Attach behavior via "as behaviorName" with Closure

framework/base/Component.php

@@ -190,6 +190,8 @@
             $name = trim(substr($name, 3));
             if ($value instanceof Behavior) {
                 $this->attachBehavior($name, $value);
+            } elseif ($value instanceof \Closure) {
+                $this->attachBehavior($name, call_user_func($value));
             } elseif ((isset($value['class']) && is_subclass_of($value['class'], Behavior::class)) || (isset($value['__class']) && is_subclass_of($value['__class'], Behavior::class))) {
                 $this->attachBehavior($name, Yii::createObject($value));
             } elseif (is_string($value) && is_subclass_of($value, Behavior::class, true)) {

framework/db/BaseActiveRecord.php

@@ -1783,7 +1783,7 @@ private function isValueDifferent($newValue, $oldValue)
     {
         if (is_array($newValue) && is_array($oldValue)) {
             // Only sort associative arrays
-            $sorter = function(&$array) {
+            $sorter = function (&$array) {
                 if (ArrayHelper::isAssociative($array)) {
                     ksort($array);
                 }

framework/db/mssql/Schema.php

@@ -823,5 +823,4 @@ public function createColumnSchemaBuilder($type, $length = null)
     {
         return Yii::createObject(ColumnSchemaBuilder::className(), [$type, $length, $this->db]);
     }
-
 }

tests/framework/base/ComponentTest.php

@@ -328,22 +328,26 @@ public function testAttachBehavior()
         $this->assertTrue($component->hasProperty('p'));
         $component->test();
         $this->assertTrue($component->behaviorCalled);
+    }
 
-        $this->assertSame($behavior, $component->detachBehavior('a'));
-        $this->assertFalse($component->hasProperty('p'));
-        $this->expectException('yii\base\UnknownMethodException');
-        $component->test();
-
-        $p = 'as b';
+    public function testAs()
+    {
         $component = new NewComponent();
-        $component->$p = ['class' => 'NewBehavior'];
-        $this->assertSame($behavior, $component->getBehavior('a'));
+        $component->{'as a'} = new NewBehavior();
         $this->assertTrue($component->hasProperty('p'));
         $component->test();
         $this->assertTrue($component->behaviorCalled);
 
+        $component->{'as b'} = ['class' => NewBehavior::class];
+        $this->assertNotNull($component->getBehavior('b'));
+
         $component->{'as c'} = ['__class' => NewBehavior::class];
         $this->assertNotNull($component->getBehavior('c'));
+
+        $component->{'as d'} = function () {
+            return new NewBehavior();
+        };
+        $this->assertNotNull($component->getBehavior('d'));
     }
 
     public function testAttachBehaviors()
@@ -376,6 +380,9 @@ public function testDetachBehavior()
 
         $detachedBehavior = $component->detachBehavior('z');
         $this->assertNull($detachedBehavior);
+
+        $this->expectException('yii\base\UnknownMethodException');
+        $component->test();
     }
 
     public function testDetachBehaviors()