Look for overriden property prototype in implemented interfaces

Author: ondrejmirtes

src/Rules/Properties/OverridingPropertyRule.php

@@ -213,19 +213,32 @@ private function findPrototype(ClassReflection $classReflection, string $propert
 	{
 		$parentClass = $classReflection->getParentClass();
 		if ($parentClass === null) {
-			return null;
+			return $this->findPrototypeInInterfaces($classReflection, $propertyName);
 		}
 
 		if (!$parentClass->hasNativeProperty($propertyName)) {
-			return null;
+			return $this->findPrototypeInInterfaces($classReflection, $propertyName);
 		}
 
 		$property = $parentClass->getNativeProperty($propertyName);
 		if ($property->isPrivate()) {
-			return null;
+			return $this->findPrototypeInInterfaces($classReflection, $propertyName);
 		}
 
 		return $property;
 	}
 
+	private function findPrototypeInInterfaces(ClassReflection $classReflection, string $propertyName): ?PhpPropertyReflection
+	{
+		foreach ($classReflection->getInterfaces() as $interface) {
+			if (!$interface->hasNativeProperty($propertyName)) {
+				continue;
+			}
+
+			return $interface->getNativeProperty($propertyName);
+		}
+
+		return null;
+	}
+
 }

tests/PHPStan/Rules/Properties/OverridingPropertyRuleTest.php

@@ -199,4 +199,19 @@ public function testFinal(): void
 		]);
 	}
 
+	public function testPropertyPrototypeFromInterface(): void
+	{
+		if (PHP_VERSION_ID < 80400) {
+			$this->markTestSkipped('Test requires PHP 8.4.');
+		}
+
+		$this->reportMaybes = true;
+		$this->analyse([__DIR__ . '/data/property-prototype-from-interface.php'], [
+			[
+				'Type string of property Bug12466\Bar::$a is not the same as type int of overridden property Bug12466\Foo::$a.',
+				15,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/property-prototype-from-interface.php

@@ -0,0 +1,17 @@
+<?php // lint >= 8.4
+
+namespace Bug12466;
+
+interface Foo
+{
+
+	public int $a { get; set;}
+
+}
+
+class Bar implements Foo
+{
+
+	public string $a;
+
+}