Code Testing Best Practices

Test Structure & Organization

• Write descriptive test names that clearly explain what is being tested
• Follow the AAA pattern: Arrange, Act, Assert
• Group related tests together in logical test suites
• Keep tests independent - each test should be able to run in isolation

Test Coverage & Scope

• Write tests for both happy path and edge cases
• Include tests for error conditions and invalid inputs
• Test boundary conditions (empty strings, null values, maximum/minimum values)
• All tests should have at least one assertion. Always use assertions instead of console logging to validate test results.
• Aim for meaningful coverage, not just high percentage coverage

Test Quality

• Keep tests simple and focused - test one thing at a time
• Make tests deterministic - avoid randomness or time-dependent behavior
• Use clear, descriptive assertions with helpful error messages
• Avoid testing implementation details; focus on behavior and outcomes

Test Data & Setup

• Use minimal test data that clearly demonstrates the test case
• Create reusable test fixtures and helper functions for common setup
• Clean up resources after tests (database records, files, network connections)
• Use test doubles (mocks, stubs, fakes) to isolate units under test

Performance & Maintenance

• Keep tests fast - slow tests discourage frequent running
• Make tests easy to read and maintain
• Remove or update obsolete tests when code changes
• Run tests frequently during development

Documentation & Communication

• Write tests that serve as documentation for expected behavior
• Include comments for complex test logic or non-obvious test scenarios
• Ensure test failures provide clear information about what went wrong