books_controller.rb

require 'spec_helper'


describe BooksController do
  before :each do
    mock_model("Book")
  end

  describe "GET 'new'" do
    before :each do
      get :new
    end

    it "assigns a new Book to @book" do
      assigns(:book).should_not be_nil
      assigns(:book).class.should eq(Book)
    end
  end
  
  describe "GET 'index" do
    before :each do
      get :index
    end

    it "assigns an array of Books called @books" do
      assigns(:books).should_not be_nil
      assigns(:books).class.should eq(Array)
      assigns(:books)[0].class.should eq(Book)
    end
  end

end

books_controller_spec.rb

class BooksController < ApplicationController
  def new
    @book = Book.new
  end

  def create
    redirect_to books_path
  end

  def index
    @books = Book.all
  end
end