Question

I’m writing test using double/stub, and i want to return me a fake value, but instead i’m getting and fake value and real value. Here is my controller and spec files, model has nothing in it. Any ideas what am i doing wrong? My guess is i’m doing it completely wrong. P.s. i’m kinda new to spec and mock/stub things

controller:

def destroy
    uri = URI('example.com')
    request_params = {'requestId' => @session.id, 
      'merchantId' => MERCHANTID, 
      'locale' => LOCALE, 
      'partnerId' => PARTNERID, 
      'sessionId' => params[:id]
    }

   Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https') do |http|
      request = Net::HTTP::Post.new uri.request_uri
      request.set_form_data(request_params)
      #request.content_type = 'application/x-www-form-urlencoded'
      response = http.request request # Net::HTTPResponse object
      json = ActiveSupport::JSON.decode(response.body)
      puts '<<<<<<<<<'
      puts json
      if json['expireSessionRes']['isError'] == false
        render :json => {:status => 'ok', :message => 'logged out'}
      else
        render :json => {:status => 'failed', :message => 'logout failed'}
      end
    end

spec file:

it "should correctly return isError false if logout was sucessful" do
    SID = "123"
    @data3 = {:id => SID}  
    delete :destroy, default_rest_params.merge(@data3)
    response = double('http.request')
    response.stub!(:body => '{"expireSessionRes"=>{"requestId"=>"72", "sessionId"=>"123", "isError"=>false, "desc"=>""}}')
    puts response.body


  end

receiving:

{"expireSessionRes"=>{"requestId"=>"94", "isError"=>true, "desc"=>"Session exipred", "errorCode"=>"-10011"}}
{"expireSessionRes"=>{"requestId"=>"72", "sessionId"=>"123", "isError"=>false, "desc"=>""}}

first comes from controller
second from stub

Answer 1

So the thing with mocking and stubbing is, you have to hook your mock objects up to your real code somehow… the double('http.request') bit just creates a mock object called “http.request”, it doesn’t make http.request return this object.

What you need to do is stub the request method to return the mock response. But it’s going to be pretty difficult to inject a mock, because you don’t have access to the http object in the block from your tests.

Difficulty testing code is often a good sign that you need to refactor your code.

The simplest thing would be to replace the whole Net::HTTP.start thing with a single line

response = Net::HTTP.post_form(uri, request_params)

and then you can test it by doing

remote_response = double('remote_response', body: '...')
Net::HTTP.stub(:post_form).and_return(remote_response)

delete :destroy, ...

response.should whatever

(I assume you’re in a controller spec and you’re going to need the response object that RSpec provides, so your mock can’t be stored in a variable called response).

But that is just glossing over the more important point that you should be extracting your remote service interaction out into a dedicated class and testing that separately, it doesn’t belong in the controller.

Hope that helps!