tasks_controller.rb

class TasksController < ApplicationController
  before_filter :load_user 

  def index
    @tasks = @user.tasks
  end

  def new
    @task = @user.tasks.new
  end
  
  def create
    @task = @user.tasks.new
    if @task.save
      flash[:notice] = "Task Added Successfully!"
      redirect_to user_tasks_path(@user.id)
    else
      render :action => 'new'
    end
  end

  private

  def load_user
    if current_user.id == params[:user_id].to_i
      @user = current_user 
    else
      flash[:notice] = "Sorry but you can't view other people's tasks."
      redirect_to root_path
    end
  end
end

tasks_controller_spec.rb

require 'spec_helper'

describe TasksController do

  before(:each) do
    @user = Factory(:user)
    sign_in @user
    @task = Factory(:task)
    User.stub_chain(:where, :first).and_return(@user)
    controller.stub!(:load_user).and_return(@user)
  end

  #GET Index
  describe "GET Index" do
    
    before(:each) do
      @tasks = 7.times{Factory(:task, :user => @user)}
      @user.stub!(:tasks).and_return(@tasks)
    end
 
    it "should should find all of the tasks owned by a user" do
      @user.should_receive(:tasks).and_return(@tasks)
      get :index, :user_id => @user.id
    end

    it "should assign all of the user's tasks to the view" do
      get :index, :user_id => @user.id
      assigns[:tasks].should be(@tasks)      
    end
  end

  #GET New
  describe "GET New" do

    before(:each) do
      @user.stub_chain(:tasks, :new).and_return(@task)
    end

    it "should return a new Task" do
      @user.tasks.should_receive(:new).and_return(@task)
      get :new, :user_id => @user.id
    end
  end

  #POST Create
  describe "POST Create" do

    before(:each) do
      @user.stub_chain(:tasks, :new).and_return(@task)
    end

    it "should create a new task" do
     @user.tasks.should_receive(:new).and_return(@task)
      post :create, :user_id => @user.id, :task => @task.to_s
    end

    it "saves the task" do
      @task.should_receive(:save)
      post :create, :user_id => @user.id, :task => @task
    end

    context "when the task is saved successfully" do
    
      before(:each) do
        @task.stub!(:save).and_return(true)
      end

      it "should set the flash[:notice] message to 'Task Added Successfully'"do 
        post :create, :user_id => @user.id, :task => @task
        flash[:notice].should == "Task Added Successfully!"
      end

      it "should redirect to the user's task page" do
        post :create, :user_id => @user.id, :task => @task
        response.should redirect_to(user_tasks_path(@user.id))
      end
    end

    context "when the task isn't saved successfully" do
      
      before(:each) do
        @task.stub(:save).and_return(false)
      end

      it "should return to the 'Create New Task' page do" do
        post :create, :user_id => @user.id, :task => @task
        response.should render_template('new')
      end
    end
  end

  it "should attempt to authenticate and load the user who owns the tasks" do
      
    context "when the tasks belong to the currently logged in user" do
    
      it "should set the user instance variable to the currently logged in user" do
        pending 
      end
    
    end

    context "when the tasks belong to another user" do
      
      it "should set the flash[:notice] to 'Sorry but you can't view other people's tasks.'" do
        pending
      end

      it "should redirect to the home page" do
        pending
      end
    end
  end
end