Support `.only` concept for all files

[kentcdodds]

Right now, if you have multiple files with multiple tests, and you place .only on a test in one of the files, you might expect that it only runs that test (this is how jasmine and mocha operate), but what actually happens is all the tests in the other files will run. All that .only does right now is prevent tests in that same file from running.

I think it could be really handy (especially during development) to only run a few tests for the specific feature you're working on.

Right now, it's not entirely unreasonable to work around this by pointing AVA directly at the file that you're working in.

As for what it should be called, honestly I think that it should be .only and the current .only functionality should be renamed to something like .onlyInFile or something... I actually don't see a solid use case for the current functionality so perhaps this feature request could simply be renamed to something like: Change .only to be scoped to the entire test suite

Thoughts? 💭

[BarryThePenguin]

I'm in the same boat as Kent.

I wrote a bit about my use case in #471

I'm not aware of a reason for the current behavior or a .onlyInFile method.

[sindresorhus]

Agreed. This is a bug.

[naptowncode]

Looks like this could be done by sending the hasExclusive flag along with testCount in the ava-stats message. Then if api.run() gets any messages with hasExclusive: true it could send a runOnlyExclusive: true flag to the ava-run message. Does that sound right?

[novemberborn]

This landed in #556.