Convert %Plug.Conn{} Struct to JSON

protocol.ex

defmodule Encoders do
  alias Jason.Encoder
  alias Encoder.BitString

  defimpl Encoder, for: Tuple do
    def encode(data, options) when is_tuple(data) do
      data
      |> Tuple.to_list()
      |> Encoder.List.encode(options)
    end
  end

  defimpl Encoder, for: PID do
    def encode(pid, options) do
      pid
      |> inspect
      |> BitString.encode(options)
    end
  end

  defimpl Encoder, for: Function do
    def encode(_, _) do
      "Function"
    end
  end
end

# Then inside the module where you need to `conn |> Jason.encode`
require Protocol
Protocol.derive(Jason.Encoder, Plug.Conn)
Protocol.derive(Jason.Encoder, Plug.Conn.Unfetched)