gistfile1.rb

class Video < ActiveRecord::Base
  has_many :video_locations
  has_many :locations, :through => :video_locations
  attr_accessible :title, :date, :url

  validate :validates_presence_of_locations

  def validates_presence_of_locations
    errors.add(:locations, "must have at least one video") if
      locations.length < 1
  end

  validates_presence_of :title, :date, :url
end


# Tests which are passing
  before(:each) do
    @attr = {
      :title    => "Title",
      :date     => DateTime.now,
      :url      => 'http://youtube.com',
      :location => Location.new,
      :people   => Person.new
    }
  end

  it "should require a location" do
    no_location_video = Video.new(@attr.merge(:location => nil))
    no_location_video.should_not be_valid
  end
     
  it "should require a person" do
    no_person_video = Video.new(@attr.merge(:people => nil))
    no_person_video.should_not be_valid
  end