--- name: playwright-best-practices description: Use when writing Playwright tests, fixing flaky tests, debugging failures, implementing Page Object Model, configuring CI/CD, optimizing performance, mocking APIs, handling authentication or OAuth, testing accessibility (axe-core), file uploads/downloads, date/time mocking, WebSockets, geolocation, permissions, multi-tab/popup flows, mobile/responsive layouts, touch gestures, GraphQL, error handling, offline mode, multi-user collaboration, third-party services (payments, email verification), console error monitoring, global setup/teardown, test annotations (skip, fixme, slow), test tags (@smoke, @fast, @critical, filtering with --grep), project dependencies, security testing (XSS, CSRF, auth), performance budgets (Web Vitals, Lighthouse), iframes, component testing, canvas/WebGL, service workers/PWA, test coverage, i18n/localization, Electron apps, or browser extension testing. Covers E2E, component, API, visual, accessibility, security, Electron, and extension testing. license: MIT metadata: author: currents.dev version: "1.1" --- # Playwright Best Practices This skill provides comprehensive guidance for all aspects of Playwright test development, from writing new tests to debugging and maintaining existing test suites. ## Activity-Based Reference Guide Consult these references based on what you're doing: ### Writing New Tests **When to use**: Creating new test files, writing test cases, implementing test scenarios | Activity | Reference Files | | ----------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | | **Writing E2E tests** | [test-suite-structure.md](core/test-suite-structure.md), [locators.md](core/locators.md), [assertions-waiting.md](core/assertions-waiting.md) | | **Writing component tests** | [component-testing.md](testing-patterns/component-testing.md), [test-suite-structure.md](core/test-suite-structure.md) | | **Writing API tests** | [api-testing.md](testing-patterns/api-testing.md), [test-suite-structure.md](core/test-suite-structure.md) | | **Writing GraphQL tests** | [graphql-testing.md](testing-patterns/graphql-testing.md), [api-testing.md](testing-patterns/api-testing.md) | | **Writing visual regression tests** | [visual-regression.md](testing-patterns/visual-regression.md), [canvas-webgl.md](testing-patterns/canvas-webgl.md) | | **Structuring test code with POM** | [page-object-model.md](core/page-object-model.md), [test-suite-structure.md](core/test-suite-structure.md) | | **Setting up test data/fixtures** | [fixtures-hooks.md](core/fixtures-hooks.md), [test-data.md](core/test-data.md) | | **Handling authentication** | [authentication.md](advanced/authentication.md), [authentication-flows.md](advanced/authentication-flows.md) | | **Testing date/time features** | [clock-mocking.md](advanced/clock-mocking.md) | | **Testing file upload/download** | [file-operations.md](testing-patterns/file-operations.md), [file-upload-download.md](testing-patterns/file-upload-download.md) | | **Testing forms/validation** | [forms-validation.md](testing-patterns/forms-validation.md) | | **Testing drag and drop** | [drag-drop.md](testing-patterns/drag-drop.md) | | **Testing accessibility** | [accessibility.md](testing-patterns/accessibility.md) | | **Testing security (XSS, CSRF)** | [security-testing.md](testing-patterns/security-testing.md) | | **Using test annotations** | [annotations.md](core/annotations.md) | | **Using test tags** | [test-tags.md](core/test-tags.md) | | **Testing iframes** | [iframes.md](browser-apis/iframes.md) | | **Testing canvas/WebGL** | [canvas-webgl.md](testing-patterns/canvas-webgl.md) | | **Internationalization (i18n)** | [i18n.md](testing-patterns/i18n.md) | | **Testing Electron apps** | [electron.md](testing-patterns/electron.md) | | **Testing