My unit test local class templates
I try to write unit tests for as much of my code as I think makes sense. To speed up the creation of my unit tests, I’ve set up two ABAP templates in eclipse which I want to share with you in this post.
The local test helper class
I try to adhere to the recommendation of the SAP style guide for Clean ABAP of putting help methods in help classes. I typically create several local test classes for the same class under test to avoid making one huge local test class. These local test classes can then share the common help methods which I’ve put into the local test helper class. I typically make the help methods available to the local test classes through inheritance.
Some examples of when I create help methods are:
- I want to do asserts for several attributes of a complex object.
- I want to create a complex object. In the test methods, I then change the specific attribute which I’m interested in testing by using a set method.
My template for the local test helper class looks like this:
CLASS lth_unit_tests DEFINITION ABSTRACT. PROTECTED SECTION. METHODS assert_complex_entity IMPORTING act TYPE REF TO zcl_complex_entity exp TYPE REF TO zcl_complex_entity. METHODS create_mock_complex_entity RETURNING VALUE(result) TYPE REF TO zcl_complex_entity. ENDCLASS. CLASS lth_unit_tests IMPLEMENTATION. METHOD assert_complex_entity. cl_abap_unit_assert=>assert_equals( act = act->get_description( ) exp = exp->get_description( ) ). cl_abap_unit_assert=>assert_equals( act = act->get_start_date( ) exp = exp->get_start_date( ) ). ENDMETHOD. METHOD create_mock_complex_entity. result = zcl_complex_factory=>create_complex_entity( description = `My test description` start_date = '20200330' ). ENDMETHOD. ENDCLASS.
The local test class
In the local test classes, I put the actual tests. To be able to access the helper methods of the local test helper class, I let the local test classes inherit
Depending on if I use the factory pattern, the
setup method might call a factory to instantiate
cut instead of directly using the
NEW keyword. I rarely use
teardown so I often end up deleting these three methods from the local test classes.
CLASS ltc_unit_tests DEFINITION INHERITING FROM lth_unit_tests FINAL FOR TESTING DURATION SHORT RISK LEVEL HARMLESS. PRIVATE SECTION. DATA cut TYPE REF TO zif_my_interface. CLASS-METHODS: class_setup, class_teardown. METHODS: setup, teardown, first_test FOR TESTING. ENDCLASS. CLASS ltc_unit_tests IMPLEMENTATION. METHOD class_setup. ENDMETHOD. METHOD setup. cut = NEW zcl_my_class( ). ENDMETHOD. METHOD teardown. ENDMETHOD. METHOD class_teardown. ENDMETHOD. METHOD first_test. " given " when " then cl_abap_unit_assert=>fail( msg = 'Implement the first test here' ). ENDMETHOD. ENDCLASS.
I’m curious to hear what feedback you have on the templates above, and if you have suggestions for improvement.
This blog post first appeared on the Developer Voyage blog at https://www.developervoyage.com/2020/04/01/my-unit-test-local-class-templates.html
Why do you need a TEARDOWN method of any description? What sort of things do you put in that method?
I was a bit worried to see a ROLLBACK WORK in the above example because test classes never update the database. They always use test doubles for database acces...
That's a good point. I haven't really used the TEARDOWN method. I'll update the post.
I think that any Unit test framework may be used not only for unit tests. Also for integration tests when you can test Data Access Layer for example. For this task you need predefined data in database tables. You insert these records with SETUP method and delete them with TEARDOWN method.
A small side note regarding the usages of CLASS_SETUP, CLASS_TEARDOWN, and TEARDOWN fixtures w.r.t ABAP SQL Test Double Framework.
If one is using this TDF, then they would need the CLASS_SETUP, CLASS_TEARDOWN to create and destroy the mock SQL environment respectively.
I’ve seen developers clearing the mock data in the TEARDOWN fixture, although i personally prefer to do that in the SETUP.
Thanks for the input! I'm on an older NetWeaver release, which doesn't provide the ABAP SQL Test Double Framework.