Tests stop working under xcode 8 TEST_HOST error

Question

I want to start tests under Xcode 8 and it fail in the beginning. My error is:

Could not determine bundle identifier for MyProjectTest\'s TEST_HOST:

Answer 1

I ran into this error a lot and eventually discovered that it was caused by varying PRODUCT_NAME between Debug and Release build configurations.

We were doing this so that the Debug builds had a different app name when installed on the phone (as well as a different bundle id so we could install them side-by-side with the App Store builds).

We reverted that change and added a new APP_DISPLAY_NAME setting to the build configuration, varied that between build types, and changed the Info.plist to use $(APP_DISPLAY_NAME) instead of $(PRODUCT_NAME).

After doing that, it's important to go into the test target in the project and make sure the 'Host application' setting in General is actually set to your application.