I’ve been playing with block helpers for some time now, and I love them for their semantic goodness and clarity. I know that Rails 2 has an assert_email method, which plays nicely with assert_select assert_select_email method. However, as far as I could tell, this doesn’t allow you to assert any of the headers such as to, from, etc.

Enter assert_emails_sent:

  def test_send_crash_data
    device_id = 2
    assert_email_sent :to => AdminNotifier::CLIENT_CRASH_EMAIL,
                      :from => AdminNotifier::SYSTEM_EMAIL,
                      :subject => "Application crashed.",
                      :body => /device id #{device_id} crashed.+whoops I crashed/ do
      AdminNotifier.deliver_send_crash_data('whoops I crashed', device_id)                      
    end
  end

• One cool feature is that the values of :to and :from will be automagically sent #email, so you can just say :to => @user, as long as @user.responds_to?(:email).

• Another bonus feature is that you can use either strings or regexps.

grab the code here.