TestTask: running no tests should fail

[grosser]

just managed to make a PR that moved all files ... so no tests ran ... but travis passed ... good times ... would you accept a PR to make it fail on empty file list ?

[hsbt]

just managed to make a PR that moved all files ... so no tests ran ... but travis passed ... good times ...

Please tell me this use-case detail? I interested this change.

[grosser]

Had a bug where the Dockerfile would not add the tests into the test folder, but the root ... so test task did not find them.

Other usecase I had just yesterday: rspec-rails did not get loaded in rake tasks -> default task still pointed to test folder ... so no tests ran, but the build was green for a week ... good times.

[fatkodima]

@grosser 👍 on this. Was in this trap too. Would you mind opening a PR?

[grosser]

I'd expect this to be a big change since this is about file handling primitives and would need some buy-in from maintainers since it will break compatibility 😞