how to successfully mock Celluloid with rspec

Question

Well, I'm exhausted. Exhausted in a sense run out of options.

We have Supervisor that manage an actor(s).

supervisor = Celluloid::SupervisionGroup.run!

airbrake = supervisor.pool(Flango::AirbrakeActor, as: :airbrake_actor, size: 1)

All I need to do is mock the airbrake actor which has a method notify_exception .. defined in it.

i.e the following call

airbrake.async.notify_exception('exception') 

The relevant rspec code ...

expect(airbrake.async).to receive(:notify_exception).with('exception')

I have tried this.. Does not work

Tried the following approach (not sure what I'm doing)

airbrake = OpenStruct.new(:async, Flango::AirbrakeActor.new)

This work but the test hangs at the end and until killed.

Any help?

Answer 1

I was able to make it work after 2 changes.

One issue was that you were closing celluloid and then using dead variables. So i refactored startup code in init

require 'bundler'
Bundler.setup(:default)
require 'ffi-rzmq'
require 'celluloid/zmq'
require 'celluloid/current'
require 'securerandom'
Celluloid::ZMQ.init
class SockOne
  include Celluloid::ZMQ
  attr_reader :sock
  def initialize
    @sock = PullSocket.new
    @sock.connect('tcp://127.0.0.1:20483')
  end

  def read
    loop do
      middleware.async.start(sock.read_multipart)
    end
  end
end

class SockTwo
  include Celluloid::ZMQ
  attr_reader :sock
  def initialize
    @sock = PushSocket.new
    @sock.connect('tcp://127.0.0.1:20484')
  end

  def send_response(other_id, id, response)
    start_time = Time.now
    sock.send(response)
  end
end

class Middleware
  include Celluloid
  def start(data)
    puts "i am starting middleware with " + data
    Handler.new.start(data)
  end
end

class Handler
  def start(data)
    begin
      execute(data)
    rescue => exception
      airbrake.async.notify('some exception')
    ensure
      sock_two.async.send_response(['i got a reply'])
    end
  end

  def execute(data)
    data
  end
end

class Airbrake
  include Celluloid
  def notify(data)
    puts "this is notify to airbrake - " + data
  end
end

def init
  supervisor = Celluloid::SupervisionGroup.run!
  $middleware = supervisor.pool(Middleware, as: :middleware, size: 10)
  $sock_two = supervisor.pool(SockTwo, as: :sock_two, size: 10)
  $airbrake = supervisor.pool(Airbrake, as: :airbrake, size: 1)
end

def airbrake
  $airbrake
end

def sock_two
  $sock_two
end

def middleware
  $middleware
end

if $0 == __FILE__
  puts "Starting.."
  sock_one = SockOne.new
  sock_one.read
end

And then refactored the main_spec.rb like below

require 'rspec'

require_relative 'main'

describe 'Handler' do
  describe '#start' do
    before(:each) do
      Celluloid.shutdown
      #init()
      Celluloid.boot
      init()
    end

    it 'should invoke async call to celluloid' do
      handler = Handler.new
      expect(handler).to receive(:execute).with(['1', '2', '3']).and_raise('boom')

      # This does not work
       airbrake.wrapped_object.instance_eval do
         def notify(data)
            puts "new data was called - " + data
         end
       end

      expect(airbrake.wrapped_object).to receive(:notify).with('some exception')

      handler.start(['1', '2', '3'])
    end

    after(:each) do
      Celluloid.shutdown
    end
  end
end

And now it works