Simple Event Bus based on Wisper

event_bus.rb

class EventBus
  def initialize
    @publisher = Class.new do
      include Wisper::Publisher
      public :broadcast
    end.new
  end

  def subscribe(listener, options = {})
    @publisher.subscribe(listener, options)
    self
  end

  def broadcast(event_name, payload)
    @publisher.broadcast(event_name, payload)
    self
  end
end

event_bus = EventBus.new

listener = double
payload = {}
event_name = 'my_engine.thing_created'

expect(listener).to receive(event_name).with(payload)

event_bus.subscribe(listener)

event_bus.broadcast(event_name, payload)

# Provided events are namspaced to avoid collisions this might be preferable to subscribing globally to concrete classes.