Testing ruby-amqp and evented-spec with MiniTest

example_amqp_spec.rb

require 'evented-spec'
require 'minitest/autorun'
require "amqp"

class TestConsumer
  attr_reader :connection_string, :queue_name, 
              :connection, :channel, :queue, 
              :msg_count, :errors

  def initialize opts={}
    @connection_string = opts[:connection_string] || 'amqp://localhost'
    @queue_name = opts[:queue_name] || ''
    @queue_opts = opts[:queue_opts] || {}
    @msg_count = 0
    @errors = 0
  end

  def start
    AMQP.connect @connection_string do |conn, connect_ok|
      @connection = conn
      AMQP::Channel.new @connection do |channel, channel_ok|
        @channel = channel
        @channel.queue @queue_name, @queue_opts do |queue|
          @queue = queue
          @queue_name = queue.name
          @queue.subscribe do |meta, payload|
            begin
              self.on_message meta, payload
              metadata.ack
            rescue Exception => err
              self.on_error meta, payload, err
              # TODO automatic retry/ backout logic
            end
          end
        end
      end      
    end
  end


  def on_message meta, payload
    raise ArgumentError, "Boom!" if payload == "Exception!"
    unless payload.nil?
      @msg_count += 1
    end
  end

  def on_error meta, payload, err
    @errors += 1
    meta.ack # don't leave msg on the queue
  end
end


describe TestConsumer do
  include EventedSpec::AMQPSpec

  default_timeout 5

  amqp_before do
    @q_name = "test.spec"
    @channel = AMQP::Channel.new
    @exchange = @channel.default_exchange
  end

  amqp_before :each do
    @consumer = TestConsumer.new :queue_name => @q_name
    @consumer.start
  end

  amqp_after :each do
#    @consumer.connection.disconnect
  end

#  context "when executing default behavior" do
    it "will have the correct initial state" do
      @consumer.connection_string.must_equal "amqp://localhost"
      @consumer.queue_name.must_equal @q_name
      @consumer.msg_count.must_equal 0
      @consumer.errors.must_equal 0
      done(0.1)
    end

    it "must start up correctly" do
      done(0.3) {
        @consumer.connection.wont_be_nil
        @consumer.channel.wont_be_nil
        @consumer.queue.wont_be_nil
        @consumer.connection.connected?.must_equal true
      }
    end

    it "should increment the counter" do
      @channel.queue @q_name do |q|
        q.purge # purge old messages first.
        @exchange.publish "hi", :routing_key => @q_name
      end

      done(0.3) {
        @consumer.msg_count.must_equal 1
        @consumer.errors.must_equal 0
      }    
    end

    it "should catch an exception" do
      @channel.queue @q_name do |q|
        q.purge # purge old messages first.
        @exchange.publish "Exception!", :routing_key => @q_name
      end

      done(0.3) {
        @consumer.msg_count.must_equal 0
        @consumer.errors.must_equal 1
      }    
    end
#  end
end