What is Test Driver?
Test Drivers are used during Bottom-up integration testing in order to simulate the behaviour of the upper level modules that are not yet integrated. Test Drivers are the modules that act as temporary replacement for a calling module and give the same output as that of the actual product.
Drivers are also used when the software needs to interact with an external system and are usually complex than stubs.
Driver - Flow Diagram:
The above diagrams clearly states that Modules 4, 5, 6 and 7 are unavailable for integration, whereas, above modules are still under development that cannot be integrated at this point of time. Hence, drivers are used to test the modules. The order of Integration will be:
4,2 5,2 6,3 7,3 2,1 3,1
Testing Approach :
+ Firstly, the integration between the modules 4,5,6 and 7 + Test the integration between the module 4 and 5 with Driver 2 + Test the integration between the module 6 and 7 with Driver 3