qa-testing-playwright

# QA Testing (Playwright) High-signal, cost-aware E2E testing for web applications. Core docs: - https://playwright.dev/docs/best-practices - https://playwright.dev/docs/locators - https://playwright.dev/docs/test-retries - https://playwright.dev/docs/trace-viewer - https://playwright.dev/docs/test-sharding - https://playwright.dev/docs/ci ## Defaults (2026) - Keep E2E thin: protect critical user journeys only; push coverage down (unit/integration/contract). - Locator priority: `getByRole` → `getByLabel`/`getByText` → `getByTestId` (fallback). - Waiting: rely on Playwright auto-wait + web-first assertions; no sleeps/time-based waits. - Isolation: tests must run alone, in parallel, and in any order; eliminate shared mutable state. - Flake posture: retries are a debugging tool; treat rerun-pass as a failure signal and fix root cause. - CI posture: smoke gate on PRs; shard/parallelize regression on schedule; always keep artifacts (trace/video/screenshot). ## Quick Start | Command | Purpose | |---------|---------| | `npm init playwright@latest` | Initialize Playwright | | `npx playwright test` | Run all tests | | `npx playwright test --grep @smoke` | Run smoke tests | | `npx playwright test --project=chromium` | Run a single project | | `npx playwright test --ui` | Debug with UI mode | | `npx playwright test --debug` | Step through a test | | `npx playwright show-trace trace.zip` | Inspect trace artifacts | | `npx playwright show-report` | Inspect HTML report | ## When to ...