Unit testing UI rules Unit testing a harness The Run Rule feature enables you to test a harness individually before testing it in the context of the application you are developing. You specify a test page for the rule to use, provide sample data as the input, run the rule, and examine the results. Unit testing a section The Run Rule feature enables you to test a section individually before testing it in the context of the application you are developing. You specify a test page for the rule to use, provide sample data as the input, run the rule, and examine the results.