Trouble with Association Proxies and new/create in rails

Testing RSpec
1

I’m working on some code that uses association proxies. I’m trying to
get away from using fixtures, and move more to mocking and stubbing.
So far, so good, but the methods I cant figure out, even with
extensive googling, are how to simulate the association_proxy.build
method in rails.

I’m on edge rails and edge rspec.

Datawise, a bar has_many suggested_beers, and a suggested_beer belongs
to a bar

suggested_beers_controller

end

private
def find_bar
@bar = Bar.find(params[:bar_id])
end

suggested_beers_controller_spec.rb

This is generated with rspec_scaffold, and i’ve added in the beer_id,
bar_id, and ip_address attributes for stubbing.

@mock_suggested_beer ||= mock_model(SuggestedBeer, stubs)
  get :new, :bar_id => "1"
  response.should render_template('new')
end

it "should create a new suggested_beer" do

SuggestedBeer.should_receive(:new).and_return(mock_suggested_beer)
get :new, :bar_id => “1”
end
“should create a new suggested_beer” fails with this message

Spec::Mocks::MockExpectationError in ‘SuggestedBeersController
responding to GET /bars/1/suggested_beers/new should create a new
suggested_beer’
Mock ‘SuggestedBeer_1016’ received unexpected message :[]= with
(“bar_id”, 1)

I don’t know how to fix this.

I’ve looked at several articles, specifically
http://www.lukeredpath.co.uk/2007/10/18/demeters-revenge
and Attempting to Make Sense of RSpec use - RSpec - Ruby-Forum
but I’m still confused.

Any help is much appreciated!

Sam Granieri, Jr
[email protected]
Chicago, IL

irc (freenode): samgranieri

http://www.samgranieri.com
http://www.beerbin.com

Recommend me at WWR!
http://www.workingwithrails.com/person/7374-sam-granieri

2

On Mon, Jul 7, 2008 at 2:28 AM, Sam Granieri, Jr [email protected]
wrote:

suggested_beers_controller

 format.html

private
bar_id, and ip_address attributes for stubbing.
}.merge(stubs)
it “should render the ‘new’ template” do
“should create a new suggested_beer” fails with this message

Spec::Mocks::MockExpectationError in ‘SuggestedBeersController responding
to GET /bars/1/suggested_beers/new should create a new suggested_beer’
Mock ‘SuggestedBeer_1016’ received unexpected message :[]= with (“bar_id”,
1)

The way I approach this is to stub the object which has the association
proxy to return a mock for the proxy. To do that you have to stub
whatever
method your controller uses to get that object.

In this case, assuming that your controller is setting up @bar in the
obvious way, it would be something like.

it “should create a new suggested_beer” do
suggested_beers = mock(“suggested_beers”)
bar = mock_model(Bar, :suggested_beers => suggested_beers)
Bar.stub!(:find).and_return(bar)
suggested_beer = mock_model(SuggestedBeer, …)

SuggestedBeer.should_receive(:build).with(:blatz)…and_return(mock_suggested_beer)
get :new, :bar_id => “1”, :suggested_beer => :blatz
end

Some would break this down into at least two examples, one just checking
that the build method is called and another checking that it is called
with
the expected paramenters.

–
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/