Rails 5-测试应用程序邮件

Question

I want to test the mailer in my application to make sure it is doing what I want it to do.

class LessonMailer < ApplicationMailer
   def send_mail(lesson)
      @lesson = lesson
      mail(to: lesson.student.email, 
        subject: 'A lesson has been recorded by your tutor')
   end
end 

This is my test in the spec/mailers directory

require "rails_helper"

RSpec.describe LessonMailer, :type => :mailer do
   describe "lesson" do

     let( :student ){ FactoryGirl.create :user, role: 'student', givenname: 'name', sn: 'sname', email: 'test@sheffield.ac.uk' }
     let( :lesson  ){ FactoryGirl.create :lesson, student_id: 2 }
     let( :mail    ){ LessonMailer.send_mail( lesson ).deliver_now 

     it "renders the headers" do
      expect(mail.subject).to eq("A lesson has been recorded")
      expect(mail.to).to eq(["to@example.ac.uk"])
      expect(mail.from).to eq(["no-reply@example.ac.uk"])
     end

    it "renders the body" do
     expect(mail.body.encoded).to match("A lesson form has been recorded")
    end
  end
end

I want to test that the 'send_mail' method is working the way I want it to however, I am getting this error. How do I go about solving this problem ? Thank you.

 NoMethodError:
   undefined method `email' for nil:NilClass
 # ./app/mailers/lesson_mailer.rb:4:in `send_mail'

Answer 1

So, with FactoryGirl, you just need to instantiate the different objects that you need. Reading your code, it seems clear that a lesson has a student and that students have an email . So go ahead and create everything you need and then call your method. You can do something like this:

# Here's the student factory (for this use case, you'll probably want to make it more general)
FactoryGirl.define do
  factory :user do
    role 'student'
    givenname 'name'
    sn 'sname'
    email 'test@sheffield.ac.uk'
  end
end

# Here's your test
require "rails_helper"

RSpec.describe LessonMailer, :type => :mailer do
  describe "lesson" do
    let( :student ){ create :student, email: 'test_email@example.com' }
    let( :lesson  ){ create :lesson, student: student }
    let( :mail    ){ LessonMailer.send_mail( lesson ) }

    it ' ... ' do
      ...
    end
  end
end

You'll need to let the test environment know that you want the emails to be delivered to the ActionMailer::Base.deliveries array. To do this, make sure that

config.action_mailer.delivery_method = :test

is set in your config/environments/test.rb

One last thing, I'm not sure if you'll need it, but you might have to call the mailer with, .deliver_now .

Like this:

let( :mail ){ LessonMailer.send_mail( lesson ).deliver_now }

... or it may not send. I can't remember off the top.

Let me know how it goes.