A test driver is a software component or script designed to invoke the unit or module being tested. It simulates the behavior of higher-level modules or programs that would normally call the unit under test. Test drivers are used primarily in bottom-up integration testing, where lower-level components are tested before higher-level components.
Key Characteristics of Test Drivers:
- Invocation: It directly calls and tests functions, classes, or modules that cannot be invoked in the normal testing flow.
- Input Handling: The driver supplies test inputs to the module and collects the outputs.
- Simulation of Higher-Level Code: Since lower-level units may not yet be integrated into the complete system, the test driver mimics the calls from higher-level components.