Middleware

Different from grape, middleware of maru is a standalone plug.
There's no before or after callback within middleware, middleware is just a plug with Maru.Response helper.

Ruby

defmodule Before do
  use Maru.Middleware

  def call(conn, _opts) do
    IO.puts "before request"
    conn
  end
end

defmodule API do
  use Maru.Router

  plug Before
  mount Router
end