browser extensions** | [browser-extensions.md](testing-patterns/browser-extensions.md) | ### Mobile & Responsive Testing **When to use**: Testing mobile devices, touch interactions, responsive layouts | Activity | Reference Files | | ------------------------------- | -------------------------------------------------------------------------------- | | **Device emulation** | [mobile-testing.md](advanced/mobile-testing.md) | | **Touch gestures (swipe, tap)** | [mobile-testing.md](advanced/mobile-testing.md) | | **Viewport/breakpoint testing** | [mobile-testing.md](advanced/mobile-testing.md) | | **Mobile-specific UI** | [mobile-testing.md](advanced/mobile-testing.md), [locators.md](core/locators.md) | ### Real-Time & Browser APIs **When to use**: Testing WebSockets, geolocation, permissions, multi-tab flows | Activity | Reference Files | | ------------------------------- | ---------------------------------------------------------------------------------------- | | **WebSocket/real-time testing** | [websockets.md](browser-apis/websockets.md) | | **Geolocation mocking** | [browser-apis.md](browser-apis/browser-apis.md) | | **Permission handling** | [browser-apis.md](browser-apis/browser-apis.md) | | **Clipboard testing** | [browser-apis.md](browser-apis/browser-apis.md) | | **Camera/microphone mocking** | [browser-apis.md](browser-apis/browser-apis.md) | | **Multi-tab/popup flows** | [multi-context.md](advanced/multi-context.md) | | **OAuth popup handling** | [third-party.md](advanced/third-party.md), [multi-context.md](advanced/multi-context.md) | ### Debugging & Troubleshooting **When to use**: Test failures, element not found, timeouts, unexpected behavior | Activity | Reference Files | | ------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | **Debugging test failures** | [debugging.md](debugging/debugging.md), [assertions-waiting.md](core/assertions-waiting.md) | | **Fixing flaky tests** | [flaky-tests.md](debugging/flaky-tests.md), [debugging.md](debugging/debugging.md), [assertions-waiting.md](core/assertions-waiting.md) | | **Debugging flaky parallel runs** | [flaky-tests.md](debugging/flaky-tests.md), [performance.md](infrastructure-ci-cd/performance.md), [fixtures-hooks.md](core/fixtures-hooks.md) | | **Ensuring test isolation / avoiding state leak** | [flaky-tests.md](debugging/flaky-tests.md), [fixtures-hooks.md](core/fixtures-hooks.md), [performance.md](infrastructure-ci-cd/performance.md) | | **Fixing selector issues** | [locators.md](core/locators.md), [debugging.md](debugging/debugging.md) | | **Investigating timeout issues** | [assertions-waiting.md](core/assertions-waiting.md), [debugging.md](debugging/debugging.md) | | **Using trace viewer** | [debugging.md](debugging/debugging.md) | | **Debugging race conditions** | [flaky-tests.md](debugging/flaky-tests.md), [debugging.md](debugging/debugging.md), [assertions-waiting.md](core/assertions-waiting.md) | | **Debugging console/JS errors** | [console-errors.md](debugging/console-errors.md), [debugging.md](debugging/debugging.md) | ### Error & Edge Case Testing **When to use**: Testing error states, offline mode, network failures, validation | Activity | Reference Files | | ------------------------------ | ----------------------------------------------------------------------------------------------------- | | **Error boundary testing** | [error-testing.md](debugging/error-testing.md) | | **Network failure simulation** | [error-testing.md](debugging/error-testing.md), [network-advanced.md](advanced/network-advanced.md) | | **Offline mode testing** | [error-testing.md](debugging/error-testing.md), [service-workers.md](browser-apis/service-workers.md) | | **Service worker testing** | [service-workers.md](browser-apis/service-workers.md) | | **Loading