Running ExUnit tests from iex shell

Hello everyone,

I’m trying to run ExUnit tests from the shell, and I almost got it working:

iex(2)> ExUnit.start(autorun: false)                                                                            
iex(3)> test_file = "test/sample_test.exs"
iex(4)> Mix.Compilers.Test.require_and_run([test_file], ["test"], formatters: [ExUnit.CLIFormatter])


Finished in 3.6 seconds
8 tests, 0 failures
{:ok, %{excluded: 0, failures: 0, skipped: 0, total: 8}}

So far so good, but the second run of Mix.Compilers.Test.require_and_run/3 doesn’t seem to do anything:

iex(5)> Mix.Compilers.Test.require_and_run([test_file], ["test"], formatters: [ExUnit.CLIFormatter])

Finished in 0.00 seconds
0 failures

{:ok, %{excluded: 0, failures: 0, skipped: 0, total: 0}}

It looks like the test compiler caches the test results. If that’s the case, can it be forced to invalidate it and run the tests from scratch again?

Wild guess here, but I think require_and_run might check if all the files are required, and then chain it with a literal && - so if the files are already required, it might return false and the second part would not be executed.

Like I said, idk, but it makes sense to me.

EDIT: Maybe the second time just run .run? Another wild guess.

EDIT2: and just because I am curious, why do you need this?

Did you mean ? Unfortunately, it didn’t help.
There are currently 2 reasons as to why I want to do this:

  1. to be able to pass the results of the tests, for instance, show the tests running on a web page;
  2. to be able to debug the unit tests with tracing tools, like Rexbug/redbug etc.

Unfortunately I don’ t really know what you are talking about - but it sounds like a CI Server.

I like to actually be in charge of when to deploy updates or upgrades (which is something a UI server should consider.)

Kind of weird that nobody has implemented anything yet, but I guess you are on your own for now.

Interesting idea! Mix tasks don’t re-execute by default. Try running Mix.Task.clear/0 before require_and_run (docs:

Unfortunately, no luck with Mix.Task.clear/0.

I wanted to do this because of the apps I’m working in at the moment has a long startup time, making TDD painful. Someone pointed me to a solution based on TestIex — Easier Test Driven Development in Elixir | by Daniel Olshansky | Medium and it works like treat.


basically you have to load it again to rerun the test


or even better compile_file, since load_file is depricated


then you can rerun

Mix.Compilers.Test.require_and_run([test_file], ["test"], formatters: [ExUnit.CLIFormatter])
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