Chef Infrastructure errata

gistfile1.rb

require 'chefspec'
describe 'my_cookbook::default' do

  let(:chef_run) { ChefSpec::ChefRunner.new(platform:'ubuntu', version:'12.04') }

  it 'creates a greetings file, containing the platform name' do
    chef_run.converge(described_recipe)
    expect(chef_run).to create_file_with_content('/tmp/greeting.txt','Hello! ubuntu!')
  end

  it 'uses a node attribute as greeting text' do
       chef_run.node.override['my_cookbook']['greeting'] = "Go!"
       chef_run.converge(described_recipe)
       expect(chef_run).to create_file_with_content('/tmp/greeting.txt','Go! ubuntu!')
  end

end

Thanks a lot for finding this and sorry for any inconvenience it may have caused you.
The errata should go online on packtpub.com soon.