Extract observation of User to a UserObserver

app/models/mailer_observer.rb

 class MailerObserver < ActiveRecord::Observer
-  observe :issue, :user, :note, :merge_request
+  observe :issue, :note, :merge_request
   cattr_accessor :current_user
 
   def after_create(model)
-    new_user(model) if model.kind_of?(User)
     new_note(model) if model.kind_of?(Note)
     new_merge_request(model) if model.kind_of?(MergeRequest)
   end
@@ -14,10 +13,6 @@ class MailerObserver < ActiveRecord::Observer
 
   protected
 
-  def new_user(user)
-    Notify.new_user_email(user.id, user.password).deliver
-  end
-
   def new_note(note)
     if note.notify
       # Notify whole team except author of note

app/models/user_observer.rb

+class UserObserver < ActiveRecord::Observer
+  def after_create(user)
+    Notify.new_user_email(user.id, user.password).deliver
+  end
+end

config/application.rb

@@ -23,7 +23,7 @@ module Gitlab
     # config.plugins = [ :exception_notification, :ssl_requirement, :all ]
 
     # Activate observers that should always be running.
-    config.active_record.observers = :mailer_observer, :activity_observer, :project_observer, :key_observer, :issue_observer
+    config.active_record.observers = :mailer_observer, :activity_observer, :project_observer, :key_observer, :issue_observer, :user_observer
 
     # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
     # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.

spec/models/user_observer_spec.rb

+require 'spec_helper'
+
+describe UserObserver do
+  subject { UserObserver.instance }
+
+  it 'calls #after_create when new users are created' do
+    new_user = Factory.new(:user)
+    subject.should_receive(:after_create).with(new_user)
+
+    User.observers.enable :user_observer do
+      new_user.save
+    end
+  end
+
+  context 'when a new user is created' do
+    let(:user) { double(:user, id: 42, password: 'P@ssword!') }
+    let(:notification) { double :notification }
+
+    it 'sends an email' do
+      notification.should_receive(:deliver)
+      Notify.should_receive(:new_user_email).with(user.id, user.password).and_return(notification)
+
+      subject.after_create(user)
+    end
+  end
+end

spec/requests/admin/admin_users_spec.rb

@@ -40,14 +40,15 @@ describe "Admin::Users" do
     end
 
     it "should call send mail" do
-      User.observers.enable :mailer_observer do
-        Notify.should_receive(:new_user_email).and_return(stub(:deliver => true))
+      Notify.should_receive(:new_user_email).and_return(stub(:deliver => true))
+
+      User.observers.enable :user_observer do
         click_button "Save"
       end
     end
 
     it "should send valid email to user with email & password" do
-      User.observers.enable :mailer_observer do
+      User.observers.enable :user_observer do
         with_resque do
           click_button "Save"
         end