Interview Questions
Best practices include: 1) Mirror source code structure, 2) Use consistent naming conventions (.test.js, .spec.js), 3) Group related tests together, 4) Maintain test independence, 5) Keep test files focused and manageable, 6) Use descriptive file names.
describe blocks should: 1) Group related test cases, 2) Follow logical hierarchy, 3) Use clear, descriptive names, 4) Maintain proper nesting levels, 5) Share common setup when appropriate. Example: describe('User Authentication', () => { describe('Login', () => {});
Test descriptions should: 1) Be clear and specific, 2) Describe expected behavior, 3) Use consistent terminology, 4) Follow 'it should...' pattern, 5) Be readable as complete sentences. Example: it('should return error for invalid input')
Handle dependencies by: 1) Using before/beforeEach hooks, 2) Creating shared fixtures, 3) Implementing test helpers, 4) Managing shared state carefully, 5) Cleaning up after tests. Ensures test isolation.
Test hooks serve to: 1) Set up test prerequisites, 2) Clean up after tests, 3) Share common setup logic, 4) Manage test resources, 5) Maintain test isolation. Example: beforeEach(), afterEach() for setup/cleanup.
Test utilities should be: 1) Placed in separate helper files, 2) Grouped by functionality, 3) Made reusable across tests, 4) Well-documented, 5) Easy to maintain. Helps reduce code duplication.
Test fixtures: 1) Provide test data, 2) Set up test environment, 3) Ensure consistent test state, 4) Reduce setup duplication, 5) Make tests maintainable. Example: JSON files with test data.
Maintain independence by: 1) Cleaning up after each test, 2) Avoiding shared state, 3) Using fresh fixtures, 4) Isolating test environments, 5) Proper hook usage. Prevents test interference.
Common conventions: 1) .test.js suffix, 2) .spec.js suffix, 3) Match source file names, 4) Use descriptive prefixes, 5) Group related tests. Example: user.test.js for user.js tests.
Config management: 1) Use .mocharc.js file, 2) Separate environment configs, 3) Manage test timeouts, 4) Set reporter options, 5) Handle CLI arguments. Ensures consistent test execution.
Large app testing: 1) Organize by feature/module, 2) Use nested describes, 3) Share common utilities, 4) Implement proper separation, 5) Maintain clear structure. Improves maintainability.
Code sharing patterns: 1) Create helper modules, 2) Use shared fixtures, 3) Implement common utilities, 4) Create test base classes, 5) Use composition over inheritance. Reduces duplication.
Environment management: 1) Configure per environment, 2) Handle environment variables, 3) Set up test databases, 4) Manage external services, 5) Control test data. Ensures consistent testing.
Data management: 1) Use fixtures effectively, 2) Implement data factories, 3) Clean up test data, 4) Handle data dependencies, 5) Maintain data isolation. Ensures reliable tests.
Integration test organization: 1) Separate from unit tests, 2) Group by feature, 3) Handle dependencies properly, 4) Manage test order, 5) Control test environment. Ensures comprehensive testing.
Retry patterns: 1) Configure retry attempts, 2) Handle flaky tests, 3) Implement backoff strategy, 4) Log retry attempts, 5) Monitor retry patterns. Improves test reliability.
Cross-cutting concerns: 1) Implement test middleware, 2) Use global hooks, 3) Share common behavior, 4) Handle logging/monitoring, 5) Manage error handling. Ensures consistent behavior.
Documentation practices: 1) Write clear descriptions, 2) Document test setup, 3) Explain test rationale, 4) Maintain API docs, 5) Update documentation regularly. Improves test understanding.
Timeout management: 1) Set appropriate timeouts, 2) Configure per test/suite, 3) Handle async operations, 4) Monitor slow tests, 5) Implement timeout strategies. Ensures reliable execution.
Advanced patterns: 1) Custom test structures, 2) Complex test hierarchies, 3) Shared behavior specs, 4) Test composition, 5) Dynamic test generation. Enables sophisticated testing.
Microservice testing: 1) Service isolation, 2) Contract testing, 3) Integration patterns, 4) Service mocking, 5) Distributed testing. Important for service architecture.
Test monitoring: 1) Track execution metrics, 2) Monitor performance, 3) Log test data, 4) Analyze patterns, 5) Generate reports. Important for test maintenance.
Suite optimization: 1) Parallel execution, 2) Test grouping, 3) Resource management, 4) Cache utilization, 5) Performance tuning. Improves execution efficiency.
Complex dependencies: 1) Dependency injection, 2) Service locator pattern, 3) Mock factories, 4) State management, 5) Cleanup strategies. Important for large systems.
Data factory strategies: 1) Factory patterns, 2) Data generation, 3) State management, 4) Relationship handling, 5) Cleanup procedures. Important for test data management.
Test composition: 1) Shared behaviors, 2) Test mixins, 3) Behavior composition, 4) Context sharing, 5) State management. Enables reusable test patterns.
Distributed testing: 1) Service coordination, 2) State synchronization, 3) Resource management, 4) Error handling, 5) Result aggregation. Important for distributed systems.
Custom runners: 1) Runner implementation, 2) Test discovery, 3) Execution control, 4) Result reporting, 5) Configuration management. Enables specialized test execution.