us to capture and surface accessibility errors early in the development process. This add-on runs the deque axe accessibility testing tool on each Story, providing a panel to visualize axe’s test results within each Story’s UI.
Getting Started with the Accessibility Add-on
To get started, we need to install Storybook and the accessibility add-on in our React application. We’ll also need to create a main.js file inside the.storybook folder with the necessary configuration.
Testing Our Component
Let’s take a look at an example of a top navigation component. At first glance, the component looks ready to ship, but when we run the accessibility tests, we discover four violations. The accessibility add-on provides a Highlight results checkbox that helps identify the components that are failing, saving us time and effort.
Common Accessibility Issues
The accessibility add-on detects several common accessibility issues, including:
- Missing discernible text on buttons
- Insufficient contrast ratio between links and text
- Missing alt attributes on images
- Incorrect use of semantic HTML elements
Configuring axe to Your Needs
The accessibility add-on respects axe’s rule-based system, allowing us to configure the accessibility violations depending on our needs. We can override certain rules on the Story level using parameters.a11y.config.rules.
Automating Accessibility Tests
We can automate accessibility tests using Storybook with testing frameworks like Jest or React Testing Library. The Jest Axe integration introduces an axe-matcher into Jest, allowing us to automate the search for violations.
Conclusion
While automated accessibility tests are essential, they shouldn’t replace manual testing with assistive technologies and user research. It’s exciting to see the increasing effort to introduce developer tools that contribute to building accessible UI. By prioritizing accessibility, we can create better digital experiences for everyone.