ABAP_to_the_Future

3
ABAP Unit and Test-Driven Development
The first step is to break up the dependencies. In this section, you will learn how
to do exactly that, a process that involves two basic steps:
1. Looking at existing programs to identifysections of code that are dependencies
(and are thus candidates to be replaced by mock objects during a test)
2. Changing your production code to se parate out the concerns into smaller
classes that deal with each different type of dependency
3.1.1 Identifying Dependencies
Listing 3.1 is an example of a common AB AP application. In this case, our good
old friend the baron (remember him from Chapter 2?) does not want any neighboring
mad scientists building monsters and thus encroaching on his market, so
as soon as hears about such a competitor he drops a nuclear bomb on him (as any
good mad scientist would). Listing 3.1 illustrates this by first getting the customizing
settings for the missiles and making sure they are ready to fire, then confirming
with the operator that he really wants to fire the missile, then firing the
missile, and finally printing out a statem ent saying that the missile was fired. At
almost every point in the code, you will deal with something or somebody external
to the SAP system: the database, the operator (user), the missile firing system,
and the printer.
FORM fire_nuclear_missile.
* Read Database
CALL FUNCTION 'READ_CUSTOMISING'.
* Query Missile Sensor
CALL FUNCTION 'GET_NUCLEAR_MISSILE_STATUS'.
* Business Logic
IF something.
"We fire the missile here
ELSEIF something_else.
"We fire the missile there
ENDIF.
* Ask user if he wants to fire the missile
CALL FUNCTION 'POPUP_TO_CONFIRM'.
* Business Logic
CASE user_answer.
WHEN 'Y'.
"Off we go!
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