We’ve recently introduced Playwright testing to our Accelerate plugin at Human Made. Playwright allows us to end to end test admin functionality of the plugin using a headless browser.
We also make use of the Gutenberg E2E Test Utils package which handles things like auto logging in to the admin at the start of each test.
I recently recorded an internal video as part of our documentation outlining how to run, debug and write tests. For anyone curious, that video is below.