Functionaly pure message passing

[mjadczak]

@voughtdq

(Not true in every case, e.g. GenServer.reply/2)

Couldn’t you use an arbitrary {to, tag} ?

i.e.

def test_gen_server_call(msg) do
  ref = make_ref()
  Server.handle_call(msg, {self(), ref}, nil)
  receive do
    {^ref, reply} -> assert_this_reply_is_correct(reply)
  end
end

It may be the case that the reply never comes if, e.g. the GenServer is (logically) waiting for some other call or cast before it decides to reply to the original caller.