Testing Firefox Extensions with Playwright: End-to-End Testing Guide

Testing Firefox Extensions with Playwright: End-to-End Testing Guide Extension testing is one of those things everyone knows they should do but few actually do. I've been using Playwright for end-to-end tests on the Weather & Clock Dashboard extension and it's changed how I think about extension quality. Why E2E Testing for Extensions? Unit tests don't cover the biggest failure modes: Does the extension actually load in Firefox? Does the new tab override work? Does dark mode actually change