RSpec捣毁邮件

Question

I have a UserMailDispatcher class whose job it is to delver mail via ActiveMailer based on certain criteria.

I'm trying to test it using RSpec but am coming up short. I would like to somehow stub a test mailer and see if the class properly delivers it. Here's what I have so far:

All my mailers inherit from ApplicationMailer:

application_mailer.rb

class ApplicationMailer < ActionMailer::Base
  append_view_path Rails.root.join('app', 'views', 'mailers')
end

user_mail_dispatcher_spec.rb

require 'rails_helper'

describe UserMailDispatcher do 
  class UserMailer < ApplicationMailer 
    def test_mail
      mail
    end
  end

  it "mails stuff" do
    ???
  end
end

I want to test that the dispatcher can properly queue/deliver mail. However, I cannot seem to call UserMailer.test_mail.deliver_now . I get missing template 'user_mailer/test_mail' I tried adding type: :view to the spec and using stub_template 'user_mailer/test_mail.html.erb' , but I get the same error.

I do have a UserMailer defined but I don't want to test any of its methods here since those are more likely to change.

Any ideas on how to best handle this?

Answer 1

I came across this issue as well when I was testing using a DummyMailer and to get around it I just asked the mail method to return plain text like this:

mail do |format|
  format.text { render plain: "Hello World!" }
end

Here is the documentation for it , scroll down a little bit to find the right section.

Answer 2

Add the required template and test without stubbing by using ActionMailer::Base.deliveries . Here's an example (in minitest) from the guide ( http://guides.rubyonrails.org/testing.html#testing-your-mailers ).

require 'test_helper'

class UserMailerTest < ActionMailer::TestCase
  test "invite" do
    # Send the email, then test that it got queued
    email = UserMailer.create_invite('me@example.com',
                                     'friend@example.com', Time.now).deliver_now
    assert_not ActionMailer::Base.deliveries.empty?

    # Test the body of the sent email contains what we expect it to
    assert_equal ['me@example.com'], email.from
    assert_equal ['friend@example.com'], email.to
    assert_equal 'You have been invited by me@example.com', email.subject
    assert_equal read_fixture('invite').join, email.body.to_s
  end
end

Answer 3

Here is the way how to test that mailer is called with right arguments.

it 'sends email' do
  delivery = double
  expect(delivery).to receive(:deliver_now).with(no_args)

  expect(UserMailer).to receive(:test_mail)
    .with('my_arguments')
    .and_return(delivery)

  UserMailDispatcher.my_function
end