Mutation testing for Elixir!

To get started with mutation testing, first add muzak as a dependency in your mix.exs file and set the preferred_cli_env for muzak to test:

defmodule MyApp.Mixfile do
  def project do
    [
      # ...
      preferred_cli_env: [muzak: :test]
    ]
  end

  # ...

  defp deps do
    [
      # ...
      {:muzak, "~> 1.1", only: :test}
    ]
  end
end

You're now ready to get started!

$ mix deps.get
$ mix muzak

Muzak will then randomly generate up to 1000 mutations in your application and run your test suite against each of them. If your application contains more than 1000 possible mutations, then you may see different results for subsequent runs.