I'm going to let Travis run on this one.

@chrisseaton @nirvdrum @eregon I thought it would make sense for jt test to run all tests and then jt test would become jt test specs.

You've got it so that it's

jt test specs spec/ruby/language/while_spec.rb

But I think we can look at the path you supply to work out if it's MRI or RubySpec. We can tell the difference between

jt test spec/ruby/language/while_spec.rb

and

jt test test/test/mri/ruby/test_whileuntil.rb

automatically. Then jt test should probably run everything, jt test specs just specs, and jt test specs fast only the fast specs.

@chrisseaton updated jt per your comment