symfony · fabpot · Feb 21, 2019 · Jun 9, 2018
diff --git a/src/Symfony/Component/PropertyInfo/CHANGELOG.md b/src/Symfony/Component/PropertyInfo/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+4.3.0
+-----
+
+* Added the ability to extract property type based on its initial value
+
 4.2.0
 -----
 

diff --git a/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php b/src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php
@@ -42,6 +42,12 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
      */
     public static $defaultArrayMutatorPrefixes = ['add', 'remove'];
 
+    private const MAP_TYPES = [
+        'integer' => Type::BUILTIN_TYPE_INT,
+        'boolean' => Type::BUILTIN_TYPE_BOOL,
+        'double' => Type::BUILTIN_TYPE_FLOAT,
+    ];
+
     private $mutatorPrefixes;
     private $accessorPrefixes;
     private $arrayMutatorPrefixes;
@@ -117,6 +123,10 @@ public function getTypes($class, $property, array $context = [])
         ) {
             return $fromConstructor;
         }
+
+        if ($fromDefaultValue = $this->extractFromDefaultValue($class, $property)) {
+            return $fromDefaultValue;
+        }
     }
 
     /**
@@ -258,6 +268,25 @@ private function extractFromConstructor(string $class, string $property): ?array
         return null;
     }
 
+    private function extractFromDefaultValue(string $class, string $property)
+    {
+        try {
+            $reflectionClass = new \ReflectionClass($class);
+        } catch (\ReflectionException $e) {
+            return null;
+        }
+
+        $defaultValue = $reflectionClass->getDefaultProperties()[$property] ?? null;
+
+        if (null === $defaultValue) {
+            return null;
+        }
+
+        $type = \gettype($defaultValue);
+
+        return [new Type(static::MAP_TYPES[$type] ?? $type)];
+    }
+
     private function extractFromReflectionType(\ReflectionType $reflectionType, \ReflectionMethod $reflectionMethod): Type
     {
         $phpTypeOrClass = $reflectionType->getName();

diff --git a/src/Symfony/Component/PropertyInfo/Tests/Extractor/ReflectionExtractorTest.php b/src/Symfony/Component/PropertyInfo/Tests/Extractor/ReflectionExtractorTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\PropertyInfo\Extractor\ReflectionExtractor;
 use Symfony\Component\PropertyInfo\Tests\Fixtures\AdderRemoverDummy;
+use Symfony\Component\PropertyInfo\Tests\Fixtures\DefaultValue;
 use Symfony\Component\PropertyInfo\Tests\Fixtures\NotInstantiable;
 use Symfony\Component\PropertyInfo\Tests\Fixtures\Php71Dummy;
 use Symfony\Component\PropertyInfo\Tests\Fixtures\Php71DummyExtended2;
@@ -208,6 +209,25 @@ public function php71TypesProvider()
         ];
     }
 
+    /**
+     * @dataProvider defaultValueProvider
+     */
+    public function testExtractWithDefaultValue($property, $type)
+    {
+        $this->assertEquals($type, $this->extractor->getTypes(DefaultValue::class, $property, []));
+    }
+
+    public function defaultValueProvider()
+    {
+        return [
+            ['defaultInt', [new Type(Type::BUILTIN_TYPE_INT, false)]],
+            ['defaultFloat', [new Type(Type::BUILTIN_TYPE_FLOAT, false)]],
+            ['defaultString', [new Type(Type::BUILTIN_TYPE_STRING, false)]],
+            ['defaultArray', [new Type(Type::BUILTIN_TYPE_ARRAY, false)]],
+            ['defaultNull', null],
+        ];
+    }
+
     /**
      * @dataProvider getReadableProperties
      */

diff --git a/src/Symfony/Component/PropertyInfo/Tests/Fixtures/DefaultValue.php b/src/Symfony/Component/PropertyInfo/Tests/Fixtures/DefaultValue.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Symfony\Component\PropertyInfo\Tests\Fixtures;
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\PropertyInfo\Tests\Fixtures;
+
+/**
+ * @author Tales Santos <[email protected]>
+ */
+class DefaultValue
+{
+    public $defaultInt = 30;
+    public $defaultFloat = 30.5;
+    public $defaultString = 'foo';
+    public $defaultArray = [];
+    public $defaultNull = null;
+}