Fix phpstan/phpstan#14393: Warn about ?? on non-nullable native-typed instance properties

- Removed bail-out in IssetCheck for native-typed instance properties accessed on non-$this objects
- Static properties still bail out (valid lazy initialization pattern with ??=)
- $this->prop still respects initialization tracking as before
- Updated NullCoalesceRuleTest to always expect warning for ReflectionClass::$name
- Updated IssetRuleTest to expect warnings for all native-typed instance properties
- Removed unnecessary ?? null in ArrayFindFunctionReturnTypeExtension
- New regression test in tests/PHPStan/Rules/Variables/data/bug-14393.php

Author: VincentLanglet

src/Rules/IssetCheck.php

@@ -182,15 +182,21 @@ static function (Type $type) use ($typeMessageCallback): ?string {
 				}
 
 				if (!$scope->hasExpressionType($expr)->yes()) {
-					if ($expr instanceof Node\Expr\PropertyFetch) {
+					if (
+						$expr instanceof Node\Expr\PropertyFetch
+						&& $expr->var instanceof Expr\Variable
+						&& $expr->var->name === 'this'
+					) {
 						return $this->checkUndefined($expr->var, $scope, $operatorDescription, $identifier);
 					}
 
-					if ($expr->class instanceof Expr) {
-						return $this->checkUndefined($expr->class, $scope, $operatorDescription, $identifier);
-					}
+					if ($expr instanceof Node\Expr\StaticPropertyFetch) {
+						if ($expr->class instanceof Expr) {
+							return $this->checkUndefined($expr->class, $scope, $operatorDescription, $identifier);
+						}
 
-					return null;
+						return null;
+					}
 				}
 			}
 

src/Type/Php/ArrayFindFunctionReturnTypeExtension.php

@@ -37,8 +37,8 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			return null;
 		}
 
-		$arrayArg = $args[0]->value ?? null;
-		$callbackArg = $args[1]->value ?? null;
+		$arrayArg = $args[0]->value;
+		$callbackArg = $args[1]->value;
 
 		$resultTypes = $this->arrayFilterFunctionReturnTypeHelper->getType($scope, $arrayArg, $callbackArg, null);
 		$resultType = TypeCombinator::union(...array_map(static fn ($type) => $type->getIterableValueType(), $resultTypes->getArrays()));

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -202,17 +202,18 @@ public function testNativePropertyTypes(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;
 		$this->analyse([__DIR__ . '/data/isset-native-property-types.php'], [
-			/*[
-				// no way to achieve this with current PHP Reflection API
-				// There's ReflectionClass::getDefaultProperties()
-				// but it cannot differentiate between `public int $foo` and `public int $foo = null`;
+			[
 				'Property IssetNativePropertyTypes\Foo::$hasDefaultValue (int) in isset() is not nullable.',
 				17,
-			],*/
+			],
 			[
 				'Property IssetNativePropertyTypes\Foo::$isAssignedBefore (int) in isset() is not nullable.',
 				20,
 			],
+			[
+				'Property IssetNativePropertyTypes\Foo::$canBeUninitialized (int) in isset() is not nullable.',
+				22,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -8,7 +8,6 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
 use PHPUnit\Framework\Attributes\RequiresPhp;
-use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<NullCoalesceRule>
@@ -114,12 +113,10 @@ public function testCoalesceRule(): void
 				131,
 			],
 		];
-		if (PHP_VERSION_ID < 80100) {
-			$errors[] = [
-				'Property ReflectionClass<object>::$name (class-string<object>) on left side of ?? is not nullable.',
-				136,
-			];
-		}
+		$errors[] = [
+			'Property ReflectionClass<object>::$name (class-string<object>) on left side of ?? is not nullable.',
+			136,
+		];
 		$errors[] = [
 			'Variable $foo on left side of ?? is never defined.',
 			141,
@@ -377,4 +374,14 @@ public function testBug13921(): void
 		]);
 	}
 
+	public function testBug14393(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14393.php'], [
+			[
+				'Property Bug14393\MyClass::$i (int) on left side of ?? is not nullable.',
+				12,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-14393.php

@@ -0,0 +1,12 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14393;
+
+class MyClass
+{
+	public int $i = 10;
+}
+
+$o = new MyClass();
+
+var_dump($o->i ?? -1);