Testing behavior of before vs. before :each vs before :all

before_spec.rb

require 'spec_helper'

$count = 0
$count_each = 0
$count_all = 0

shared_examples_for "before :each" do 
  it { should == 1 }
  it { should == 2 }
end

describe "before" do 
  before do 
    $count += 1
  end

  subject { $count }
  it_should_behave_like "before :each"
end

describe "before :each" do
  before :each do 
    $count_each += 1
  end

  subject { $count_each }
  it_should_behave_like "before :each"
end

describe "before :all" do 
  before :all do 
    $count_all += 1
  end

  subject { $count_all }
  it { should == 1 }
  it { should == 1 }
end