How to test a dialog/how to pass data to action for testing?

Hi,

My action needs some external data, which the user will providevia a dialog: Action -> Open Dialog -> Compute

Apparently writing a test for this is not possible after some google search. (also checking the code, the "headless dialog" has getWindow() == null which throws when i do dialog.show();

The question is now, how do i test something like this? I cannot pass in any data to an action since it is getting executed by passing in a string:

myFixture.performEditorAction(ACTION_ID)

Sure i could pass the data via static variables, but this is ugly. Is there no better way?