Send notification emails to the "project", and put people in Cc

This fixes email threading in Mail.app, that doesn't like when a thread
doesn't have stable recipients.

For instance, here is a possible sender-recipient combinations before:

From: A
To: Me
New issue

From: B
To: Me
Reply on new issue

From: A
To: Me
Another reply

Mail.app doesn't see B as a participant to the original email thread,
and decides to break the thread: it will group all messages from A
together, and separately all messages from B.

This commit makes the thread look like this:

From: A
To: gitlab/project
Cc: Me
New issue

From: B
To: gitlab/project
Cc: Me
Reply on new issue

From: A
To: gitlab/project
Cc: Me
Another reply

Mail.app sees a common recipient, and group the thread correctly.

app/mailers/emails/groups.rb

@@ -4,7 +4,7 @@ module Emails
       @membership = UsersGroup.find(user_group_id)
       @group = @membership.group
       @target_url = group_url(@group)
-      mail(to: @membership.user.email,
+      mail(cc: @membership.user.email,
            subject: subject("Access to group was granted"))
     end
   end

app/mailers/emails/issues.rb

@@ -6,7 +6,7 @@ module Emails
       @target_url = project_issue_url(@project, @issue)
       set_message_id("issue_#{issue_id}")
       mail(from: sender(@issue.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@issue.title} (##{@issue.iid})"))
     end
 
@@ -17,7 +17,7 @@ module Emails
       @target_url = project_issue_url(@project, @issue)
       set_reference("issue_#{issue_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@issue.title} (##{@issue.iid})"))
     end
 
@@ -28,7 +28,7 @@ module Emails
       @target_url = project_issue_url(@project, @issue)
       set_reference("issue_#{issue_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@issue.title} (##{@issue.iid})"))
     end
 
@@ -40,7 +40,7 @@ module Emails
       @target_url = project_issue_url(@project, @issue)
       set_reference("issue_#{issue_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@issue.title} (##{@issue.iid})"))
     end
   end

app/mailers/emails/merge_requests.rb

@@ -6,7 +6,7 @@ module Emails
       @target_url = project_merge_request_url(@project, @merge_request)
       set_message_id("merge_request_#{merge_request_id}")
       mail(from: sender(@merge_request.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@merge_request.title} (##{@merge_request.iid})"))
     end
 
@@ -17,7 +17,7 @@ module Emails
       @target_url = project_merge_request_url(@project, @merge_request)
       set_reference("merge_request_#{merge_request_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@merge_request.title} (##{@merge_request.iid})"))
     end
 
@@ -28,7 +28,7 @@ module Emails
       @target_url = project_merge_request_url(@project, @merge_request)
       set_reference("merge_request_#{merge_request_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@merge_request.title} (##{@merge_request.iid})"))
     end
 
@@ -38,7 +38,7 @@ module Emails
       @target_url = project_merge_request_url(@project, @merge_request)
       set_reference("merge_request_#{merge_request_id}")
       mail(from: sender(updated_by_user_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@merge_request.title} (##{@merge_request.iid})"))
     end
   end

app/mailers/emails/notes.rb

@@ -6,7 +6,7 @@ module Emails
       @project = @note.project
       @target_url = project_commit_url(@project, @commit, anchor: "note_#{@note.id}")
       mail(from: sender(@note.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@commit.title} (#{@commit.short_id})"))
     end
 
@@ -17,7 +17,7 @@ module Emails
       @target_url = project_issue_url(@project, @issue, anchor: "note_#{@note.id}")
       set_reference("issue_#{@issue.id}")
       mail(from: sender(@note.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@issue.title} (##{@issue.iid})"))
     end
 
@@ -28,7 +28,7 @@ module Emails
       @target_url = project_merge_request_url(@project, @merge_request, anchor: "note_#{@note.id}")
       set_reference("merge_request_#{@merge_request.id}")
       mail(from: sender(@note.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("#{@merge_request.title} (##{@merge_request.iid})"))
     end
 
