Separate observing of Note and MergeRequests

* Move is_assigned? and is_being_xx? methods to IssueCommonality

  This is behavior merge requests have in common with issues. Moved
  methods to IssueCommonality role. Put specs directly into
  merge_request_spec because setup differs for issues and MRs
  specifically in the "closed" factory to use.

* Add MergeRequestObserver. Parallels IssueObserver in almost every way.

  Ripe for refactoring.

* Rename MailerObserver to NoteObserver

  With merge request observing moved out of MailerObserver, all that
  was left was Note logic. Renamed to NoteObserver, added tests and
  updated application config for new observer names. Refactored
  NoteObserver to use the note's author and not rely on current_user.

* Set current_user for MergeRequestObserver

  IssueObserver and MergeRequestObserver are the only observers that
  need a reference to the current_user that they cannot look up on
  the objects they are observing.

app/observers/mailer_observer.rb

@@ -1,80 +0,0 @@
-class MailerObserver < ActiveRecord::Observer
-  observe :note, :merge_request
-  cattr_accessor :current_user
-
-  def after_create(model)
-    new_note(model) if model.kind_of?(Note)
-    new_merge_request(model) if model.kind_of?(MergeRequest)
-  end
-
-  def after_update(model)
-    changed_merge_request(model) if model.kind_of?(MergeRequest)
-  end
-
-  protected
-
-  def new_note(note)
-    if note.notify
-      # Notify whole team except author of note
-      notify_note(note)
-    elsif note.notify_author
-      # Notify only author of resource
-      Notify.note_commit_email(note.commit_author.id, note.id).deliver
-    else
-      # Otherwise ignore it
-      nil
-    end
-  end
-
-  def notify_note note
-    # reject author of note from mail list
-    users = note.project.users.reject { |u| u.id == current_user.id }
-
-    users.each do |u|
-      case note.noteable_type
-      when "Commit"; Notify.note_commit_email(u.id, note.id).deliver
-      when "Issue";  Notify.note_issue_email(u.id, note.id).deliver
-      when "Wiki";  Notify.note_wiki_email(u.id, note.id).deliver
-      when "MergeRequest"; Notify.note_merge_request_email(u.id, note.id).deliver
-      when "Snippet"; true
-      else
-        Notify.note_wall_email(u.id, note.id).deliver
-      end
-    end
-  end
-
-  def new_merge_request(merge_request)
-    if merge_request.assignee && merge_request.assignee != current_user
-      Notify.new_merge_request_email(merge_request.id).deliver
-    end
-  end
-
-  def changed_merge_request(merge_request)
-    status_notify_and_comment merge_request, :reassigned_merge_request_email
-  end
-
-  # This method used for Issues & Merge Requests
-  #
-  # It create a comment for Issue or MR if someone close/reopen.
-  # It also notify via email if assignee was changed 
-  #
-  def status_notify_and_comment target, mail_method
-    # If assigne changed - notify to recipients
-    if target.assignee_id_changed?
-      recipients_ids = target.assignee_id_was, target.assignee_id
-      recipients_ids.delete current_user.id
-
-      recipients_ids.each do |recipient_id|
-        Notify.send(mail_method, recipient_id, target.id, target.assignee_id_was).deliver
-      end
-    end
-
-    # Create comment about status changed
-    if target.closed_changed?
-      note = Note.new(noteable: target, project: target.project)
-      note.author = current_user
-      note.note = "_Status changed to #{target.closed ? 'closed' : 'reopened'}_"
-      note.save()
-    end
-  end
-end

app/observers/merge_request_observer.rb

@@ -0,0 +1,31 @@
+class MergeRequestObserver < ActiveRecord::Observer
+  cattr_accessor :current_user
+
+  def after_create(merge_request)
+    if merge_request.assignee && merge_request.assignee != current_user
+      Notify.new_merge_request_email(merge_request.id).deliver
+    end
+  end
+
+  def after_update(merge_request)
+    send_reassigned_email(merge_request) if merge_request.is_being_reassigned?
+
+    status = nil
+    status = 'closed' if merge_request.is_being_closed?
+    status = 'reopened' if merge_request.is_being_reopened?
+    if status
+      Note.create_status_change_note(merge_request, current_user, status)
+    end
+  end
+
+  protected
+
+  def send_reassigned_email(merge_request)
+      recipients_ids = merge_request.assignee_id_was, merge_request.assignee_id
+      recipients_ids.delete current_user.id
+
+      recipients_ids.each do |recipient_id|
+        Notify.reassigned_merge_request_email(recipient_id, merge_request.id, merge_request.assignee_id_was).deliver
+      end
+  end
+end

app/observers/note_observer.rb

@@ -0,0 +1,36 @@
+class NoteObserver < ActiveRecord::Observer
+
+  def after_create(note)
+    if note.notify
+      # Notify whole team except author of note
+      notify_team_of_new_note(note)
+    elsif note.notify_author
+      # Notify only author of resource
+      Notify.note_commit_email(note.commit_author.id, note.id).deliver
+    else
+      # Otherwise ignore it
+      nil
+    end
+  end
+
+  protected
+
+  def notify_team_of_new_note(note)
+    team_without_note_author(note).map do |u|
+      case note.noteable_type
+      when "Commit"; Notify.note_commit_email(u.id, note.id).deliver
+      when "Issue";  Notify.note_issue_email(u.id, note.id).deliver
+      when "Wiki";  Notify.note_wiki_email(u.id, note.id).deliver
+      when "MergeRequest"; Notify.note_merge_request_email(u.id, note.id).deliver
+      when "Wall"; Notify.note_wall_email(u.id, note.id).deliver
+      when "Snippet"; true # no notifications for snippets?
+      else
+        true
+      end
+    end
+  end
+
+  def team_without_note_author(note)
+    note.project.users.reject { |u| u.id == note.author.id }
+  end
+end