Test Harness

What is a Test Harness?

A test harness is a collection of software and test data configured to test a program by running it under varying conditions and monitoring its behaviour and outputs.

Key Components of a Test Harness

• Test Execution Engine: Runs the test cases automatically.
• Stubs and Drivers: Simulate missing components that the code under test depends on.
• Test Data Sets: Predefined input data used to exercise the code.
• Result Comparison Logic: Compares actual outputs against expected outputs automatically.

Why Test Harnesses Matter

Test harnesses are especially important in automated and unit testing, enabling code to be tested in isolation before all its real dependencies are available, and allowing tests to be run repeatedly and consistently.