Add date range to milestone changed emails

Also refactored issues and MRs to use the same email template file

app/mailers/emails/issues.rb

@@ -56,7 +56,9 @@ module Emails
 
       @milestone = milestone
       @milestone_url = milestone_url(@milestone)
-      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, recipient_id, reason))
+      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, recipient_id, reason).merge({
+        template_name: 'changed_milestone_email'
+      }))
     end
 
     def issue_status_changed_email(recipient_id, issue_id, status, updated_by_user_id, reason = nil)

app/mailers/emails/merge_requests.rb

@@ -51,7 +51,9 @@ module Emails
 
       @milestone = milestone
       @milestone_url = milestone_url(@milestone)
-      mail_answer_thread(@merge_request, merge_request_thread_options(updated_by_user_id, recipient_id, reason))
+      mail_answer_thread(@merge_request, merge_request_thread_options(updated_by_user_id, recipient_id, reason).merge({
+        template_name: 'changed_milestone_email'
+      }))
     end
 
     def closed_merge_request_email(recipient_id, merge_request_id, updated_by_user_id, reason = nil)

app/mailers/notify.rb

@@ -16,6 +16,7 @@ class Notify < BaseMailer
   include Emails::AutoDevops
   include Emails::RemoteMirrors
 
+  helper MilestonesHelper
   helper MergeRequestsHelper
   helper DiffHelper
   helper BlobHelper

app/views/notify/changed_milestone_email.html.haml

@@ -1,3 +1,5 @@
 %p
   Milestone changed to
   %strong= link_to(@milestone.name, @milestone_url)
+  - if date_range = milestone_date_range(@milestone)
+    = "(#{date_range})"

app/views/notify/changed_milestone_email.text.erb

@@ -0,0 +1 @@
+Milestone changed to <%= @milestone.name %><% if date_range = milestone_date_range(@milestone) %> (<%= date_range %>)<% end %> ( <%= @milestone_url %> )

app/views/notify/changed_milestone_issue_email.text.erb

@@ -1 +0,0 @@
-Milestone changed to <%= @milestone.name %> ( <%= @milestone_url %> )

app/views/notify/changed_milestone_merge_request_email.html.haml

@@ -1,3 +0,0 @@
-%p
-  Milestone changed to
-  %strong= link_to(@milestone.name, @milestone_url)

app/views/notify/changed_milestone_merge_request_email.text.erb

@@ -1 +0,0 @@
-Milestone changed to <%= @milestone.name %> ( <%= @milestone_url %> )

spec/views/notify/changed_milestone_email.html.haml_spec.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'notify/changed_milestone_email.html.haml' do
+  let(:milestone) { create(:milestone, title: 'some-milestone') }
+  let(:milestone_link) { milestone_url(milestone) }
+
+  before do
+    assign(:milestone, milestone)
+    assign(:milestone_url, milestone_link)
+  end
+
+  context 'milestone without start and due dates' do
+    it 'renders without date range' do
+      render
+
+      expect(rendered).to have_content('Milestone changed to some-milestone', exact: true)
+      expect(rendered).to have_link('some-milestone', href: milestone_link)
+    end
+  end
+
+  context 'milestone with start and due dates' do
+    before do
+      milestone.update(start_date: '2018-01-01', due_date: '2018-12-31')
+    end
+
+    it 'renders with date range' do
+      render
+
+      expect(rendered).to have_content('Milestone changed to some-milestone (Jan 1, 2018–Dec 31, 2018)', exact: true)
+      expect(rendered).to have_link('some-milestone', href: milestone_link)
+    end
+  end
+end