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Published on 8/9/2025
Code Testing Best Practices

Rules

name: Code Testing Best Practices

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