RSpec for acts_as_taggable

Requirements:

An empty post
- should be valid
- should have no tags
- should allow setting tags

A post with tags
- should show tags
- should be listed as tagged

Implementation:

class Post < ActiveRecord::Base
    acts_as_taggable
end

RSpec:

describe "An empty post" do
  before(:each) do
    @post = Post.new
  end

  it "should be valid" do
    @post.should be_valid
  end
  
  it "should have no tags" do
    @post.tags.should be_empty
  end
  
  it "should allow setting tags" do
    @post.tag_list = "tdd, rails"
    @post.save
    @post.tags.should_not be_empty
  end
end

describe "A post with tags" do
  before(:each) do
    @post = Post.new(:tag_list=>"tdd, python, rails")
    @post.save
  end
  
  it "should show tags" do
    @post.tag_list.names.should == ["tdd", "python", "rails"] 
  end
  
  it "should be listed as tagged" do
    Post.find_tagged_with('tdd').should == [@post]
  end
end

More details:
http://agilewebdevelopment.com/plugins/acts_as_taggable_on_steroids