anonymous_plug_test.exs

  defmodule SomeApp do
    defmodule SomeController do
      use Plug.Builder
      plug Plug.Session,
        store: :cookie,
        key: "_wankrank_key",
        signing_salt: "cmwAUEpB",
        max_age: 86400
      plug :fetch_session
      plug Anonymous
    end
  end

	@default_opts [
			store: :cookie,
			key: "_wankrank_key",
			signing_salt: "cmwAUEpB",
			max_age: 86400
		]

	@custom_serializer_opts Plug.Session.init(@default_opts)

  test "assigns user_id session key" do
    conn = conn(:get, "/") |> SomeApp.SomeController.call([])
		refute get_session(conn, :anonymous_id) == nil
  end

  test "returns existing user session key" do
    conn = conn(:get, "/") |> Plug.Session.call(@custom_serializer_opts) |> fetch_session
		conn = put_session(conn, :anonymous_id, "some_id")
		conn = conn |> SomeApp.SomeController.call([])
    # conn = put_session(conn, :anonymous_id, "some_id")
    # conn = conn |> SomeApp.SomeController.call([])
    assert get_session(conn, :anonymous_id) == "some_id"
  end