Simple BDD API for testing asynchronous Ruby/EventMachine code © 2008 Aman Gupta (tmm1)

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

There are two ways to use the Rspec extension. 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

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

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.

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:

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:

• Git repository: github.com/tmm1/em-spec

• Bacon: groups.google.com/group/comp.lang.ruby/browse_thread/thread/30b07b651b0662fd

• Initial announcement: groups.google.com/group/eventmachine/browse_thread/thread/8b4e7ead72f9d013