Integration Testing is a level of software testing where individual modules are combined and tested as a group. The purpose of Integration testing is to expose faults in the interaction between integrated modules.
- Big Bang
- Top-Down
- Bottom-Up
- Sandwich/Hybrid
Big Bang is an approach to Integration Testing where all or most of the modules are combined together and tested at one go. This approach is taken when the testing team receives the entire software in a bundle.
Top-Down is an approach to Integration Testing where top-level modules are tested first and lower-level modules are tested step by step after that. This approach is taken when a top-down development approach is followed. Test Stubs are needed to simulate lower-level modules which may not be available during the initial phases.
Bottom-Up is an approach to Integration Testing where bottom level modules are tested first and upper-level modules step by step after that. This approach is taken when the bottom-up development approach is followed. Test Drivers are needed to simulate higher-level modules which may not be available during the initial phases.
Sandwich/Hybrid is an approach to Integration Testing which is a combination of Top-Down and Bottom-Up Approaches.
