Playwright E2E Testing for Next.js: Auth Setup, Stripe Checkout, and CI Integration

Unit tests catch logic bugs. E2E tests catch the bugs that actually kill your conversion rate -- the broken checkout flow, the login redirect loop, the payment form that silently fails. Here's a practical Playwright setup for Next.js focused on critical paths. Setup npm install -D @playwright/test npx playwright install chromium // playwright.config.ts import { defineConfig } from ' @playwright/test ' export default defineConfig ({ testDir : ' ./e2e ' , fullyParallel : true , retries : process . env . CI ? 2 : 0 , reporter : ' html ' , use : { baseURL : ' http://localhost:3000 ' , trace : ' on-first-retry ' , screenshot : ' only-on-failure ' }, webServer : { command : ' npm run dev ' , url : ' http://localhost:3000 ' , reuseExistingServer : ! process . env . CI }, projects : [ { name : ' setup ' , testMatch : /global.setup \. ts/ }, { name : ' chromium ' , use : { storageState : ' e2e/.auth/user.json ' }, dependencies : [ ' setup ' ] } ] }) Auth Setup (Sign In Once, Use Everywhere) //