Example on how to mock out an API call using RSpec and EM:Http

spec1.rb

before :each do
  @url = 'http://sns.us-east-1.amazonaws.com:80/?Action=ListTopics&Signature=ItTAjeexIPC43pHMZLCL7utnpK8j8AbTUZ3KGUSMzNc%3D&AWSAccessKeyId=123456&Timestamp=123&SignatureVersion=2&SignatureMethod=HmacSHA256'

  EventMachine::MockHttpRequest.reset_registry!
  EventMachine::MockHttpRequest.reset_counts!
  EventMachine::MockHttpRequest.pass_through_requests = false #set to false to not hit the actual API endpoint
     
end

it 'should be able to access the API endpoint' do
  EventMachine::MockHttpRequest.use {
        data = <<-RESPONSE.gsub(/^ +/, '')
          HTTP/1.0 200 OK
          Date: Mon, 16 Nov 2009 20:39:15 GMT
          Expires: -1
          Cache-Control: private, max-age=0
          Content-Type: text/html; charset=ISO-8859-1
          Via: 1.0 .:80 (squid)
          Connection: close

          This is the response back from the server; fill in as you deem fit
        RESPONSE
        
        EventMachine::MockHttpRequest.register(@url,:get,{},data)
        
        EM.run{
          d = < my method here >
          d.callback{
            EM::HttpRequest.count(@url, :get).should == 1
            EM.stop
          }
          d.errback{|error|
            EM.stop
          }
        }

      } #end EM:MockHttpRequest block
end