Exemplo de como testar Mailers com RSpec

notification_spec.rb

require "spec_helper"

describe Notification do
  describe "idea created" do
    before(:each) do
      @idea = Idea.new({
        :author_name => 'Nome do Usuario',
        :author_email => '[email protected]',
      })
      @idea.stub(:id).and_return(98765)
    end
    
    it "should render successfully" do
      lambda { Notification.idea_created(@idea) }.should_not raise_error
    end
    
    describe "rendered without error" do

      before(:each) do
        @mailer = Notification.idea_created(@idea)
      end

      it "should set correct subject" do
        @mailer.subject.should == "Sua Idea foi Publicada."
      end

      it "should set correct header To" do
        # Ele não coloca as aspas por que não receonhece nenhum caracter UTF-8 (acento)
        @mailer.header['To'].to_s.should == "Nome do Usuario <[email protected]>"
      end

      it "should not have more than one to address" do
        @mailer.to.size.should == 1
      end

      it "should consider CC on recipients address" do
        @mailer.cc.should be_nil
      end

      it "should consider BCC on recipients address" do
        @mailer.bcc.should == ["[email protected]"]
      end

      it "should set correct header From" do
        # Ele coloca as aspas por que reconhece que existe um caracter UTF-8 (acento)
        @mailer.header['From'].to_s.should == "Startup DEV <[email protected]>"
      end

      it "should not have more than one from address" do
        @mailer.from.size.should == 1
      end

      it "should be multipart" do
        @mailer.multipart?.should be_false
      end

      it "should set correct charset" do
        @mailer.charset.should == "UTF-8"
      end

      it "should set correct body for text html" do
        body = @mailer.body
        filename = Rails.root.join('spec','fixtures','mailers','idea_created.html')
        File.open(filename, 'w') {|f| f.write(body) } unless File.exists?(filename)
        body.should == File.read(filename)
      end

      it "should set correct content type" do
        @mailer.content_type.should == "text/html; charset=UTF-8"
      end

      it "should deliver successfully" do
        lambda { Notification.idea_created(@idea).deliver }.should_not raise_error
      end

      describe "and delivered" do

        it "should be added to the delivery queue" do
          lambda { Notification.idea_created(@idea).deliver }.should change(ActionMailer::Base.deliveries,:size).by(1)
        end

      end
      
    end
  end
end