Simple BDD API for testing asynchronous Ruby/EventMachine code

em-spec can be used with either bacon, test unit or rspec.

Rspec

There are two ways to use with the Rspec gem.

To use it as a helper, include EM::SpecHelper in your describe block. You then use the em method to wrap your evented test code.

Inside the em block, you must call done after your expectations. Everything works normally otherwise.

  require "em-spec/rspec"
  describe EventMachine do
    include EM::SpecHelper
  
    it "works normally when not using #em" do
      1.should == 1
    end
  
    it "makes testing evented code easy with #em" do
      em do
        start = Time.now

        EM.add_timer(0.5){
          (Time.now-start).should be_close( 0.5, 0.1 )
          done
        }
      end
    end
  end

The other option is to include EM::Spec in your describe block.

This will patch Rspec so that all of your examples run inside an em block automatically:

  require "em-spec/rspec"
  describe EventMachine do
    include EM::Spec
    
    it "requires a call to #done every time" do
      1.should == 1
      done
    end
    
    it "runs test code in an em block automatically" do
      start = Time.now

      EM.add_timer(0.5){
        (Time.now-start).should be_close( 0.5, 0.1 )
        done
      }
    end
  end

Bacon

The API is identical to Bacon, except that you must explicitly call done after all the current behavior's assertions have been made:

  require 'em-spec/bacon'

  EM.describe EventMachine do

    should 'have timers' do
      start = Time.now

      EM.add_timer(0.5){
        (Time.now-start).should.be.close 0.5, 0.1
        done
      }
    end

    should 'have periodic timers' do
      num = 0
      start = Time.now

      timer = EM.add_periodic_timer(0.5){
        if (num += 1) == 2
          (Time.now-start).should.be.close 1.0, 0.1
          EM.__send__ :cancel_timer, timer
          done
        end
      }
    end

  end

Test::Unit

There are two ways to use the Test::Unit extension.

To use it as a helper, include EM::TestHelper in your test unit class.

You then use the em method to wrap your evented test code.

Inside the em block, you must call done after your expectations. Everything works normally otherwise.

  require 'em-spec/test'

  class EmSpecHelperTest < Test::Unit::TestCase
    include EventMachine::TestHelper
  
    def test_trivial
      em do
        assert_equal 1, 1
        done
      end
    end
  end

The other option is to include EM::Test in your test class.

This will patch Test::Unit so that all of your examples run inside an em block automatically:

  require 'em-spec/test'

  class EmSpecTest < Test::Unit::TestCase
  
    include EventMachine::Test

    def test_timer
      start = Time.now

      EM.add_timer(0.5){
        assert_in_delta 0.5, Time.now-start, 0.1
        done
      }
    end
  end

Resources

• Bacon