some explanations

Observer/User.php

@@ -5,7 +5,7 @@ namespace DesignPatterns\Observer;
 /**
  * Observer pattern : The observed object (the subject)
  * 
- * The subject maintains a list of Observer and send notificiations.
+ * The subject maintains a list of Observers and sends notifications.
  *
  */
 class User implements \SplSubject

Observer/UserObserver.php

@@ -18,6 +18,12 @@ namespace DesignPatterns\Observer;
 class UserObserver implements \SplObserver
 {
 
+    /**
+     * This is the only method to implement as an observer.
+     * It is called by the Subject (usually by SplSubject::notify() )
+     * 
+     * @param \SplSubject $subject
+     */
     public function update(\SplSubject $subject)
     {
         echo get_class($subject) . ' has been updated';

Tests/Observer/ObserverTest.php

@@ -18,6 +18,9 @@ class ObserverTest extends \PHPUnit_Framework_TestCase
         $this->observer = new UserObserver();
     }
 
+    /**
+     * Tests the notification
+     */
     public function testNotify()
     {
         $this->expectOutputString('DesignPatterns\Observer\User has been updated');
@@ -27,6 +30,9 @@ class ObserverTest extends \PHPUnit_Framework_TestCase
         $subject->property = 123;
     }
 
+    /**
+     * Tests the subscribing
+     */
     public function testAttachDetach()
     {
         $subject = new User();
@@ -37,6 +43,9 @@ class ObserverTest extends \PHPUnit_Framework_TestCase
         $this->assertAttributeEmpty('_observers', $subject);
     }
 
+    /**
+     * Tests the update() invocation on a mockup
+     */
     public function testUpdateCalling()
     {
         $subject = new User();