karma not processing coffeescript tests

[DisruptiveMind]

When opting for CoffeeScript, gulp test will run only JS files in the tmp and app folders.

I had to add modify in gulpfile.js

.queue(gulp.src(['./src/app/**/*_test.js', './.tmp/src/app/**/*_test.js']))

.queue(gulp.src(['./src/app/**/*_test.coffee']))

I remove the tmp folder checks to run the tests only on the coffee files.

I had to also modify karma.conf.js and add the plugin in manually following these steps: karma-coffee-preprocessor

The tests do run the coffeescript files now, is there a step I am missing?

Edit:
This only works after generating the files into the tmp folders otherwise the tests won't load all modules.