feature #34769 [DependencyInjection] Autowire public typed properties (Plopix)

This PR was merged into the 5.1-dev branch.

Discussion
----------

[DependencyInjection] Autowire public typed properties

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| License       | MIT

### Description

This PR adds the Autowiring of **public typed properties** in PHP 7.4.
It is only on "public" properties.

It could let people think that services are better injected in "public".
I don't know what to think about it, you?

### How about "private" properties - further thinking

Even if I think that it would be awesome to be able to inject in "private" properties, we discussed it with @nicolas-grekas, and I agree Symfony should not break any standard logic. If the property is private then it is private the DI cannot touch it.

But that could/would remove a lot of boilerplate, and if it is declarative, that might still be something to do.
Maybe we could introduce a new annotation for injection in "private": `@requiredPrivated` ?

Commits
-------

cad7fbb9f7 [DI] Autowire public typed properties

src/Symfony/Component/DependencyInjection/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+5.1.0
+-----
+
+ * added support to autowire public typed properties in php 7.4
+
 5.0.0
 -----
 

src/Symfony/Component/DependencyInjection/Compiler/AutowireRequiredPropertiesPass.php

@@ -0,0 +1,61 @@
+<?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 Symfony\Component\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\DependencyInjection\TypedReference;
+
+/**
+ * Looks for definitions with autowiring enabled and registers their corresponding "@required" properties.
+ *
+ * @author Sebastien Morel (Plopix) <morel.seb@gmail.com>
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class AutowireRequiredPropertiesPass extends AbstractRecursivePass
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected function processValue($value, bool $isRoot = false)
+    {
+        if (\PHP_VERSION_ID < 70400) {
+            return $value;
+        }
+        $value = parent::processValue($value, $isRoot);
+
+        if (!$value instanceof Definition || !$value->isAutowired() || $value->isAbstract() || !$value->getClass()) {
+            return $value;
+        }
+        if (!$reflectionClass = $this->container->getReflectionClass($value->getClass(), false)) {
+            return $value;
+        }
+
+        $properties = $value->getProperties();
+        foreach ($reflectionClass->getProperties() as $reflectionProperty) {
+            if (false === $doc = $reflectionProperty->getDocComment()) {
+                continue;
+            }
+            if (false === stripos($doc, '@required') || !preg_match('#(?:^/\*\*|\n\s*+\*)\s*+@required(?:\s|\*/$)#i', $doc)) {
+                continue;
+            }
+            if (\array_key_exists($name = $reflectionProperty->getName(), $properties)) {
+                continue;
+            }
+
+            $type = $reflectionProperty->getType()->getName();
+            $value->setProperty($name, new TypedReference($type, $type, ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, $name));
+        }
+
+        return $value;
+    }
+}

src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php

@@ -57,6 +57,7 @@ class PassConfig
             new ResolveFactoryClassPass(),
             new ResolveNamedArgumentsPass(),
             new AutowireRequiredMethodsPass(),
+            new AutowireRequiredPropertiesPass(),
             new ResolveBindingsPass(),
             new ServiceLocatorTagPass(),
             new CheckDefinitionValidityPass(),

src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowireRequiredPropertiesPassTest.php

@@ -0,0 +1,46 @@
+<?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 Symfony\Component\DependencyInjection\Tests\Compiler;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Compiler\AutowireRequiredPropertiesPass;
+use Symfony\Component\DependencyInjection\Compiler\ResolveClassPass;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+require_once __DIR__.'/../Fixtures/includes/autowiring_classes.php';
+
+if (\PHP_VERSION_ID >= 70400) {
+    require_once __DIR__.'/../Fixtures/includes/autowiring_classes_74.php';
+}
+
+/**
+ * @requires PHP 7.4
+ */
+class AutowireRequiredPropertiesPassTest extends TestCase
+{
+    public function testInjection()
+    {
+        $container = new ContainerBuilder();
+        $container->register(Bar::class);
+        $container->register(A::class);
+        $container->register(B::class);
+        $container->register(PropertiesInjection::class)->setAutowired(true);
+
+        (new ResolveClassPass())->process($container);
+        (new AutowireRequiredPropertiesPass())->process($container);
+
+        $properties = $container->getDefinition(PropertiesInjection::class)->getProperties();
+
+        $this->assertArrayHasKey('plop', $properties);
+        $this->assertEquals(Bar::class, (string) $properties['plop']);
+    }
+}

src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/autowiring_classes_74.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Compiler;
+
+class PropertiesInjection
+{
+    /**
+     * @required
+     */
+    public Bar $plop;
+
+    public function __construct(A $a)
+    {
+    }
+}