Constructor shoud use an interface, so that any class implementing the interface can be passed into this class.

Author: dverkade

lib/internal/Magento/Framework/ObjectManager/Definition/Compiled.php

@@ -18,15 +18,15 @@ abstract class Compiled implements \Magento\Framework\ObjectManager\DefinitionIn
     protected $_definitions;
 
     /**
-     * @var \Magento\Framework\Code\Reader\ClassReader
+     * @var \Magento\Framework\Code\Reader\ClassReaderInterface
      */
     protected $reader ;
 
     /**
      * @param array $definitions
-     * @param \Magento\Framework\Code\Reader\ClassReader $reader
+     * @param \Magento\Framework\Code\Reader\ClassReaderInterface $reader
      */
-    public function __construct(array $definitions, \Magento\Framework\Code\Reader\ClassReader $reader = null)
+    public function __construct(array $definitions, \Magento\Framework\Code\Reader\ClassReaderInterface $reader = null)
     {
         list($this->_signatures, $this->_definitions) = $definitions;
         $this->reader = $reader ?: new \Magento\Framework\Code\Reader\ClassReader();

lib/internal/Magento/Framework/ObjectManager/Definition/Runtime.php

@@ -15,9 +15,9 @@ class Runtime implements \Magento\Framework\ObjectManager\DefinitionInterface
     protected $_definitions = [];
 
     /**
-     * @param \Magento\Framework\Code\Reader\ClassReader $reader
+     * @param \Magento\Framework\Code\Reader\ClassReaderInterface $reader
      */
-    public function __construct(\Magento\Framework\Code\Reader\ClassReader $reader = null)
+    public function __construct(\Magento\Framework\Code\Reader\ClassReaderInterface $reader = null)
     {
         $this->_reader = $reader ?: new \Magento\Framework\Code\Reader\ClassReader();
     }

lib/internal/Magento/Framework/ObjectManager/Relations/Runtime.php

@@ -8,7 +8,7 @@
 class Runtime implements \Magento\Framework\ObjectManager\RelationsInterface
 {
     /**
-     * @var \Magento\Framework\Code\Reader\ClassReader
+     * @var \Magento\Framework\Code\Reader\ClassReaderInterface
      */
     protected $_classReader;
 
@@ -20,9 +20,9 @@ class Runtime implements \Magento\Framework\ObjectManager\RelationsInterface
     protected $_default = [];
 
     /**
-     * @param \Magento\Framework\Code\Reader\ClassReader $classReader
+     * @param \Magento\Framework\Code\Reader\ClassReaderInterface $classReader
      */
-    public function __construct(\Magento\Framework\Code\Reader\ClassReader $classReader = null)
+    public function __construct(\Magento\Framework\Code\Reader\ClassReaderInterface $classReader = null)
     {
         $this->_classReader = $classReader ?: new \Magento\Framework\Code\Reader\ClassReader();
     }