Units tests are the lowest level of testing, designed to test the methods of each class.

For any new code written in GeoServer, one should write the corresponding test. There are classes that lack unit tests, but we're serious about getting better at it, so please help us out.

For some information on good unit tests, see: http://msdn.microsoft.com/msdnmag/issues/06/01/UnitTesting/default.aspx and http://blogs.zdnet.com/Burnette/?p=179

JUnit

JUnit is the java library we use to run our unit tests. Each module has a test directory that mirrors the structure of the src directory, put tests for each class in the corresponding package. You can run all units tests by executing the test maven task from the root of a module

[geoserver]% mvn test

We recommend running unit tests as frequently as possible, and before any commit.

For more information on writing junit tests explore junit.sourceforge.net.