Unit Testing

Unit tests exercises individual units of code to determine whether such code is correct and fit for use.

Best Practices

Test cases should be effectively laid out with the following structure:

• Setup
• Execution
• Validation
• Cleanup

Additional best practices:

• Tests should abstract common setup and teardown logic
• Tests should allow a margin for time-related tests
• Test code should be treated with the same love, care and respect as your production code! Test code must work for both positive and negative cases, last a long time, be readable and maintainable, and use sound patterns and conventions.

Anti-Patterns

Test code has anti-patterns, just like product code. Some of the biggest offenders are:

• Tests should not depend on system state that were manipulated by previous tests
• Tests should not depend on other tests
• Tests should not test precise timing or performance
• Tests should not have all-knowing oracles
• Tests should not test implementation details
• Tests should not be slow