implements session->push()

system/Session/Session.php

@@ -516,6 +516,24 @@ public function has(string $key)
 		return isset($_SESSION[$key]);
 	}
 
+       //--------------------------------------------------------------------
+
+      /**
+	 * Push new value onto session value that is array.
+	 *
+	 * @param string	   $key	Identifier of the session property we are interested in.
+       * @param array            $data   value to be pushed to existing session key.
+	 *
+	 * @return void
+	 */
+	public function push(string $key, array $data)
+	{
+               if ($this->has($key) && is_array($value = $this->get($key)))
+               {
+                   $this->set($key, array_merge($value, $data));
+               }
+	}
+
 	//--------------------------------------------------------------------
 
 	/**

tests/system/Session/SessionTest.php

@@ -170,6 +170,23 @@ public function testHasReturnsFalseOnNotFound()
         $this->assertFalse($session->has('bar'));
     }
 
+    public function testPushNewValueIntoArraySessionValue()
+    {
+        $session = $this->getInstance();
+        $session->start();
+
+        $session->set('hobbies', ['cooking' => 'baking']);
+        $session->push('hobbies', ['sport'=>'tennis']);
+
+        $this->assertEquals(
+            [
+                'cooking' => 'baking',
+                'sport'   => 'tennis',
+            ],
+            $session->get('hobbies')
+        );
+    }
+
     public function testRemoveActuallyRemoves()
     {
         $session = $this->getInstance();