Allow more mail clients to group emails by thread

* send a 'In-Reply-To' header along the 'References' header
* subject of answers to an existing thread begins with 'Re: '

1 files changed, 27 insertions, 16 deletions

diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index 224b613b477..d7230ec4341 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -22,6 +22,23 @@ describe Notify do
     end
   end
 
+  shared_examples 'an email starting a new thread' do |message_id_prefix|
+    it 'has a discussion identifier' do
+      should have_header 'Message-ID',  /<#{message_id_prefix}(.*)@#{Gitlab.config.gitlab.host}>/
+    end
+  end
+
+  shared_examples 'an answer to an existing thread' do |thread_id_prefix|
+    it 'has a subject that begins with Re: ' do
+      should have_subject /^Re: /
+    end
+
+    it 'has headers that reference an existing thread' do
+      should have_header 'References',  /<#{thread_id_prefix}(.*)@#{Gitlab.config.gitlab.host}>/
+      should have_header 'In-Reply-To', /<#{thread_id_prefix}(.*)@#{Gitlab.config.gitlab.host}>/
+    end
+  end
+
   describe 'for new users, the email' do
     let(:example_site_path) { root_path }
     let(:new_user) { create(:user, email: 'newguy@example.com', created_by_id: 1) }
@@ -153,6 +170,7 @@ describe Notify do
           subject { Notify.new_issue_email(issue.assignee_id, issue.id) }
 
           it_behaves_like 'an assignee email'
+          it_behaves_like 'an email starting a new thread', 'issue'
 
           it 'has the correct subject' do
             should have_subject /#{project.name} \| #{issue.title} \(##{issue.iid}\)/
@@ -161,10 +179,6 @@ describe Notify do
           it 'contains a link to the new issue' do
             should have_body_text /#{project_issue_path project, issue}/
           end
-
-          it 'has the correct message-id set' do
-            should have_header 'Message-ID', "<issue_#{issue.id}@#{Gitlab.config.gitlab.host}>"
-          end
         end
 
         describe 'that are new with a description' do
@@ -179,6 +193,7 @@ describe Notify do
           subject { Notify.reassigned_issue_email(recipient.id, issue.id, previous_assignee.id, current_user) }
 
           it_behaves_like 'a multiple recipients email'
+          it_behaves_like 'an answer to an existing thread', 'issue'
 
           it 'is sent as the author' do
             sender = subject.header[:from].addrs[0]
@@ -201,16 +216,14 @@ describe Notify do
           it 'contains a link to the issue' do
             should have_body_text /#{project_issue_path project, issue}/
           end
-
-          it 'has the correct reference set' do
-            should have_header 'References', "<issue_#{issue.id}@#{Gitlab.config.gitlab.host}>"
-          end
         end
 
         describe 'status changed' do
           let(:status) { 'closed' }
           subject { Notify.issue_status_changed_email(recipient.id, issue.id, status, current_user) }
 
+          it_behaves_like 'an answer to an existing thread', 'issue'
+
           it 'is sent as the author' do
             sender = subject.header[:from].addrs[0]
             sender.display_name.should eq(current_user.name)
@@ -232,10 +245,6 @@ describe Notify do
           it 'contains a link to the issue' do
             should have_body_text /#{project_issue_path project, issue}/
           end
-
-          it 'has the correct reference set' do
-            should have_header 'References', "<issue_#{issue.id}@#{Gitlab.config.gitlab.host}>"
-          end
         end
 
       end
@@ -249,6 +258,7 @@ describe Notify do
           subject { Notify.new_merge_request_email(merge_request.assignee_id, merge_request.id) }
 
           it_behaves_like 'an assignee email'
+          it_behaves_like 'an email starting a new thread', 'merge_request'
 
           it 'has the correct subject' do
             should have_subject /#{merge_request.title} \(##{merge_request.iid}\)/
@@ -283,6 +293,7 @@ describe Notify do
           subject { Notify.reassigned_merge_request_email(recipient.id, merge_request.id, previous_assignee.id, current_user.id) }
 
           it_behaves_like 'a multiple recipients email'
+          it_behaves_like 'an answer to an existing thread', 'merge_request'
 
           it 'is sent as the author' do
             sender = subject.header[:from].addrs[0]
@@ -311,6 +322,7 @@ describe Notify do
           subject { Notify.merged_merge_request_email(recipient.id, merge_request.id, merge_author.id) }
 
           it_behaves_like 'a multiple recipients email'
+          it_behaves_like 'an answer to an existing thread', 'merge_request'
 
           it 'is sent as the merge author' do
             sender = subject.header[:from].addrs[0]
@@ -329,10 +341,6 @@ describe Notify do
           it 'contains a link to the merge request' do
             should have_body_text /#{project_merge_request_path project, merge_request}/
           end
-
-          it 'has the correct reference set' do
-            should have_header 'References', "<merge_request_#{merge_request.id}@#{Gitlab.config.gitlab.host}>"
-          end
         end
       end
     end
@@ -410,6 +418,7 @@ describe Notify do
         subject { Notify.note_commit_email(recipient.id, note.id) }
 
         it_behaves_like 'a note email'
+        it_behaves_like 'an answer to an existing thread', 'commits'
 
         it 'has the correct subject' do
           should have_subject /#{commit.title} \(#{commit.short_id}\)/
@@ -428,6 +437,7 @@ describe Notify do
         subject { Notify.note_merge_request_email(recipient.id, note.id) }
 
         it_behaves_like 'a note email'
+        it_behaves_like 'an answer to an existing thread', 'merge_request'
 
         it 'has the correct subject' do
           should have_subject /#{merge_request.title} \(##{merge_request.iid}\)/
@@ -446,6 +456,7 @@ describe Notify do
         subject { Notify.note_issue_email(recipient.id, note.id) }
 
         it_behaves_like 'a note email'
+        it_behaves_like 'an answer to an existing thread', 'issue'
 
         it 'has the correct subject' do
           should have_subject /#{issue.title} \(##{issue.iid}\)/