vkurennov/controller_macros.rb

## controller_macros.rb
module ControllerHelpers
  def login(user)
    @request.env['devise.mapping'] = Devise.mappings[:user]
    sign_in user
  end
end

## rails_helper.rb
config.include ControllerHelpers, type: :controller

## some_spec.rb
describe SomeController do
  let(:user) { create(:user) }
  before do
    login(user)
    # ...
  end
end
	module ControllerHelpers
	def login(user)
	@request.env['devise.mapping'] = Devise.mappings[:user]
	sign_in user
	end
	end
	describe SomeController do
	let(:user) { create(:user) }
	before do
	login(user)
	# ...
	end
	end