answer_spec.rb

require 'spec_helper'

describe Answer do
  describe "in general" do
      before(:all) do
        site = Factory(:site)
        page = Factory(:page)
        @answer = Factory(:answer, :page_id => page.id, :site_id => site.id)
        subject {@answer}
      end

        it { should belong_to(:page) }
        it { should validate_presence_of(:site_id) }
        it { should validate_presence_of(:page_id) }
        it { should respond_to(:published_at) }
        it { should respond_to(:question) }
        it { should respond_to(:answer) }
    end

    describe "create answer" do
      before(:each) do
        @site = Factory(:site)
        @page = Factory(:page)
      end
        
        it "should create a question and answer for site" do
          @answer = Factory.build(:answer, :page_id => @page.id, :question => "Question 1", :site_id => @site.id)
          @answer.question.should include("Question 1")
        end

        it "with page_id should be valid" do
          Factory.build(:answer, :page_id => @page.id, :site_id => @site.id).should be_valid
        end
        
        
        it "without page_id should not be valid" do
          Factory.build(:answer, :site_id => @site.id).should_not be_valid
        end
    end
    
    describe "answer for specified slug" do
      before(:each) do
        site = Factory(:site)
        @page = Factory(:page)
        @page2 = Factory(:page)
        
        @answer = Factory(:answer, :page_id => @page.id, :question => "Question 1", :site_id => site.id)
        @answer2 = Factory(:answer, :page_id => @page2.id, :question => "Question 2", :site_id => site.id)
      end
      
      it "should not include any answer without given parent_slug" do
        Answer.for_parent_id(@page.id).should_not include(@answer2) 
      end

      it "should include any answer that has the given parent_slug" do
        Answer.for_parent_id(@page.id).should include(@answer)
      end
      
    end
    
end

migration.rb

class CreateAnswers < ActiveRecord::Migration
  def self.up
    create_table :answers do |t|
      t.integer :site_id,        :null => false
      t.integer :page_id         :null => false
      t.string :slug
      t.datetime :published_at
      t.string :question
      t.text :answer

      t.timestamps
    end

    add_index :answers, [:parent_slug, :slug], :unique => true
    add_foreign_key(:answers, :sites)    
    
  end

  def self.down
    drop_table :answers
  end
end