Unit Testing

A unit test, as Agile teams understand the term, is a short program fragment written and maintained by the developers on the product team, which exercises some narrow part of the product’s source code and checks the results. The outcome of a unit test is binary: either “pass” if the program’s behavior is consistent with the recorded expectations, or “fail” otherwise. Developers will typically write a large number of unit tests (corresponding to a large number of program behaviors of interest), called a “test suite”. By common convention dating back at least to the JUnit family of tools, the color red (as in “getting a red bar”) represents the failure of one or more tests. The color green (“a green bar”) denotes successful execution of “all” unit tests associated with a program.