Provide a polyfill for proxy-manager

composer.json

@@ -123,7 +123,8 @@
             "Symfony\\Component\\": "src/Symfony/Component/"
         },
         "classmap": [
-            "src/Symfony/Component/Intl/Resources/stubs"
+            "src/Symfony/Component/Intl/Resources/stubs",
+            "src/Symfony/Bridge/ProxyManager/Legacy/ProxiedMethodReturnExpression.php"
         ],
         "exclude-from-classmap": [
             "**/Tests/"

src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php

@@ -112,6 +112,10 @@ public function getProxyCode(Definition $definition)
             );
         }
 
+        if (version_compare(self::getProxyManagerVersion(), '2.5', '<')) {
+            $code = str_replace('\Closure::bind(function ', '\Closure::bind(static function ', $code);
+        }
+
         return $code;
     }
 

src/Symfony/Bridge/ProxyManager/Legacy/ProxiedMethodReturnExpression.php

@@ -0,0 +1,69 @@
+<?php
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace ProxyManager\Generator\Util;
+
+use Composer\Autoload\ClassLoader;
+use ReflectionMethod;
+use Symfony\Component\Debug\DebugClassLoader;
+
+if (class_exists(\ProxyManager\Version::class) && \version_compare(\ProxyManager\Version::getVersion(), '2.5', '<')) {
+    /**
+     * Utility class to generate return expressions in method, given a method signature.
+     *
+     * This is required since return expressions may be forbidden by the method signature (void).
+     *
+     * @author Marco Pivetta <ocramius@gmail.com>
+     * @license MIT
+     */
+    final class ProxiedMethodReturnExpression
+    {
+        public static function generate(string $returnedValueExpression, ?ReflectionMethod $originalMethod) : string
+        {
+            $originalReturnType = $originalMethod === null
+                ? null
+                : $originalMethod->getReturnType();
+            $originalReturnTypeName = $originalReturnType === null
+                ? null
+                : $originalReturnType->getName();
+            if ($originalReturnTypeName === 'void') {
+                return $returnedValueExpression . ";\nreturn;";
+            }
+            return 'return ' . $returnedValueExpression . ';';
+        }
+    }
+} else {
+    // Fallback to the original class by unregistering this file from composer class loader
+    $getComposerClassLoader = static function($functionLoader) use (&$getComposerClassLoader) {
+        if (\is_array($functionLoader)) {
+            $functionLoader = $functionLoader[0];
+        }
+        if (!\is_object($functionLoader)) {
+            return;
+        }
+        if ($functionLoader instanceof ClassLoader) {
+            return $functionLoader;
+        }
+        if ($functionLoader instanceof DebugClassLoader) {
+            return $getComposerClassLoader($functionLoader->getClassLoader());
+        }
+    };
+
+    $classLoader = null;
+    while($classLoader === null && count($functions = spl_autoload_functions()) > 0) {
+        $classLoader = $getComposerClassLoader(\array_shift($functions));
+    }
+
+    if (null === $classLoader) {
+        throw new \RuntimeException('Unable to find a class loader for "%s"');
+    }
+
+    $classLoader->addClassMap([ProxiedMethodReturnExpression::class => null]);
+    $classLoader->loadClass(ProxiedMethodReturnExpression::class);
+}

src/Symfony/Bridge/ProxyManager/Tests/LazyProxy/PhpDumper/ProxyDumperTest.php

@@ -63,6 +63,16 @@ public function testGetProxyCode()
         );
     }
 
+    public function testGetProxyMagicCode()
+    {
+        $definition = new Definition(__CLASS__);
+        $definition->setLazy(true);
+
+        $code = $this->dumper->getProxyCode($definition);
+
+        $this->assertStringContainsString('\Closure::bind(static function (\PHPUnit\Framework\TestCase $instance) {', $code);
+    }
+
     public function testDeterministicProxyCode()
     {
         $definition = new Definition(__CLASS__);

src/Symfony/Bridge/ProxyManager/composer.json

@@ -25,7 +25,7 @@
     },
     "autoload": {
         "psr-4": { "Symfony\\Bridge\\ProxyManager\\": "" },
-        "classmap": [ "Legacy/Debug.php" ],
+        "classmap": [ "Legacy/ProxiedMethodReturnExpression.php" ],
         "exclude-from-classmap": [
             "/Tests/"
         ]