controller spec example with cancan

attendances_controller.rb

class AttendancesController < ApplicationController
  before_filter :authenticate_user!
  load_and_authorize_resource

  def show
  end

  def update
    @attendance.update_attributes params[:attendance]
    redirect_to root_path
  end

  def create
    @attendance.save
    redirect_to :back
  end
end

attendances_controller_spec.rb

require 'spec_helper'

describe AttendancesController do

  context "logged in" do
    let(:user) {FactoryGirl.create(:user)}
    before (:each) do
      sign_in user
    end

    context "given an attendance" do
      let(:attendance) {FactoryGirl.create(:attendance, :user => user)}
      describe "GET 'show'" do
        it "authorizes access" do
          ability = Object.new
          ability.extend(CanCan::Ability)
          controller.stub!(:current_ability).and_return(ability)

          ability.should_receive(:can?)
          get :show, :id => attendance.id
        end

        context "shared" do
          before(:each) do
            get :show, :id => attendance.id
          end

          it {should respond_with(:success)}
          it {should render_template(:show)}
          it {should assign_to(:attendance).with(attendance)}
        end # shared
      end # GET 'show'

      describe "PUT 'update'" do
        before(:each) do
          request.env["HTTP_REFERER"] = root_path
        end

        it "authorizes access" do
          ability = Object.new
          ability.extend(CanCan::Ability)
          controller.stub!(:current_ability).and_return(ability)

          ability.should_receive(:can?)
          put :update, :id => attendance.id, :attendance => {}
        end

        context "with valid params" do
          before(:each) do
            Attendance.stub(:find).and_return(attendance)
            attendance.stub(:valid?).and_return(true)
          end

          it "updates attedance" do
            attendance.should_receive(:update_attributes).and_return(true)
            put :update, :id => attendance.id, :attendance => {}, :format => :js
          end
        end
      end # PUT 'update'
    end # attendance

    context "POST 'create'" do
      it "authorizes access" do
        ability = Object.new
        ability.extend(CanCan::Ability)
        controller.stub!(:current_ability).and_return(ability)

        ability.should_receive(:can?)
        post :create, :attendance => {}
      end
    end
  end # logged in
end