Elixir snippets for writing libraries

config_validate.ex

defmodule ConfigValidate do
  def ensure_value_is_not_nil(key, value, suggestion) do
    if value == nil do
      raise """
      Please set #{key} under mix.exs project configuration.

      def project do
        [
          ...
          #{suggestion}
          ...
        ]
      end

      """
    end
  end
end

git_info.ex

defmodule GitInfo do
  @spec author_email() :: binary()
  def author_email() do
    case System.cmd("git", ["config", "--get", "user.email"]) do
      {email, 0} -> email |> String.trim()
      _ -> "author@example.com"
    end
  end
end