Testing related groups of functions.
testing of individual hardware or software units or groups of related units [ IEEE 90].
Testing of individual software components. ()
In computer programming, a unit test is a procedure used to validate that a particular module of source code is working properly. The procedure is to write test cases for each function and method so that whenever a change is made to unit-tested code, its unit test will fail. The malfunctioning code can then be quickly identified and fixed. Ideally, each test case is separate from the others. This type of testing is mostly done by the developers and not by end-users. See Test Driven Development (TDD).
Unit testing is the process of performing tests on small components of a product in their isolation, prior to these components being integrated into the complete product for system testing.
In computer programming, unit testing is a procedure used to validate that individual modules or units of source code are working properly.