Abort ExUnit on the first test that does not pass

Question

In Ruby, specifically RSpec, you can tell the test runner to abort on the first test that does not pass by the command-line flag --fail-fast. This helps a lot to not waste time or lose focus when fixing a lot of test in a row, for example when doing test-driven or behavior-driven development.

Now on Elixir with ExUnit I am looking for a way to do exactly that. Is there a way to do this?

Answer 1

There is such an option since Elixir 1.8.

Use the --max-failures switch to limit the number of tests evaluated with failure. To halt the test suite after the first failure, run this:

mix test --max-failures 1

Answer 2

Unfortunately there is (to my knowledge) no such flag implemented.

However, you can run a single test by

mix test path/to/testfile.exs:12

where 12 is the line number of the test.

Hope that helps!