Is it possible to get the compiler to exit early, failing the build, if a compile time warning is raised?

Question

I find the compile time warnings very useful, but I can occasionally miss them, especially if it\'s on a pull request where the tests are running on a CI server.

Ide

Answer 1

I like Michael Stalker's solution here.

Treating warnings as errors always can get annoying during TDD, where you might be rapidly refactoring code while running tests.

Instead, you can make the --warnings-as-errors flag conditional on your Mix env like this:

defmodule SomeProject.MixProject do
  use Mix.Project

  def project do
    [
      elixirc_options: [
        warnings_as_errors: treat_warnings_as_errors?(Mix.env())
      ]
      # ...
    ]
  end

  defp treat_warnings_as_errors?(:test), do: false
  defp treat_warnings_as_errors?(_), do: true
end

Warnings will go ignored when testing, but not for a dev or prod compilation.