state testing** | [error-testing.md](debugging/error-testing.md) | | **Form validation testing** | [error-testing.md](debugging/error-testing.md) | ### Multi-User & Collaboration Testing **When to use**: Testing features involving multiple users, roles, or real-time collaboration | Activity | Reference Files | | ------------------------------ | ------------------------------------------------------------------------------------ | | **Multiple users in one test** | [multi-user.md](advanced/multi-user.md) | | **Real-time collaboration** | [multi-user.md](advanced/multi-user.md), [websockets.md](browser-apis/websockets.md) | | **Role-based access testing** | [multi-user.md](advanced/multi-user.md) | | **Concurrent action testing** | [multi-user.md](advanced/multi-user.md) | ### Architecture Decisions **When to use**: Choosing test patterns, deciding between approaches, planning test architecture | Activity | Reference Files | | ---------------------------- | --------------------------------------------------------- | | **POM vs fixtures decision** | [pom-vs-fixtures.md](architecture/pom-vs-fixtures.md) | | **Test type selection** | [test-architecture.md](architecture/test-architecture.md) | | **Mock vs real services** | [when-to-mock.md](architecture/when-to-mock.md) | | **Test suite structure** | [test-suite-structure.md](core/test-suite-structure.md) | ### Framework-Specific Testing **When to use**: Testing React, Angular, Vue, or Next.js applications | Activity | Reference Files | | ------------------------- | ----------------------------------- | | **Testing React apps** | [react.md](frameworks/react.md) | | **Testing Angular apps** | [angular.md](frameworks/angular.md) | | **Testing Vue/Nuxt apps** | [vue.md](frameworks/vue.md) | | **Testing Next.js apps** | [nextjs.md](frameworks/nextjs.md) | ### Refactoring & Maintenance **When to use**: Improving existing tests, code review, reducing duplication | Activity | Reference Files | | ------------------------------------ | ---------------------------------------------------------------------------------------------------------- | | **Refactoring to Page Object Model** | [page-object-model.md](core/page-object-model.md), [test-suite-structure.md](core/test-suite-structure.md) | | **Improving test organization** | [test-suite-structure.md](core/test-suite-structure.md), [page-object-model.md](core/page-object-model.md) | | **Extracting common setup/teardown** | [fixtures-hooks.md](core/fixtures-hooks.md) | | **Replacing brittle selectors** | [locators.md](core/locators.md) | | **Removing explicit waits** | [assertions-waiting.md](core/assertions-waiting.md) | | **Creating test data factories** | [test-data.md](core/test-data.md) | | **Configuration setup** | [configuration.md](core/configuration.md) | ### Infrastructure & Configuration **When to use**: Setting up projects, configuring CI/CD, optimizing performance | Activity | Reference Files | | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | **Configuring Playwright project** | [configuration.md](core/configuration.md), [projects-dependencies.md](core/projects-dependencies.md) | | **Setting up CI/CD pipelines** | [ci-cd.md](infrastructure-ci-cd/ci-cd.md), [github-actions.md](infrastructure-ci-cd/github-actions.md) | | **GitHub Actions setup** | [github-actions.md](infrastructure-ci-cd/github-actions.md) | | **GitLab CI setup** | [gitlab.md](infrastructure-ci-cd/gitlab.md) | | **Other CI providers** | [other-providers.md](infrastructure-ci-cd/other-providers.md) | | **Docker/container setup** | [docker.md](infrastructure-ci-cd/docker.md) | | **Global setup & teardown** | [global-setup.md](core/global-setup.md) | | **Project dependencies** | [projects-dependencies.md](core/projects-dependencies.md) | | **Optimizing