@@ -37,7 +37,7 @@ module Emails
       @project = @note.project
       @target_url = project_wall_url(@note.project, anchor: "note_#{@note.id}")
       mail(from: sender(@note.author_id),
-           to: recipient(recipient_id),
+           cc: recipient(recipient_id),
            subject: subject("Note on wall"))
     end
   end

app/mailers/emails/projects.rb

@@ -4,7 +4,7 @@ module Emails
       @users_project = UsersProject.find user_project_id
       @project = @users_project.project
       @target_url = project_url(@project)
-      mail(to: @users_project.user.email,
+      mail(cc: @users_project.user.email,
            subject: subject("Access to project was granted"))
     end
 
@@ -12,7 +12,7 @@ module Emails
       @user = User.find user_id
       @project = Project.find project_id
       @target_url = project_url(@project)
-      mail(to: @user.email,
+      mail(cc: @user.email,
            subject: subject("Project was moved"))
     end
 
@@ -30,7 +30,7 @@ module Emails
       end
 
       mail(from: sender(author_id),
-           to: recipient,
+           cc: recipient,
            subject: subject("New push to repository"))
     end
   end

app/mailers/notify.rb

 class Notify < ActionMailer::Base
+  include ActionDispatch::Routing::PolymorphicRoutes
+
   include Emails::Issues
   include Emails::MergeRequests
   include Emails::Notes
@@ -16,6 +18,7 @@ class Notify < ActionMailer::Base
   default_url_options[:script_name] = Gitlab.config.gitlab.relative_url_root
 
   default from: Proc.new { default_sender_address.format }
+  default to:   Proc.new { project_sender_address.format }
   default reply_to: "noreply@#{Gitlab.config.gitlab.host}"
 
   # Just send email with 2 seconds delay
@@ -32,6 +35,17 @@ class Notify < ActionMailer::Base
     address
   end
 
+  # The default email address to send emails to. Includes the project name if possible.
+  def project_sender_address
+    if @project
+      address = default_sender_address
+      address.display_name = @project.name_with_namespace
+      address
+    else
+      default_sender_address
+    end
+  end
+
   # Return an email address that displays the name of the sender.
   # Only the displayed name changes; the actual email address is always the same.
   def sender(sender_id)

spec/mailers/notify_spec.rb

@@ -10,7 +10,7 @@ describe Notify do
 
   shared_examples 'a multiple recipients email' do
     it 'is sent to the given recipient' do
-      should deliver_to recipient.email
+      should cc_to recipient.email
     end
   end
 
@@ -141,7 +141,7 @@ describe Notify do
         end
 
         it 'is sent to the assignee' do
-          should deliver_to assignee.email
+          should cc_to assignee.email
         end
       end
 
@@ -394,7 +394,7 @@ describe Notify do
         end
 
         it 'is sent to the given recipient' do
-          should deliver_to recipient.email
+          should cc_to recipient.email
         end
 
         it 'contains the message from the note' do
@@ -538,7 +538,7 @@ describe Notify do
     end
 
     it 'is sent to recipient' do
-      should deliver_to 'devs@company.name'
+      should cc_to 'devs@company.name'
     end
 
     it 'has the correct subject' do

spec/services/issues/close_service_spec.rb

@@ -22,7 +22,7 @@ describe Issues::CloseService do
 
       it 'should send email to user2 about assign of new issue' do
         email = ActionMailer::Base.deliveries.last
-        email.to.first.should == user2.email
+        email.cc.first.should == user2.email
         email.subject.should include(issue.title)
       end
 

spec/services/issues/update_service_spec.rb

@@ -31,7 +31,7 @@ describe Issues::UpdateService do
 
       it 'should send email to user2 about assign of new issue' do
         email = ActionMailer::Base.deliveries.last
-        email.to.first.should == user2.email
+        email.cc.first.should == user2.email
         email.subject.should include(issue.title)
       end
 

spec/services/merge_requests/close_service_spec.rb

@@ -22,7 +22,7 @@ describe MergeRequests::CloseService do
 
       it 'should send email to user2 about assign of new merge_request' do
         email = ActionMailer::Base.deliveries.last
-        email.to.first.should == user2.email
+        email.cc.first.should == user2.email
         email.subject.should include(merge_request.title)
       end
 

spec/services/merge_requests/update_service_spec.rb

@@ -31,7 +31,7 @@ describe MergeRequests::UpdateService do
 
       it 'should send email to user2 about assign of new merge_request' do
         email = ActionMailer::Base.deliveries.last
-        email.to.first.should == user2.email
+        email.cc.first.should == user2.email
         email.subject.should include(merge_request.title)
       end