notifier_spec.rb

describe 'Notifier' do
  before do
    SMS.stub(:deliver)
    Expense.stub(:create)                                                                                                                                                         

    @user = double 'user', mobile_number: '1234'
    @message = 'hello'

    Notifier.notify(@user, @message)
  end

  it 'delivers SMS' do
    SMS.should have_received(:deliver).with(@user.mobile_number, @message)
  end  

  it 'records SMS expense' do
    Expense.should have_received(:create).with(:sms)
  end  
end