test example

test_example

# 11.6.12

# Jack Dorsey - creator of Twitter

# gem 'rspec'
# bundle
# rails g rspec: install
# in spec, create new folder, models
# rails g test_unit: model Song #=> didn't work as expected
# create songs_spec.rb

require 'spec_helper'

describe Song do
  context '.add_genre' do
    let(:song){Song.create(:name = "Thriller")}
    let(:genre){Genre.create(:name => "Pop")}

    it "should add a genre" do
      song.add_genre(genre)
      song.genres.should include(genre)
    end

    it "should return the newly added genre" do
      song.add_genre(genre).should ==genre
  end

    it "should accept a genre name" do
      song.add_genre("Pop")
      song.genres.find_by_name("Pop").should be_true`
    end
end

rake spec

def add_genre(genre)
  genre = Genre.create(:name => genre) if genre.is_str?
  self.song_genres.create(:genre => genre).genre
end

# each test is run independently in rspec
# anything that happens in a transaction are dependent on each other.  therefore, it begins a transaction,
# let's say inserts into songs, and genres, but then it fails
# so it rollsback from where it began