ABAP_to_the_Future

Writing and Implementing Unit Tests 3.3
3.7, you add not only the normal definition line but also a line about FRIENDS; this
is the line that enables you to test private methods of your main class. In the following
example, the global class you will be testing is the monster simulator, and
the only way you can test its private method s is if you make it friends with the
test class.
*"* use this source file for your ABAP unit test classes
CLASS lcl_test_class DEFINITION DEFERRED.
CLASS ycl_monster_simulator DEFINITION LOCAL FRIENDS lcl_test_class.
Listing 3.7 Defining a Test Class
A lot of people say that testing private classes is evil and that you should only test
the methods the outside world can see. However, over the course of time so
many bugs have been found in any method at all, be it public or private, that you
should have the option to test anything you feel like.
General Settings for a Test Class Definition
Once you have created the class, it’s time to establish the general settings for the
class, as shown in Listing 3.8.
CLASS lcl_test_class DEFINITION FOR TESTING
RISK LEVEL HARMLESS
DURATION SHORT
FINAL.
Listing 3.8 Test Class General Settings
Take this one line at a time. In the first line, tell the system this is a test class and
thus should be invoked whenever you are in your program and take the Unit
Test option from whichever tool you are in (the menu path is subtly different
depending on which transaction you are in).
Now, you come to RISK LEVEL . For each system, you can assign the maximum
permitted risk level. Although unit tests never run in production, it is possible for
them to run in QA or development. By defining a risk level, you could, for example,
make it so that tests with a DANGEROUS risk level can’t run in QA but can run
in development. (Leaving aside that I feel unit tests should only be run in development,
how could a unit test be dangerous? I can only presume it’s dangerous if
it really does alter the state of the databaseor fire a nuclear missile. Try as I might,
I can’t think why I would want a test th at was dangerous. Tests are supposed to
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