Add extended registrar's info to "pending_update_request_for_old_registrant" mailer

#180

spec/mailers/domain_mailer_spec.rb

@@ -1,6 +1,49 @@
 require 'rails_helper'
 
 RSpec.describe DomainMailer do
+  describe '#pending_update_request_for_old_registrant' do
+    let(:domain) { instance_spy(Domain, name: 'test.com') }
+    let(:registrant) { instance_spy(Registrant, email: 'registrant@test.com') }
+    let(:domain_presenter) { instance_spy(DomainPresenter) }
+    let(:registrar_presenter) { instance_spy(RegistrarPresenter) }
+    let(:registrant_presenter) { instance_spy(RegistrantPresenter) }
+    subject(:message) { described_class.pending_update_request_for_old_registrant(domain: domain,
+                                                                                  registrant: registrant,
+    ) }
+
+    before :example do
+      expect(DomainPresenter).to receive(:new).and_return(domain_presenter)
+      expect(RegistrarPresenter).to receive(:new).and_return(registrar_presenter)
+      expect(RegistrantPresenter).to receive(:new).and_return(registrant_presenter)
+    end
+
+    it 'has sender' do
+      expect(message.from).to eq(['noreply@internet.ee'])
+    end
+
+    it 'has registrant email as a recipient' do
+      expect(message.to).to match_array(['registrant@test.com'])
+    end
+
+    it 'has subject' do
+      subject = 'Kinnitustaotlus domeeni test.com registreerija vahetuseks' \
+                ' / Application for approval for registrant change of test.com'
+
+      expect(message.subject).to eq(subject)
+    end
+
+    it 'has confirmation url' do
+      allow(domain).to receive(:id).and_return(1)
+      expect(domain).to receive(:registrant_verification_token).and_return('test')
+      url = registrant_domain_update_confirm_url(domain, token: 'test')
+      expect(message.body.parts.first.decoded).to include(url)
+    end
+
+    it 'sends message' do
+      expect { message.deliver! }.to change { ActionMailer::Base.deliveries.count }.by(1)
+    end
+  end
+
   describe '#pending_deleted' do
     let(:domain) { instance_spy(Domain, name: 'test.com') }
     let(:registrant) { instance_spy(Registrant, email: 'registrant@test.com') }