Fix: cast nullable property

Author: yzen-dev

composer.json

@@ -1,6 +1,6 @@
 {
   "name": "yzen.dev/plain-to-class",
-  "version": "3.0.1",
+  "version": "3.0.2",
   "description": "Class-transformer to transform your dataset into a structured object",
   "minimum-stability": "dev",
   "prefer-stable": true,

composer.lock

@@ -14,10 +14,12 @@ class PropertyType
     /**
      * @param string $name Name of type
      * @param bool $isScalar
+     * @param bool $isNullable
      */
     public function __construct(
         public string $name,
-        public bool $isScalar
+        public bool $isScalar,
+        public bool $isNullable
     ) {
     }
 }

src/Reflection/Types/PropertyType.php

@@ -29,13 +29,16 @@ public static function create(RuntimeReflectionProperty $property)
 
         $type = TypeEnums::TYPE_MIXED;
         $isScalar = true;
+        $isNullable = true;
 
         if ($reflectionType instanceof ReflectionType) {
             $type = $reflectionType;
+            $isNullable = $reflectionType->allowsNull();
         }
         if ($reflectionType instanceof ReflectionNamedType) {
             $type = $reflectionType->getName();
             $isScalar = $reflectionType->isBuiltin();
+            $isNullable = $reflectionType->allowsNull();
         }
 
         if ($type === TypeEnums::TYPE_ARRAY) {
@@ -49,7 +52,8 @@ public static function create(RuntimeReflectionProperty $property)
             $arrayType ??= TypeEnums::TYPE_MIXED;
             $type = new ArrayType(
                 $type,
-                $isScalar
+                $isScalar,
+                $isNullable
             );
             $type->itemsType = $arrayType ?? TypeEnums::TYPE_MIXED;
             $type->isScalarItems = in_array($arrayType, [TypeEnums::TYPE_INTEGER, TypeEnums::TYPE_FLOAT, TypeEnums::TYPE_STRING, TypeEnums::TYPE_BOOLEAN, TypeEnums::TYPE_MIXED]);
@@ -60,20 +64,23 @@ public static function create(RuntimeReflectionProperty $property)
         if ($isScalar || $property->notTransform()) {
             return new ScalarType(
                 $type,
-                $isScalar
+                $isScalar,
+                $isNullable
             );
         }
 
         if (function_exists('enum_exists') && enum_exists($type)) {
             return new EnumType(
                 $type,
-                $isScalar
+                $isScalar,
+                $isNullable
             );
         }
 
         return new TransformableType(
             $type,
-            $isScalar
+            $isScalar,
+            $isNullable
         );
     }
 }

src/Reflection/Types/PropertyTypeFactory.php

@@ -47,6 +47,10 @@ public function __construct(ReflectionProperty $property, HydratorConfig $config
      */
     public function castAttribute(mixed $value): mixed
     {
+        if ($this->property->type->isNullable && empty($value)) {
+            return null;
+        }
+
         if (($this->property->type->isScalar && !$this->property->type instanceof ArrayType) || $this->property->notTransform()) {
             return $this->castScalar($this->property->type->name, $value);
         }

src/ValueCasting.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Units\DTO;
+
+use ClassTransformer\Attributes\WritingStyle;
+
+class TypesDto
+{
+    public ?int $nullableInt;
+
+    public ?string $nullableString;
+    public ?float $nullableFloat;
+    public ?bool $nullableBool;
+
+}

tests/Units/DTO/TypesDto.php

@@ -6,6 +6,7 @@
 use PHPUnit\Framework\TestCase;
 use Tests\Units\DTO\ExtendedDto;
 use ClassTransformer\Reflection\RuntimeReflectionProperty;
+use Tests\Units\DTO\TypesDto;
 
 class ValueCastingTest extends TestCase
 {
@@ -46,6 +47,23 @@ public function testCreateProperty(): void
         $value = $caster->castAttribute('1');
         $this->assertIsInt($value);
         $this->assertEquals(1, $value);
+        
+        
+        $caster = new ValueCasting(new RuntimeReflectionProperty(new \ReflectionProperty(TypesDto::class, 'nullableInt')));
+        $value = $caster->castAttribute('');
+        $this->assertNull($value);
+
+        $caster = new ValueCasting(new RuntimeReflectionProperty(new \ReflectionProperty(TypesDto::class, 'nullableString')));
+        $value = $caster->castAttribute('');
+        $this->assertNull($value);
+
+        $caster = new ValueCasting(new RuntimeReflectionProperty(new \ReflectionProperty(TypesDto::class, 'nullableFloat')));
+        $value = $caster->castAttribute('');
+        $this->assertNull($value);
+
+        $caster = new ValueCasting(new RuntimeReflectionProperty(new \ReflectionProperty(TypesDto::class, 'nullableBool')));
+        $value = $caster->castAttribute('');
+        $this->assertNull($value);
     }
 
     public function testCreateArrayProperty(): void