Rails - How do you test ActionMailer sent a specific email in tests

Question

Currently in my tests I do something like this to test if an email is queued to be sent

assert_difference(\'ActionMailer::Base.deliveries.size\', 1) do              


        

Answer 1

Here is the best way I've found to do it.

1) Include the action mailer callbacks plugin like this:

script/plugin install git://github.com/AnthonyCaliendo/action_mailer_callbacks.git

I don't really use the plugin's main features, but it does provide the nice functionality of being able to figure out which method was used to send an email.

2) Now you can put some methods in your test_helper.rb like this:

  def assert_sent(method_name)
    assert sent_num_times(method_name) > 0
  end

  def assert_not_sent(method_name)
    assert sent_num_times(method_name) == 0
  end

  def assert_sent_once(method_name)
    assert sent_num_times(method_name) == 1
  end

  def sent_num_times(method_name)
    count = 0
    @emails.each do |email|
      count += 1 if method_name == email.instance_variable_get("@method_name")
    end
    count
  end

3) Now you can write sweet tests like this:

require 'test_helper'
class MailingTest < ActionController::IntegrationTest

  def setup
    @emails = ActionMailer::Base.deliveries
    @emails.clear
  end

  test "should send a mailing" do
    assert_difference "Mailing.count", 1 do
      feeds(:feed1).generate_mailing
    end

    assert_sent_once "broadcast"
    assert_not_sent "failed_mailing"
  end
end

Here "broadcast" and "mailing_failed" are the names of the methods in my ActionMailer::Base class. These are the ones you normally use by calling Mailer.deliver_broadcast(some_data) or Mailer.deliver_failed_mailing(some_data) etc. That's it!