If you write additional features for the Eclipse platform in the form of plug-ins, you can use component tests to test the plug-ins in their environment.
Testing plug-ins is similar to testing standard Java components; the same basic principles and techniques apply. You can test plug-ins using method-level or scenario-based test patterns. The main difference is in the type of test project.
Just as plug-ins must be located in plug-in projects in order to be handled and deployed as plug-ins, component tests of plug-ins must be contained in plug-in test projects. These special test projects are created exactly the same way as standard test projects, except that the scope of a plug-in test project can only contain plug-in projects.
When you run a plug-in component test from a plug-in test project, a new instance of the development platform is launched, containing the plug-in under test and the test environment.