How do I sbt test continually until a flakey test fails?

Question

If there is a test that fails only sometimes, can I ask sbt to run tests continually until failure?

Otherwise, I'm stuck hitting up-arrow while watching Arrow. (pun unintended but leavening)

https://stackoverflow.com/q/22366719/1296806

Answer 1

Old question, but having just had the same need myself, here is a solution: sbt will return non-zero exit code if you run it one off with the tests, so, one way to loop until it fails is to just look at the exit code in the shell:

while [ $? -eq 0 ]; do sbt test; done

Answer 2

I had the same problem, and I've ended up implementing this as a command.

lazy val root = Project("test", file(".")).
  settings(commands += Command.command("testUntilFailed") { state =>
    "test" :: "testUntilFailed" :: state
  })

The advantage is that it will skip the SBT loading. You can also add extra parameter or run testOnly to test a single test.