Up to and including Release 3.1, calling function modules with the function FUN in CATT was intended to use the functionality of the function module, not to test it.
The new test functionality tests any function modules with any interface. The function modules can contain dialogs.
You can choose 'Record function module' in the CATT transaction initial screen to create a CATT object to test a function module. Specify the function.
Specify the import, changing and table interface on the next screen. The function module then runs.
If the function module contains dialogs, the screens with your entries are recorded. You can parameterize these entries later as in a CATT transaction test.
At the end of the function module, the result is displayed and recorded.
The result of later function module tests is compared with the recorded result.