In bottom-up testing, lowest-level modules or system components are integrated and tested first, after which we move hierarchically upwards. A driver test program that invokes the test module is required. The testing starts with drivers calling the lowest-level modules. We then integrate the tested components one at a time carefully looking into any interface issues, moving upward until the complete system is tested.
Advantages of Bottom-Up testing
- Bottom-Up testing is appropriate for object oriented systems, for testing distributed models and simulations etc.
- Test conditions are easier to create.
- Bottom-up testing does not find a major problems until late in the process.
Also See:
Top-Down Testing
Testing Stubs & Drivers
Integration Testing