How do I mock models, instances and helpers in a controller spec? - ruby-on-rails

Question

require 'spec_helper'
describe UsersController do
let(:user){ double(User, id: 2, name: "Jimbo", email: 'jimbo#email.com', password: 'passwordhuzzah', password_confirmation: 'passwordhuzzah') }
before do
mock_model("User")
end
describe 'PATCH #update' do
User.should_receive(:find).with(user.id.to_s).and_return user
user.should_receive(:update_attributes).with({ "email" => user.email, "name" => user.name, "password" => user.password, "password_confirmation" => user.password_confirmation })#.and_return true
patch :update, id: user.id, user: { email: user.email, name: user.name, password: user.password, password_confirmation: user.password_confirmation }
flash[:error].should == "could not update user"
response.status.should == 200
end
end
codebase:
def update
#user = User.find(params[:id])
if #user.update_attributes(user_params)
redirect_to #user, flash: { success: 'succesfully updated user' }
else
flash.now[:error] = "could not update user"
render 'edit'
end
end
While the above spec passes (and passes in just 0.05 seconds!) am I doing it correctly? With the mocks above the request, and the 'normal' expectations below it? It seems a bit clumsy. Not only is it hard to read, but if one expectation fails, all of them will appear to fail.
What makes me think I'm doing it wrong is a weird error I'm getting. See the second line of the describe block, where I'm saying the instance of user (user) should have its update_attributes triggered with updated attributes? Note the and_return true method I've commented out. When it's chained on, running the above spec hits me with this stinker:
1) UsersController should_receive
Failure/Error: patch :update, id: user.id, user: { email: user.email, name: user.name, password: user.password, password_confirmation: user.password_confirmation }
NoMethodError:
undefined method `model_name' for RSpec::Mocks::Mock:Class
While this a over my head, I think it's because the user 'instance' isn't actually an instance, just a hash. I thought because I used mock_model and the double inherits from that mocked model, all of the active-record-y stuff such as the 'model_name' method would be set.
Anyway, how should I write this spec properly? I don't want to use FactoryGirl, I want to keep it all contained so my specs are fast and accurately report a fault.

Answer 1

Yes, in this case of controller testing, your basic flow is "normal", except that your innermost code needs to be within an it block (and perhaps is and is just not transcribed properly).
However, you're not making use of the mock_model call, since you're not doing anything with the result. This method doesn't make any fundamental changes to the class whose string name you pass it, it simply creates a mock object that simulates an ActiveRecord instance, which in your case you effectively discard. Like all RSpec doubles, the first parameter is just giving it a name that can be used for error messages and such.
So yes, the reason you're getting the error when you return true is that redirect_to expects #user to be an ActiveRecord instance and while it's not just a Hash as you suggest it might be, it does not have the model_name method it needs.
There are lots of ways to rewrite this, particularly if you want to support both the success and failure cases, but one way that minimizes the changes is (not fully tested):
describe UsersController do
let(:user){ mock_model(User, id: 2, name: "Jimbo", email: 'jimbo#email.com', password: 'passwordhuzzah', password_confirmation: 'passwordhuzzah') }
describe 'PATCH #update' do
it "should fail in this case" do
User.should_receive(:find).with(user.id.to_s).and_return user
user.should_receive(:update_attributes).with({ "email" => user.email, "name" => user.name, "password" => user.password, "password_confirmation" => user.password_confirmation })#.and_return true
patch :update, id: user.id, user: { email: user.email, name: user.name, password: user.password, password_confirmation: user.password_confirmation }
flash[:error].should == "could not update user"
response.status.should == 200
end
end
end