Accessibility testing is a form of automated and manual testing that helps us identify some of the potential accessibility concerns on Forem. See also, the Forem Frontend Accessibility docs.
Many accessibility (a11y) issues are not obvious to everyone who contributes to the Forem project, therefore leaning on tools to help us identify these issues is a good practice.
It's a good idea to use browser plugins while you're developing to keep an eye out for these issues, as well as including automated tests to catch regressions in future changes.
The axe devtools extension is a great place to get started. It works in both Firefox and Chrome. Use an extension like this one to find potential a11y issues in your workflow.
Automated testing in Preact
An overarching a11y testing strategy isn't currently in place for the Forem application, but there are some automated tools you can take advantage of in this project.
It is important to note that automated accessibility testing is only effective at finding ~30% of accessibility issues. It's important to do manual a11y testing as well.
When you're writing Preact components, you can include some basic a11y testing in your unit tests with jest-axe.
If you're still curious there are some great talks on accessibility for developers.
PR Review Checklist
Pull Requests should include accessibility testing to prevent barriers from making it into the codebase. Sometimes issues found may be out of scope for a particular PR – those can be opened as separate issues to be followed up on.
Test the functionality in Forem-supported browsers for accessibility impact: Chrome and Firefox were popular for Windows screen reader users in 2019 according to WebAIM. Safari is the most common choice for Voiceover users on the Mac, even if Chrome is widely used for development. Mobile browsers are worth checking, too.
- Keyboard: navigate the page without using a mouse or trackpad.
- Can you reach and operate the interactive controls like menus, buttons, and other widgets?
- Can you see your focus point on the screen, and does the focus style have adequate contrast?
- Does your focus point get lost or hidden behind any layers with items needing to be disabled/hidden?
- Run a browser extension.
- Test color contrast.
Additional accessibility tests for PR reviews
- Screen reader testing
- Get feedback from people who use screen readers regularly if at all possible.
- Understand that if you're a new screen reader user, there might be a learning curve that can impact your results.
- Navigate through a UI change using a screen reader such as Mac Voiceover with Safari, and NVDA with Firefox or Chrome on Windows.
- Zoom and magnification
- In the web browser, try zooming in from 200% to 500%.
- Would the layout or change of functionality be impacted by someone needing to magnify their screen? Are there alternative styling or other solutions that would make zooming any easier?