Unable to stub helper method with rspec

Question

I am trying to stub a method on a helper that is defined in my controller. For example:

class ApplicationController < ActionController::Base
  def current_user
    @current_user ||= authenticated_user_method
  end
  helper_method :current_user
end

module SomeHelper
  def do_something
    current_user.call_a_method
  end
end

In my Rspec:

describe SomeHelper
  it "why cant i stub a helper method?!" do
    helper.stub!(:current_user).and_return(@user)
    helper.respond_to?(:current_user).should be_true # Fails
    helper.do_something # Fails 'no method current_user'
  end
end

In spec/support/authentication.rb

module RspecAuthentication
  def sign_in(user)
    controller.stub!(:current_user).and_return(user)
    controller.stub!(:authenticate!).and_return(true)

    helper.stub(:current_user).and_return(user) if respond_to?(:helper)
  end
end

RSpec.configure do |config|
  config.include RspecAuthentication, :type => :controller
  config.include RspecAuthentication, :type => :view
  config.include RspecAuthentication, :type => :helper
end

I asked a similar question here, but settled on a work around. This strange behavior has creeped up again and I would like to understand why this doesnt work.

UPDATE: I have found that calling controller.stub!(:current_user).and_return(@user) before helper.stub!(...) is what is causing this behavior. This is easy enough to fix in spec/support/authentication.rb, but is this a bug in Rspec? I dont see why it would be expected to not be able to stub a method on a helper if it was already stubbed on a controller.

Answer 1

Try this, it worked for me:

describe SomeHelper
  before :each do
    @helper = Object.new.extend SomeHelper
  end

  it "why cant i stub a helper method?!" do
    @helper.stub!(:current_user).and_return(@user)
    # ...
  end
end

The first part is based on this reply by the author of RSpec, and the second part is based on this Stack Overflow answer.