Q. Briefly explain Integration Testing?

Integration Testing: In this the module are methodically integrated and tested to find protocol design error, interface problems, errors due to global values, input/ output format errors etc. Diverse strategies can be:

• Bottom up Integration: In this kind of testing the modules at the leaf level are first tested and then we move up in the hierarchy. Drivers are utilized in this type of testing at different levels of hierarchy. Driver is a program which accept the test case data to be inputted and printed by the module to be tested.
• Top Down Integration: In this case we start the top mainly module in the hierarchy and move down till the leaf modules are tested. Where ever necessary necessary stubs/ drivers are used. A stub is a program which simulate the module called by the module to be tested.
• Big-Bang Testing: In this all the modules subsequent to unit testing are combined and tested in one go. The problem with this forms of testing is debugging of errors.
• Sandwich Testing: This technique makes utilization of combination of top down and Bottom up testing.