How to stub ApplicationController method in request spec - ruby-on-rails

Question

I am needing to stub the response of a current_user method in an Rspec/capybara request spec. The method is defined in ApplicationController and is using helper_method. The method should simply return a user id. Within the test, I'd like this method to return the same user id each time.
Alternatively, I could fix my problem by setting session[:user_id] in the spec (which is what current_user returns)... but that doesn't seem to work either.
Are either of these possible?
Edit:
Here is what I've got (it is not working. It just runs the normal current_user method).
require 'spec_helper'
describe "Login" do
before(:each) do
ApplicationController.stub(:current_user).and_return(User.first)
end
it "logs in" do
visit '/'
page.should have_content("Hey there user!")
end
end
Also not working:
require 'spec_helper'
describe "Login" do
before(:each) do
#mock_controller = mock("ApplicationController")
#mock_controller.stub(:current_user).and_return(User.first)
end
it "logs in" do
visit '/'
page.should have_content("Hey there user!")
end
end

Answer 1

skalee seems to have provided the correct answer in the comment.
If the method you're trying to stub is an instance method (most likely) and not a class method then you need use:
ApplicationController.any_instance.stub(:current_user)

Answer 2

Here are a couple of examples of the basic form.
controller.stub(:action_name).and_raise([some error])
controller.stub(:action_name).and_return([some value])
In your particular case, I believe the proper form would be:
controller.stub(:current_user).and_return([your user object/id])
Here's a full working example from a project I work on:
describe PortalsController do
it "if an ActionController::InvalidAuthenticityToken is raised the user should be redirected to login" do
controller.stub(:index).and_raise(ActionController::InvalidAuthenticityToken)
get :index
flash[:notice].should eql("Your session has expired.")
response.should redirect_to(portals_path)
end
end
To explain my full example, basically what this does is verify that, when an ActionController::InvalidAuthenticityToken error is raised anywhere in the app, that a flash message appears, and the user is redirected to the portals_controller#index action. You can use these forms to stub out and return specific values, test an instance of a given error being raised, etc. There are several .stub(:action_name).and_[do_something_interesting]() methods available to you.
Update (after you added your code): per my comment, change your code so it reads:
require 'spec_helper'
describe "Login" do
before(:each) do
#mock_controller = mock("ApplicationController")
#mock_controller.stub(:current_user).and_return(User.first)
end
it "logs in" do
visit '/'
page.should have_content("Hey there user!")
end
end

Answer 3

This works for me and gives me a #current_user variable to use in tests.
I have a helper that looks like this:
def bypass_authentication
current_user = FactoryGirl.create(:user)
ApplicationController.send(:alias_method, :old_current_user, :current_user)
ApplicationController.send(:define_method, :current_user) do
current_user
end
#current_user = current_user
end
def restore_authentication
ApplicationController.send(:alias_method, :current_user, :old_current_user)
end
And then in my request specs, I call:
before(:each){bypass_authentication}
after(:each){restore_authentication}

Answer 4

For anyone else who happens to need to stub an application controller method that sets an ivar (and was stymied by endless wanking about why you shouldn't do that) here's a way that works, with the flavour of Rspec circa October 2013.
before(:each) do
campaign = Campaign.create!
ApplicationController.any_instance.stub(:load_campaign_singleton)
controller.instance_eval{#campaign = campaign}
#campaign = campaign
end
it stubs the method to do nothing, and sets the ivar on rspec's controller instance, and makes it available to the test as #campaign.

Answer 5

For Rspec 3+ the new api is:
For a controller test, nice and short:
allow(controller).to receive(:current_user).and_return(#user)
Or for all instances of ApplicationController:
allow_any_instance_of(ApplicationController).to receive(:current_user).and_return(#user)

Answer 6

None of the provided responses worked for me. As in #matt-fordam's original post, I have a request spec, not a controller spec. The test just renders the view without launching a controller.
I resolved this by stubbing the method on the view as described in this other SO post
view.stub(:current_user).and_return(etc)