The execution of test cases is initiated as a client to the Integration Server hosting the services to be tested. For this reason, the inputs supplied to the service during execution and the expected outputs need to be serialized over the client-server interaction. If the input or output pipeline contains non-serializable objects, these objects are either lost or seen incorrectly during test execution. In addition, the service input needs to be more dynamic in nature than the static pipeline setup in the test case. Pipeline Filter helps to resolve these issues.

The Pipeline Filter is set once for the entire suite and provides a callback mechanism for the test developer to inject code that can modify various pipeline objects during execution. The Pipeline Filter is a class that implements the com.wm.ps.test.PipelineFilter interface and enables a user to add, remove, or change variables in the pipeline that are created from files, as pipelines created from files may not be able to persist custom java objects. The output pipeline from a service can also be filtered using the appropriate method. Only one such instance of the implementing class is created for the test suite and the name of test case is passed as a parameter.

The pipeline filter can be setup for the test suite in the main panel for the suite parameters.