Accessibility rules engine

An accessibility rules engine applies automated rules, most of them from WCAG, to a page the browser has rendered, and names the element behind each violation. It catches what a rule can express, which is only part of what a person using assistive technology would meet.

Finding it

Look in the dev dependencies for the engine or its package for the project's browser driver, and in the browser tests for the call that runs it. Its settings (the rule tags it applies, the rules or regions it leaves out) sit beside that call.

Using it

• Run it inside the browser tests, on each page or state worth checking (@axe-core/playwright for Playwright; other drivers have their own package).
• Apply the level the project commits to, for example the wcag2a and wcag2aa tags, and keep every exclusion with its reason.
• Keep the selector: each violation comes back with its rule, its impact and a selector for the element; report all three.
• Snapshot the accessibility tree of key pages (toMatchAriaSnapshot in Playwright), so a lost role or name shows as a diff.

Examples: axe-core (inside Playwright or other drivers), accessibility-tree snapshots.