Unit Testing: In this we do all the technical tests like testing the data flow, logic in transformation, data loads, query properties etc
Integration Testing: In this we perform the function test to check that query is giving output which is functionally correct.
Regression Testing: If we are making changes to existing flow and query, it this testing one would like to test that no existing functionality has changed because of newly added changes.
Performance Testing: sometimes we write ABAP code in transformations, under this cap you may like to test the data load performance. If data load is taking a long time, you may want to optimize the code and check the performance again.
Authorization Test: in this you would like to test all the roles have been set up properly and data level access is also working fine at query level.
Attached doc Helps us to Test for SAP Reports in Quality Environment.
Regards
NK