MAGETWO-33063: Replace usage of __() to Phrase object in library

Author: Yuri Kovsher

dev/tests/static/testsuite/Magento/Test/Legacy/ObsoleteCodeTest.php

@@ -10,6 +10,8 @@
  */
 namespace Magento\Test\Legacy;
 
+use Magento\Framework\Test\Utility\Files;
+
 class ObsoleteCodeTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -129,6 +131,7 @@ function ($file) {
                 $this->_testObsoleteActions($content);
                 $this->_testObsoleteConstants($content);
                 $this->_testObsoletePropertySkipCalculate($content);
+                $this->checkLibraryDependence($content, $file);
             },
             \Magento\TestFramework\Utility\ChangedFiles::getPhpFiles(__DIR__ . '/_files/changed_files*')
         );
@@ -491,6 +494,25 @@ protected function _testObsoletePropertySkipCalculate($content)
         );
     }
 
+    /**
+     * Checks that library is not using app defined code
+     *
+     * @param string $content
+     * @param string $file
+     */
+    protected function checkLibraryDependence($content, $file)
+    {
+        $path = Files::init()->getPathToSource();
+        if (strpos($file, $path . '/lib/') === 0) {
+            $this->_assertNotRegexp(
+                '~(?<![a-z\\d_:]|->|function\\s)__\\s*\\(~iS',
+                $content,
+                'Function __() is defined outside of the library and must not be used there. ' .
+                'Replacement suggestion: new \\Magento\\Framework\\Phrase()'
+            );
+        }
+    }
+
     /**
      * Analyze contents to determine whether this is declaration of specified class/interface
      *

lib/internal/Magento/Framework/App/Response/Http/FileFactory.php

@@ -67,7 +67,7 @@ public function create(
                 $isFile = true;
                 $file = $content['value'];
                 if (!$dir->isFile($file)) {
-                    throw new \Exception(__('File not found'));
+                    throw new \Exception((string)new \Magento\Framework\Phrase('File not found'));
                 }
                 $contentLength = $dir->stat($file)['size'];
             }