e2e-testing-patterns

# E2E Testing Patterns Build reliable, fast, and maintainable end-to-end test suites that provide confidence to ship code quickly and catch regressions before users do. ## When to Use This Skill - Implementing end-to-end test automation - Debugging flaky or unreliable tests - Testing critical user workflows - Setting up CI/CD test pipelines - Testing across multiple browsers - Validating accessibility requirements - Testing responsive designs - Establishing E2E testing standards ## Core Concepts ### 1. E2E Testing Fundamentals **What to Test with E2E:** - Critical user journeys (login, checkout, signup) - Complex interactions (drag-and-drop, multi-step forms) - Cross-browser compatibility - Real API integration - Authentication flows **What NOT to Test with E2E:** - Unit-level logic (use unit tests) - API contracts (use integration tests) - Edge cases (too slow) - Internal implementation details ### 2. Test Philosophy **The Testing Pyramid:** ``` /\ /E2E\ ← Few, focused on critical paths /─────\ /Integr\ ← More, test component interactions /────────\ /Unit Tests\ ← Many, fast, isolated /────────────\ ``` **Best Practices:** - Test user behavior, not implementation - Keep tests independent - Make tests deterministic - Optimize for speed - Use data-testid, not CSS selectors ## Playwright Patterns ### Setup and Configuration ```typescript // playwright.config.ts import { defineConfig, devices } from "@playwr...