2.12 Testing

Components should be tested individually before final integration to identify issues early and reduce complexity.

Components include:

• Software
• Hardware
• Data
• Interfaces
• Resulting service (final product)

Testing components individually simplifies fault diagnosis.

• Concept: Validates ideas early (low cost, limited detail)
• Unit: Tests individual functions (fast, isolated)
• Boundary: Tests edge values (finds limit errors)
• Integration: Tests combined components (complex setup)
• Performance: Measures speed/resource usage
• System: Tests the full solution end‑to‑end
• Acceptance: Confirms requirements met
• Usability: Tests user interaction
• Regression: Ensures changes don’t break features
• Load/Stress: Tests under heavy demand
• Closed box: No code knowledge
• Open box: Code‑aware testing

Unit test example:

def add(a, b):
    return a + b

assert add(2, 3) == 5
        

Boundary test example:

def validate_age(age):
    return 0 <= age <= 120

assert validate_age(0)
assert not validate_age(121)
        

Automation reduces manual effort and increases consistency.

Methods include:

• Macros – automate repetitive actions
• Scripts – automated test execution
• Functional testing tools

Python script example:

for i in range(5):
    print("Running test", i + 1)
        

Test data is used to verify correctness.

• Valid: Expected to pass
• Invalid: Expected to fail
• Boundary: Edge values
• Erroneous: Incorrect type/format

Python example:

test_values = [50, -1, 100, "abc"]

for value in test_values:
    print(value)
        

A test plan defines how testing will be carried out.

It includes:

• Tests to be carried out
• Purpose of each test
• Test data used
• Expected results
• Actual results

Test plans ensure consistent and repeatable testing.