Promoted constructor properties should not be doubled

tests/ProxyManagerTest/ProxyGenerator/ValueHolder/MethodGenerator/ConstructorTest.php

@@ -8,6 +8,7 @@
 use PHPUnit\Framework\TestCase;
 use ProxyManager\ProxyGenerator\ValueHolder\MethodGenerator\Constructor;
 use ProxyManagerTestAsset\ClassWithMixedProperties;
+use ProxyManagerTestAsset\ClassWithPromotedProperties;
 use ProxyManagerTestAsset\ClassWithVariadicConstructorArgument;
 use ProxyManagerTestAsset\EmptyClass;
 use ProxyManagerTestAsset\ProxyGenerator\LazyLoading\MethodGenerator\ClassWithTwoPublicProperties;
@@ -133,4 +134,25 @@ public function testBodyStructureWithVariadicArguments(): void
 
         self::assertSame($expectedCode, $constructor->getBody());
     }
+
+    public function testConstructorPropertyPromotion(): void
+    {
+        $valueHolder = $this->createMock(PropertyGenerator::class);
+
+        $valueHolder->method('getName')->willReturn('foo');
+
+        $constructor = Constructor::generateMethod(
+            new ReflectionClass(ClassWithPromotedProperties::class),
+            $valueHolder
+        );
+
+        self::assertSame('__construct', $constructor->getName());
+        $parameters = $constructor->getParameters();
+        self::assertCount(2, $parameters);
+
+        // Promoted constructor properties should not be doubled, since they are inherited anyway
+        $this->assertSame('int $amount', $parameters['amount']->generate());
+        $this->assertSame('?int $nullableAmount', $parameters['nullableAmount']->generate());
+    }
+
 }

tests/ProxyManagerTestAsset/ClassWithPromotedProperties.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ProxyManagerTestAsset;
+
+/**
+ * Class with a promoted constructor properties
+ *
+ * @license MIT
+ */
+class ClassWithPromotedProperties
+{
+    /**
+     * @param int $increment
+     */
+    public function __construct(
+        protected int $amount,
+        protected ?int $nullableAmount
+    ) {
+    }
+
+    public function getAmount(): int
+    {
+        return $this->amount;
+    }
+
+    public function getNullableAmount(): ?int
+    {
+        return $this->nullableAmount;
+    }
+}