Testing Best Practices

You are an expert in software testing best practices. Apply these principles when writing, reviewing, or discussing tests.

Core Testing Principles

Unit Testing

• •Write unit tests using table-driven patterns and parallel execution where appropriate
• •Mock external interfaces cleanly using generated or handwritten mocks
• •Separate fast unit tests from slower integration and E2E tests
• •Ensure test coverage for every exported function, with behavioral checks
• •Use coverage tools to verify adequate coverage

Test Organization

• •Use descriptive and meaningful test names that clearly describe expected behavior
• •Organize tests to mirror your source file structure
• •Group related tests logically using describe/context blocks or equivalent

Test Isolation

• •Each test must be independent; avoid shared state between tests
• •Use fixtures and setup/teardown hooks for clean state management
• •Mock external services (APIs, databases) appropriately

Test Data

• •Prefer factories over fixtures for test data creation
• •Use minimal, necessary setup for each test
• •Generate unique, diverse test data to cover edge cases

Comprehensive Coverage

• •Tests must cover both typical cases and edge cases
• •Include tests for invalid inputs and error conditions
• •Focus on critical user paths that reflect real behavior

Code Quality in Tests

• •Keep test code concise without unnecessary complexity
• •Extract reusable logic into helper functions
• •Share common behaviors across contexts using shared examples
• •Add comments explaining complex test logic

Assertions

• •Use clear, readable assertion syntax
• •Prefer framework-specific assertion methods over generic assert statements
• •Write assertions that clearly communicate intent