My solution to this to get the token in test_helper.exs put it in the env and then in test’s setup pick the token from the env for the tests that need it.

Application.put_env(
  :app,
  :token_key,
  get_token()
)
// test
  setup_all do
    token = Application.get_env(:app, :token_key)

@adw632’s solution would work if all your tests that need the token are in the same testfile. setup_all would run just once before all these tests, but as far as I know there is currently no way to set a “before” hook to run once before all the tests, there is one for after all tests after_suite/1.

Yes ExUnit is designed to isolate tests and test suites so you don’t get leakage and side effects between tests.

It even randomizes the order to help catch unintended dependencies and side effects to make testing robust.

You could use the test_helper compile time “evil” that @Hermanverschooten showed to create a globally fixed value.

You could also use many of the nicely explained flakey test approaches to undo all the goodness that ExUnit provides and make your tests flakey and evil too.

Such evil can include stashing a Req structure in the Application environment or Ets. So in your setup_all callback you try and get the Req struct and only create and set it if it is doesn’t yet exist.

You will likely introduce a race condition on the create which you thoughly deserve for doing such evil things.

I would just use setup_all to do the authentication once per test suite. How many test suites do you have?

Perhaps you need to think about Mocking?