Today I found out how to run your tests in a
--watch fashion, with Elixir and Mix.
Looking through the documentation for Mix.Task.Test you’ll find the
--stale option and
From the documentation for
The --stale command line option attempts to run only the test files which reference modules that have changed since the last time you ran this task with --stale.
--listen-on-stdin runs tests, and then listens on stdin. It will re-run tests once a newline is received