Fix non-final object cast to array

Author: VincentLanglet

src/Type/ObjectType.php

@@ -36,6 +36,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
 use PHPStan\Type\Accessory\AccessoryNumericStringType;
+use PHPStan\Type\Accessory\HasOffsetValueType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantStringType;
@@ -693,8 +694,17 @@ public function toArray(): Type
 			$classReflection = $classReflection->getParentClass();
 		} while ($classReflection !== null);
 
-		if (!$isFinal && count($arrayKeys) === 0) {
-			return new ArrayType(new MixedType(), new MixedType());
+		if (!$isFinal) {
+			if (count($arrayKeys) === 0 || count($arrayKeys) > 16) {
+				return new ArrayType(new MixedType(), new MixedType());
+			}
+
+			$types = [new ArrayType(new MixedType(), new MixedType())];
+			foreach ($arrayKeys as $i => $arrayKey) {
+				$types[] = new HasOffsetValueType($arrayKey, $arrayValues[$i]);
+			}
+
+			return new IntersectionType($types);
 		}
 
 		return new ConstantArrayType($arrayKeys, $arrayValues);

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php

@@ -1025,6 +1025,17 @@ public function testBug12412(): void
 		$this->analyse([__DIR__ . '/data/bug-12412.php'], []);
 	}
 
+	public function testBug2730(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-2730.php'], [
+			[
+				'Call to function is_object() with int will always evaluate to false.',
+				43,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.2')]
 	public function testBug13291(): void
 	{

tests/PHPStan/Rules/Comparison/data/bug-2730.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Bug2730;
+
+class A{
+	/** @var string */
+	public $a = "hi";
+	/** @var int */
+	public $b = 0;
+
+	public function dummy() : void{
+		foreach((array) $this as $k => $v){
+			if(is_string($v)){
+				echo "string\n";
+			}elseif(is_object($v)){
+				echo "object\n";
+			}else{
+				echo gettype($v) . "\n";
+			}
+		}
+	}
+}
+
+class B extends A{
+	/** @var \stdClass */
+	public $obj;
+
+	public function __construct(){
+		$this->obj = new \stdClass;
+	}
+}
+
+final class C{
+	/** @var string */
+	public $a = "hi";
+	/** @var int */
+	public $b = 0;
+
+	public function dummy() : void{
+		foreach((array) $this as $k => $v){
+			if(is_string($v)){
+				echo "string\n";
+			}elseif(is_object($v)){
+				echo "object\n";
+			}else{
+				echo gettype($v) . "\n";
+			}
+		}
+	}
+}