test performance** | [performance.md](infrastructure-ci-cd/performance.md), [test-suite-structure.md](core/test-suite-structure.md) | | **Configuring parallel execution** | [parallel-sharding.md](infrastructure-ci-cd/parallel-sharding.md), [performance.md](infrastructure-ci-cd/performance.md) | | **Isolating test data between workers** | [fixtures-hooks.md](core/fixtures-hooks.md), [performance.md](infrastructure-ci-cd/performance.md) | | **Test coverage** | [test-coverage.md](infrastructure-ci-cd/test-coverage.md) | | **Test reporting/artifacts** | [reporting.md](infrastructure-ci-cd/reporting.md) | ### Advanced Patterns **When to use**: Complex scenarios, API mocking, network interception | Activity | Reference Files | | ------------------------------------ | ------------------------------------------------------------------------------------------------------------ | | **Mocking API responses** | [test-suite-structure.md](core/test-suite-structure.md), [network-advanced.md](advanced/network-advanced.md) | | **Network interception** | [network-advanced.md](advanced/network-advanced.md), [assertions-waiting.md](core/assertions-waiting.md) | | **GraphQL mocking** | [network-advanced.md](advanced/network-advanced.md) | | **HAR recording/playback** | [network-advanced.md](advanced/network-advanced.md) | | **Custom fixtures** | [fixtures-hooks.md](core/fixtures-hooks.md) | | **Advanced waiting strategies** | [assertions-waiting.md](core/assertions-waiting.md) | | **OAuth/SSO mocking** | [third-party.md](advanced/third-party.md), [multi-context.md](advanced/multi-context.md) | | **Payment gateway mocking** | [third-party.md](advanced/third-party.md) | | **Email/SMS verification mocking** | [third-party.md](advanced/third-party.md) | | **Failing on console errors** | [console-errors.md](debugging/console-errors.md) | | **Security testing (XSS, CSRF)** | [security-testing.md](testing-patterns/security-testing.md) | | **Performance budgets & Web Vitals** | [performance-testing.md](testing-patterns/performance-testing.md) | | **Lighthouse integration** | [performance-testing.md](testing-patterns/performance-testing.md) | | **Test annotations (skip, fixme)** | [annotations.md](core/annotations.md) | | **Test tags (@smoke, @fast)** | [test-tags.md](core/test-tags.md) | | **Test steps for reporting** | [annotations.md](core/annotations.md) | ## Quick Decision Tree ```text What are you doing? │ ├─ Writing a new test? │ ├─ E2E test → core/test-suite-structure.md, core/locators.md, core/assertions-waiting.md │ ├─ Component test → testing-patterns/component-testing.md │ ├─ API test → testing-patterns/api-testing.md, core/test-suite-structure.md │ ├─ GraphQL test → testing-patterns/graphql-testing.md │ ├─ Visual regression → testing-patterns/visual-regression.md │ ├─ Visual/canvas test → testing-patterns/canvas-webgl.md, core/test-suite-structure.md │ ├─ Accessibility test → testing-patterns/accessibility.md │ ├─ Mobile/responsive test → advanced/mobile-testing.md │ ├─ i18n/locale test → testing-patterns/i18n.md │ ├─ Electron app test → testing-patterns/electron.md │ ├─ Browser extension test → testing-patterns/browser-extensions.md │ ├─ Multi-user test → advanced/multi-user.md │ ├─ Form validation test → testing-patterns/forms-validation.md │ └─ Drag and drop test → testing-patterns/drag-drop.md │ ├─ Testing specific features? │ ├─ File upload/download → testing-patterns/file-operations.md, testing-patterns/file-upload-download.md │ ├─ Date/time dependent → advanced/clock-mocking.md │ ├─ WebSocket/real-time → browser-apis/websockets.md │ ├─ Geolocation/permissions → browser-apis/browser-apis.md │ ├─ OAuth/SSO mocking → advanced/third-party.md, advanced/multi-context.md │ ├─ Payments/email/SMS → advanced/third-party.md │ ├─ iFrames → browser-apis/iframes.md │ ├─ Canvas/WebGL/charts → testing-patterns/canvas-webgl.md │ ├─ Service workers/PWA → browser-apis/service-workers.md │ ├─ i18n/localization → testing-patterns/i18n.md │ ├─ Security (XSS, CSRF) → testing-patterns/security-testing.md │ └─ Performance/Web Vitals → testing-patterns/performance-testing.md │ ├─ Architecture decisions? │ ├─ POM vs fixtures → architecture/pom-vs-fixtures.md │ ├─ Test type selection → architecture/test-architecture.md │ ├─ Mock vs real services → architecture/when-to-mock.md │ └─ Test suite structure → core/test-suite-structure.md │ ├─ Framework-specific testing? │ ├─ React app → frameworks/react.md │ ├─ Angular app → frameworks/angular.md │ ├─ Vue/Nuxt app → frameworks/vue.md │ └─ Next.js app → frameworks/nextjs.md │ ├─ Authentication testing? │ ├─ Basic auth patterns → advanced/authentication.md │ └─ Complex flows (MFA, reset) → advanced/authentication-flows.md │ ├─ Test is failing/flaky? │ ├─ Flaky test investigation → debugging/flaky-tests.md │ ├─ Element not found → core/locators.md, debugging/debugging.md │ ├─ Timeout issues → core/assertions-waiting.md, debugging/debugging.md │ ├─ Race conditions → debugging/flaky-tests.md, debugging/debugging.md │ ├─ Flaky only with multiple workers → debugging/flaky-tests.md, infrastructure-ci-cd/performance.md │ ├─ State leak / isolation → debugging/flaky-tests.md, core/fixtures-hooks.md │ ├─ Console/JS errors → debugging/console-errors.md, debugging/debugging.md │ └─ General debugging → debugging/debugging.md │ ├─ Testing error scenarios? │ ├─ Network failures → debugging/error-testing.md, advanced/network-advanced.md │ ├─ Offline (unexpected) → debugging/error-testing.md │ ├─ Offline-first/PWA → browser-apis/service-workers.md │ ├─ Error boundaries → debugging/error-testing.md │ └─ Form validation → testing-patterns/forms-validation.md, debugging/error-testing.md │ ├─ Refactoring existing code? │ ├─ Implementing POM → core/page-object-model.md │ ├─ Improving selectors → core/locators.md │ ├─ Extracting fixtures → core/fixtures-hooks.md │ ├─ Creating data factories → core/test-data.md │ └─ Configuration setup → core/configuration.md │ ├─ Setting up infrastructure? │ ├─ CI/CD → infrastructure-ci-cd/ci-cd.md │ ├─ GitHub Actions → infrastructure-ci-cd/github-actions.md │ ├─ GitLab CI → infrastructure-ci-cd/gitlab.md │ ├─ Other CI providers → infrastructure-ci-cd/other-providers.md │ ├─ Docker/containers → infrastructure-ci-cd/docker.md │ ├─ Sharding/parallel → infrastructure-ci-cd/parallel-sharding.md │ ├─ Reporting/artifacts → infrastructure-ci-cd/reporting.md │ ├─ Global setup/teardown → core/global-setup.md │ ├─ Project dependencies → core/projects-dependencies.md │ ├─ Test performance → infrastructure-ci-cd/performance.md │ ├─ Test coverage → infrastructure-ci-cd/test-coverage.md │ └─ Project config → core/configuration.md, core/projects-dependencies.md │ ├─ Organizing tests? │ ├─ Skip/fixme/slow tests → core/annotations.md │ ├─ Test tags (@smoke, @fast) → core/test-tags.md │ ├─ Filtering tests (--grep) → core/test-tags.md │ ├─ Test steps → core/annotations.md │ └─ Conditional execution → core/annotations.md │ └─ Running subset of tests? ├─ By tag (@smoke, @critical) → core/test-tags.md ├─ Exclude slow/flaky tests → core/test-tags.md ├─ PR vs nightly tests → core/test-tags.md, infrastructure-ci-cd/ci-cd.md └─ Project-specific filtering → core/test-tags.md, core/configuration.md ``` ## Test Validation Loop After writing or modifying tests: 1. **Run tests**: `pytest -v` 2. **If tests fail**: - Review error output and trace (`playwright show-trace`) - Fix locators, waits, or assertions - Re-run tests 3. **Only proceed when all tests pass** 4. **Run multiple times** for critical tests: `pytest --count=5` (with pytest-repeat)