Stub devise authentication in controller specs with multiple scopes

controller_helpers.rb

# Usage:
#   fake_sign_in
#   fake_sign_in(@user)
#   fake_sign_in(@admin)
#   fake_sign_in(:admin)
#   fake_sign_in(@some_object, :scope => :user)

#   fake_sign_out
#   fake_sign_out :admin
module ControllerHelpers
  
  def fake_sign_in(resource_or_scope = :user, options = {})
    if resource_or_scope.is_a?(Symbol)
      scope = resource_or_scope
      resource = double(resource_or_scope)
    else
      resource = resource_or_scope
      scope = options[:scope] || resource.class.to_s.underscore
    end
    # Since we have multiple scopes we need to check if scope option provided to
    # authenticate! matches scope that we are logging in
    allow(request.env['warden']).to receive(:authenticate!) do |options|
      if options[:scope].to_sym == scope.to_sym
        resource
      else
        throw :warden, :scope => scope
      end
    end
    allow(controller).to receive("current_#{scope}").and_return(resource)
  end

  def fake_sign_out(scope = :user)
    allow(request.env['warden']).to receive(:authenticate!).and_throw(:warden, {:scope => scope})
    allow(controller).to receive("current_#{scope}").and_return(nil)
  end
  
end

RSpec.configure do |config|
  config.include Devise::TestHelpers, :type => :controller
  config.include ControllerHelpers, :type => :controller
end

Very nice job! With the other solution posted on the devise wiki, I got this warning:

An expectation of :authenticate! was set on nil. Called from 
/spec/support/controller_macros.rb:25:in `sign_in'. Use allow_message_expectations_on_nil to disable warnings.