Integration Testing

Integration Testing

•Bottom - up testing (test harness).

•Top - down testing (stubs).

•Modified top - down testing - test levels independently.

•Big Bang.

•Sandwich testing.

Top-Down Integration Testing

•Main program used as a test driver and stubs are substitutes for components directly subordinate to it.

•Subordinate stubs are replaced one at a time with real components (following the depth-first or breadth-first approach).

•Tests are conducted as each component is integrated.

•On completion of each set of tests and other stub is replaced with a real component.

•Regression testing may be used to ensure that new errors not introduced. 

Bottom-Up Integration Testing

•Low level components are combined in clusters that perform a specific software function.

•A driver (control program) is written to coordinate test case input and output.

•The cluster is tested.

•Drivers are removed and clusters are combined moving upward in the program structure.