bug #21937 [DependencyInjection] Handle void return types in closure-…

…proxy (pierredup)

This PR was squashed before being merged into the 3.3-dev branch (closes #21937).

Discussion
----------

[DependencyInjection] Handle void return types in closure-proxy

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | N/A
| License       | MIT
| Doc PR        | N/A

I recently got an error when registering an event listener that specifies a `void` return type. Dumping the container generates a closure proxy that always returns a value, which then conflicts with the return type hint.

E.G the following code is generated (some class names removed for readability)

```
$instance->addListener('kernel.view', /** @closure-proxy ... */ function (...\GetResponseForControllerResultEvent $event): void {
    return ${($_ = isset($this->services[listener']) ? $this->services['listener'] : $this->get('listener')) && false ?: '_'}->onKernelView($event);
}, 128);
```

This then causes the error `A void function must not return a value in ...`

So void return types should be handled by removing the `return` inside the closure

Commits
-------

a5c5ad1 [DependencyInjection] Handle void return types in closure-proxy

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -1656,7 +1656,9 @@ private function dumpValue($value, $interpolate = true)
             }
             $signature = preg_replace('/^(&?)[^(]*/', '$1', InheritanceProxyHelper::getSignature($r, $call));
 
-            return sprintf("/** @closure-proxy %s::%s */ function %s {\n            return %s->%s;\n        }", $class, $method, $signature, $this->dumpValue($reference), $call);
+            $return = 'void' !== InheritanceProxyHelper::getTypeHint($r);
+
+            return sprintf("/** @closure-proxy %s::%s */ function %s {\n            %s%s->%s;\n        }", $class, $method, $signature, $return ? 'return ' : '', $this->dumpValue($reference), $call);
         } elseif ($value instanceof Variable) {
             return '$'.$value;
         } elseif ($value instanceof Reference) {

src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php

@@ -614,6 +614,21 @@ public function testClosureProxy()
         $this->assertSame('reflection.Symfony\Component\DependencyInjection\Tests\Fixtures\Container31\Foo', (string) array_pop($res));
     }
 
+    /**
+     * @requires PHP 7.1
+     */
+    public function testClosureProxyWithVoidReturnType()
+    {
+        $container = include self::$fixturesPath.'/containers/container_dump_proxy_with_void_return_type.php';
+
+        $container->compile();
+        $dumper = new PhpDumper($container);
+
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/services_dump_proxy_with_void_return_type.php', $dumper->dump());
+        $res = $container->getResources();
+        $this->assertSame('reflection.Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid\Foo', (string) array_pop($res));
+    }
+
     /**
      * @requires PHP 7.1
      */

src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container_dump_proxy_with_void_return_type.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid;
+
+use Symfony\Component\DependencyInjection\Argument\ClosureProxyArgument;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+if (!class_exists(Foo::class, false)) {
+    class Foo
+    {
+        public function withVoid(): void
+        {
+        }
+    }
+}
+
+$container = new ContainerBuilder();
+
+$container->register('foo', Foo::class);
+
+$container->register('bar', 'stdClass')
+    ->setProperty('foo', array(
+        new ClosureProxyArgument('foo', 'withVoid'),
+    ))
+;
+
+return $container;

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services_dump_proxy_with_void_return_type.php

@@ -0,0 +1,91 @@
+<?php
+
+use Symfony\Component\DependencyInjection\Argument\RewindableGenerator;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\DependencyInjection\Container;
+use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
+use Symfony\Component\DependencyInjection\Exception\LogicException;
+use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ServiceLocator;
+
+/**
+ * ProjectServiceContainer.
+ *
+ * This class has been auto-generated
+ * by the Symfony Dependency Injection Component.
+ *
+ * @final since Symfony 3.3
+ */
+class ProjectServiceContainer extends Container
+{
+    private $parameters;
+    private $targetDirs = array();
+
+    /**
+     * Constructor.
+     */
+    public function __construct()
+    {
+        $this->services = array();
+        $this->normalizedIds = array(
+            'psr\\container\\containerinterface' => 'Psr\\Container\\ContainerInterface',
+            'symfony\\component\\dependencyinjection\\container' => 'Symfony\\Component\\DependencyInjection\\Container',
+            'symfony\\component\\dependencyinjection\\containerinterface' => 'Symfony\\Component\\DependencyInjection\\ContainerInterface',
+        );
+        $this->methodMap = array(
+            'bar' => 'getBarService',
+            'foo' => 'getFooService',
+        );
+
+        $this->aliases = array();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function compile()
+    {
+        throw new LogicException('You cannot compile a dumped frozen container.');
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
+    /**
+     * Gets the 'bar' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return \stdClass A stdClass instance
+     */
+    protected function getBarService()
+    {
+        $this->services['bar'] = $instance = new \stdClass();
+
+        $instance->foo = array(0 => /** @closure-proxy Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid\Foo::withVoid */ function (): void {
+            ${($_ = isset($this->services['foo']) ? $this->services['foo'] : $this->get('foo')) && false ?: '_'}->withVoid();
+        });
+
+        return $instance;
+    }
+
+    /**
+     * Gets the 'foo' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return \Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid\Foo A Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid\Foo instance
+     */
+    protected function getFooService()
+    {
+        return $this->services['foo'] = new \Symfony\Component\DependencyInjection\Tests\Fixtures\ContainerVoid\Foo();
+    }
+}