Rails - unit tests for require file

Is there any way for unit testing whether correct file is getting required/loaded.

say for eg.

I am in file a2, and I need to require the file a1, but by mistake I added,

require some_file_path/a2 

inside the same file a2, tests succeeded, I didn't get any err in development evn, but it blew up in production, is there any way for catching this in unit tests.