Testing Strategy

When to Use

Instructions

1. Identify the type of code being tested:
   • Pure logic (calculations, transformations) → Unit tests
   • Integration points (database, API, file I/O) → Integration tests
   • User workflows (end-to-end paths) → E2E tests
2. Apply the testing pyramid:
   • Many unit tests (fast, isolated, cheap)
   • Fewer integration tests (slower, test boundaries)
   • Minimal E2E tests (slowest, test critical paths only)
3. Test naming convention:

   test_<function>_<scenario>_<expected_result>

4. Each test should have: Arrange, Act, Assert (AAA pattern)
5. Prioritize testing:
   • Error paths and edge cases over happy paths
   • Public API over internal implementation
   • Complex logic over trivial getters/setters
6. Coverage goal: aim for 80% on business logic, don't chase 100% everywhere

Examples

calculate_discount()

• Unit test:

  test_calculate_discount_percentage_applied_correctly

• Unit test:

  test_calculate_discount_zero_amount_returns_zero

• Unit test:

  test_calculate_discount_negative_amount_returns_error

• Unit test:

  test_calculate_discount_exceeds_max_caps_at_limit