You can easily test your plug-in under different conditions by customizing the launching program and VM arguments on the Arguments Tab.
Program arguments are application-specific values that the application code expects and processes. For example, the -debug argument puts the platform in debug mode and enables tracing, while the -nl fr arguments launch the application in a French locale.
VM arguments are typically values that change the behaviour of the Java Virtual Machine (JVM). For example, the -Xmx256M argument allows the Java heap to grow to 256MB.
The Eclipse runtime is also configurable via many system properties which can be passed as VM arguments in the form: -DpropertyName=propertyValue. For example, -Dosgi.clean=true clears all data cached by the OSGi framework and the Eclipse runtime.
For a list of the program and VM arguments supported by the Eclipse runtime, refer to the following documents:
If you would like the same set of program and VM arguments to be used for all your launch configurations, it is recommended that you use the Launching Arguments setting when editing your Target Platform to create a template that gets propagated into all newly-created launch configurations.
The Working Directory specifies the directory in which the runtime Eclipse application executes (e.g. read and write files into the working directory, etc.). By default, the working directory is the root directory of the Eclipse installation; but, it can be configured by the user to be any writable directory they wish.
Eclipse Application Launcher
JUnit Plug-in Test Launcher
OSGi Framework Launcher
Junit Launcher Test Tab