Question

How can I setup the following models/specs for mocking in my controller specs.

Here are the models

class User < ActiveRecord::Base
  has_many :favorites
end

class Favorite < ActiveRecord::Base
  belongs_to :user
  belongs_to :place
end

class Place < ActiveRecord::Base
  has_many :favorites, :as => :favorable
end

Then at some point a place will be checked to see if it’s currently a favorite

@favorite = @current_user.favorites.find_by_place_id(@place.id)

Now, I want to mock a user for some examples

it "should be success" do
  user = double("User")
  user.stub(:favorites)
  get :show, :id => "1081651"
  response.should be_success
end

But, I end up with

undefined method `find_by_place_id' for nil:NilClass

What can I do with :favorites to help it pass. Since the dynamic finder is used, I’m not sure how to properly mock that up.

Answer 1

Use null object stub, which will ignore all unexpected messages:

user.stub(:favorites).and_return(double.as_null_object)

Another way is to use stub_chain method:

user.stub_chain(:favorites, :find_by_place_id)