Testing
There are a number of testing libraries that can be used to test for accessibility issues, including:
@axe-core/playwright(opens in a new tab) - for pass/fail testing in UI/E2E testsjest-axe(opens in a new tab) - for pass/fail testing at a component level in jsx@axe-core/react(opens in a new tab) - for live developer testing in dev tools
These tools can be incorporated into normal pipelines, or run at separate times, to ensure that the accessibility of the site is maintained.
While these will only be identifying the automated issues, they can be used to ensure that the site is at least at a basic level of accessibility.