⚙️ Set your preferred CLI env for mix aliases
Notes
At some point, you might introduce a new mix alias to run a subset of your
tests.
It might be that you only want to run feature tests or live tests or that you want a special command to include tests that hit external resources (maybe something you only run once a day in CI).
Say, we have an alias to run our feature tests (which we tagged with live):
mix test.live
But when we try to run that command, we get an error!
** (Mix) "mix test" is running in the "dev" environment.
We could, of course, fix that by specifying MIX_ENV=test when we run the mix
command.
MIX_ENV=test mix test.live
But that’s so frustrating! 😩
Thankfully, there’s a better way!
We can simply specify the preferred CLI environment for our script with
preferred_cli_envs in your project definition. 🙌
defp preferred_cli_envs do
["test.live": "test"]
end
Update since Elixir 1.15
It seems that since Elixir 1.15 you don’t have to add a preferred_cli_envs key
in the project. You can simply specify it in a new cli/0 function like this:
def cli do
[
preferred_envs: ["test.live": :test]
]
end
For more, see Mix.Project’s CLI configuration