Support config option to start without ExUnit hooks.

[jimsynz]

Hi there.

I'm using Bypass with espec. It'd be amazing if it were possible to just call Bypass.open without it exploding - I'm currently starting and stopping the bypass supervisor in my test setup and teardown.

[MSch]

Hi James,

Bypass needs ExUnit's on_exit callbacks to check if a request actually arrived at the started Plug (and to rethrow an exception that happened). If you can come up with a solution that makes Bypass work with ExUnit as well was espec I'd be happy to merge it. I'm assuming adding an application configuration to tell bypass whether it's running in ExUnit or espec would make sense, what do you think?

[jimsynz]

Okay. I'll have a think about how we could have it work. I'd suggest that we abstract it into separate "drivers" for each test framework.

[MSch]

Hi @jamesotron, just wanted to check if you found a workaround in the meantime?

[mwean]

@MSch this is what I did that seems to work against master:

  before_all do
    Application.ensure_all_started(:bypass)
  end

  let :bypass, do: start_bypass

  finally do
    case Bypass.Instance.call(bypass.pid, :on_exit) do
      :ok ->
        :ok
      :ok_call ->
        :ok
      {:error, :not_called} ->
        raise ESpec.AssertionError, "No HTTP request arrived at Bypass"
      {:error, :unexpected_request} ->
        raise ESpec.AssertionError, "Bypass got an HTTP request but wasn't expecting one"
      {:exit, {class, reason, stacktrace}} ->
        :erlang.raise(class, reason, stacktrace)
    end
  end

  def start_bypass do
    case Supervisor.start_child(Bypass.Supervisor, []) do
      {:ok, pid} ->
        port = Bypass.Instance.call(pid, :port)
        %Bypass{pid: pid, port: port}
      other ->
        other
    end
  end

[MSch]

This looks excellent. We are not using espec ourselves, but if you submit a PR on top of #36 we can merge this in. 👍

[MSch]

FYI I just released 0.8.0 of bypass with @tompave's ESpec support included ❤️