Document how to override the MIX_ENV when running hooks

[adamwight]

I have a typical use case, a pre_push hook will run tests before uploading patches to the remote repository. The default environment is dev so , but my tests should run in the test environment. I end up having to run this awkward command to get the correct environment:

MIX_ENV=test git push

Is there a recommended way to transparently override the environment? Should this be included in the documentation?

[adamwight]

Perhaps the git_hooks configuration could support a general environment override like,

environment:
  MIX_ENV: test

... or a specific one like,

mix_env: test

For me, a reasonable workaround is to manually edit .git/hooks/pre_push to include the line,

MIX_ENV=test mix git_hooks.run pre_push "$@"

but it would be better to set the environment within the git_hooks.run mix task, to make it dynamically configurable without having to reinstall the hook.

[qgadrian]

@adamwight can you post your git_hooks configuration?

If you use a string to run the mix task, you will need to declare the mix environment, as in your example. But instead of that, you can use {:mix_task, :test} and you won't need to do anything else.

The README states that are the preferred option but feel free to submit any PR if you believe it's not clear enough ☺️

[adamwight]

I see what you mean, now. "mix test" was a bad example because it correctly assumes it should be running in the test environment. However, I have other tasks which still need the environment set explicitly—maybe the problem is in how I've configured these tasks, not in how git_hooks runs them.

My configuration looks like this,

if Mix.env() == :test do
  config :git_hooks,
    verbose: true,
    hooks: [
      pre_push: [
        tasks: [
          {:mix_task, :clean},
          {:mix_task, :compile, ["--warnings-as-errors"]},
          {:mix_task, :format, ["--check-formatted"]},
          {:mix_task, :credo, ["--strict"]},
          {:mix_task, :test},
          {:mix_task, :coveralls},
          {:mix_task, :dialyzer},
          {:mix_task, :doctor}
        ]
      ]
    ],
    extra_success_returns: [
      # The compile step is being obstinate, it seems to give a special result
      # when run with --warnings-as-errors.
      {:ok, []}
    ]

and in my mix.exs, I have deps like:

{:credo, "~> 1.0", only: :test, runtime: false}

So the "mix credo" task is only accessible when MIX_ENV=test.

[adamwight]

This is the magic I was looking for... feel free to close the issue!

# mix.exs
def project do
  [
    # ...
    preferred_cli_env: [{:"git_hooks.run", :test}]
  ]
end

[qgadrian]

I checked how to change the mix environment at runtime some time ago but couldn't find a way.

You could use credo on dev environment as an alternative, but glad you worked it out!