Test Patterns & Best Practices Interview Questions

Key principles include: 1) Test isolation - each test should be independent, 2) Consistent selectors using data-* attributes, 3) Avoiding sleep/fixed waits, 4) Proper assertion usage, 5) Following the AAA (Arrange-Act-Assert) pattern, 6) Maintaining test readability, and 7) Implementing proper error handling.

Page Object Pattern encapsulates page elements and behaviors into classes/objects. In Cypress, it's implemented by creating classes/objects that contain selectors and methods for interacting with specific pages. This improves maintainability and reusability of test code.

Best practices include: 1) Using data-cy attributes for elements, 2) Avoiding brittle selectors like CSS classes or IDs that may change, 3) Following consistent naming conventions, 4) Using specific selectors over generic ones, 5) Maintaining a selector strategy guide for the team.

Tests should be structured with: 1) Clear describe blocks for feature groups, 2) Focused it blocks for specific behaviors, 3) Proper use of hooks for setup/cleanup, 4) Related tests grouped together, 5) Consistent file naming conventions, 6) Proper separation of concerns.

AAA pattern structures tests into three phases: 1) Arrange - set up test data and conditions, 2) Act - perform the action being tested, 3) Assert - verify the expected results. This pattern makes tests clear, maintainable, and follows a logical flow.

Test data should be: 1) Managed through fixtures or factories, 2) Isolated between tests, 3) Cleaned up after test execution, 4) Version controlled with tests, 5) Easily maintainable and updateable, 6) Environment-specific when needed.

Assertion best practices include: 1) Using explicit assertions over implicit ones, 2) Writing meaningful assertion messages, 3) Testing one thing per assertion, 4) Using appropriate assertion methods, 5) Implementing proper waiting strategies before assertions.

Authentication should be: 1) Implemented through API calls when possible, 2) Cached between tests when appropriate, 3) Properly cleaned up after tests, 4) Handled consistently across test suite, 5) Implemented with proper security considerations.

Custom commands should: 1) Be reusable across tests, 2) Follow consistent naming conventions, 3) Be well-documented, 4) Handle errors appropriately, 5) Be maintained in a central location, 6) Follow chainable patterns when appropriate.

Waiting strategies should: 1) Use Cypress's automatic waiting when possible, 2) Avoid arbitrary timeouts, 3) Wait for specific conditions or elements, 4) Use proper assertions for state changes, 5) Implement proper retry strategies.

Complex workflows should be: 1) Broken down into smaller, reusable steps, 2) Implemented using command chains or custom commands, 3) Properly documented, 4) Maintained with proper error handling, 5) Organized for maintainability.

Data-driven testing should: 1) Use external data sources or fixtures, 2) Implement proper data iteration strategies, 3) Handle data validation, 4) Maintain data independence between tests, 5) Include proper error handling for data scenarios.

State management should: 1) Maintain test isolation, 2) Handle state cleanup properly, 3) Use appropriate state management tools, 4) Implement proper state verification, 5) Consider state dependencies between tests.

Test hooks should: 1) Be used appropriately for setup/cleanup, 2) Maintain test independence, 3) Handle errors properly, 4) Be organized consistently, 5) Follow scope requirements, 6) Implement proper resource management.

Network request handling should: 1) Use proper stubbing strategies, 2) Implement appropriate waiting mechanisms, 3) Handle errors properly, 4) Maintain request isolation, 5) Include proper request verification.

Test retries should: 1) Be configured appropriately, 2) Handle flaky tests properly, 3) Include proper logging and reporting, 4) Maintain test integrity, 5) Consider performance implications.

Dynamic element handling should: 1) Use robust selection strategies, 2) Implement proper waiting mechanisms, 3) Handle state changes appropriately, 4) Include error handling, 5) Consider performance implications.

Test utilities should: 1) Be organized modularly, 2) Follow consistent patterns, 3) Be well-documented, 4) Include proper error handling, 5) Be maintained centrally, 6) Consider reusability across tests.

Test configuration should: 1) Be environment-aware, 2) Use proper configuration management, 3) Handle sensitive data appropriately, 4) Be maintainable and updateable, 5) Follow consistent patterns.

Error handling should: 1) Be comprehensive and consistent, 2) Include proper error reporting, 3) Handle different error types appropriately, 4) Maintain test stability, 5) Include proper recovery strategies.

Advanced organization includes: 1) Sophisticated test structuring, 2) Complex test workflow management, 3) Advanced pattern implementation, 4) Comprehensive documentation strategies, 5) Maintainable architecture patterns.

Advanced custom commands should: 1) Handle complex scenarios, 2) Implement sophisticated patterns, 3) Include comprehensive error handling, 4) Follow advanced design principles, 5) Consider performance optimization.

Complex state management should: 1) Handle sophisticated state scenarios, 2) Implement advanced state patterns, 3) Include comprehensive state verification, 4) Consider state optimization, 5) Handle complex state dependencies.

Advanced architectures should: 1) Handle complex testing requirements, 2) Implement sophisticated patterns, 3) Include comprehensive organization strategies, 4) Consider scalability and maintenance, 5) Follow advanced design principles.

Complex async handling should: 1) Manage sophisticated async scenarios, 2) Implement advanced waiting strategies, 3) Include comprehensive error handling, 4) Consider performance implications, 5) Handle complex timing issues.

Advanced data management should: 1) Handle complex data scenarios, 2) Implement sophisticated data patterns, 3) Include comprehensive data validation, 4) Consider data optimization, 5) Handle complex data dependencies.

Complex UI handling should: 1) Manage sophisticated interaction scenarios, 2) Implement advanced interaction patterns, 3) Include comprehensive verification strategies, 4) Consider performance optimization, 5) Handle complex UI states.