Howto test classes laying in a project with template = app?

[70thCommander]

Hello Community,

I want to test a class in a test project which is laying in a project with ".pro" file

TEMPLATE = app

How can I test those classes?

[wysota]

Write a test program and add the file to your test project.

[70thCommander]

How can I reference those project if the result is an exe file?
(Sorry, want to reply on your answer!)

[wysota]

You reference files, not projects.
SOURCES += relative/path/to/directory/name-of-file.cpp