[daleharvey]

Its not supposed to be impressive, its supposed to be quick enough to provide a reasonable feedback cycle, with the ability to run specific tests that is drastically reduced, you make a few changes, run the relevant tests (they can run automatically via watching), tests pass you are happy, if its an intrusive change you might want to run the full suite before pushing, then when you push CI runs a far more exhaustive set of tests (possibly across patforms), these can happily take a lot more time.

It differs very much across projects, full pouchdb test suite takes ~4 minutes, full firefox test suite takes hours, for rails ~4 minutes sounds entirely reasonable (kinda faster than I would expect) and wouldnt give me no reason to think about reducing the coverage and reliability of the tests by decoupling anything.