Fix phpstan/phpstan#13473: Take into account Property Hooks in __construct()

src/Analyser/MutatingScope.php

@@ -1574,7 +1574,7 @@ public function enterPropertyHook(
 
 		$realParameterTypes = $this->getRealParameterTypes($hook);
 
-		return $this->enterFunctionLike(
+		$scope = $this->enterFunctionLike(
 			new PhpMethodFromParserNodeReflection(
 				$this->getClassReflection(),
 				$hook,
@@ -1606,6 +1606,17 @@ public function enterPropertyHook(
 			),
 			true,
 		);
+
+		if ($hookName === 'set') {
+			foreach ($this->getClassReflection()->getNativeReflection()->getProperties() as $nativeProperty) {
+				if ($nativeProperty->hasDefaultValue()) {
+					continue;
+				}
+				$scope = $scope->invalidateExpression(new PropertyInitializationExpr($nativeProperty->getName()));
+			}
+		}
+
+		return $scope;
 	}
 
 	private function transformStaticType(Type $type): Type

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -526,6 +526,23 @@ public function testBug9503(): void
 		$this->analyse([__DIR__ . '/data/bug-9503.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.4')]
+	public function testBug13473(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-13473.php'], [
+			[
+				'Property Bug13473\Bar::$bar in isset() is not nullable nor uninitialized.',
+				30,
+			],
+			[
+				'Property Bug13473\Baz::$foo (int) in isset() is not nullable.',
+				67,
+			],
+		]);
+	}
+
 	public function testBug14393(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;

tests/PHPStan/Rules/Variables/data/bug-13473.php

@@ -0,0 +1,81 @@
+<?php // lint >= 8.4
+
+declare(strict_types = 1);
+
+namespace Bug13473;
+
+class Foo {
+    private(set) int $bar {
+        get => $this->bar;
+        set(int $bar) {
+            if (isset($this->bar)) {
+                throw new \Exception('bar is set');
+            }
+            $this->bar = $bar;
+        }
+    }
+
+    public function __construct(int $bar)
+    {
+        $this->bar = $bar;
+    }
+}
+
+$foo = new Foo(10);
+
+class Bar {
+    private(set) int $bar = 1 {
+        get => $this->bar;
+        set(int $bar) {
+            if (isset($this->bar)) {
+                throw new \Exception('bar is set');
+            }
+            $this->bar = $bar;
+        }
+    }
+
+    public function __construct(int $bar)
+    {
+        $this->bar = $bar;
+    }
+}
+
+class Qux {
+    private(set) int $foo;
+    private(set) int $bar {
+        get => $this->bar;
+        set(int $bar) {
+            if (isset($this->foo)) { // $foo has no default, could be uninitialized - no error
+                throw new \Exception('foo is set');
+            }
+            $this->bar = $bar;
+        }
+    }
+
+    public function __construct(int $bar)
+    {
+        $this->bar = $bar;
+        $this->foo = 42;
+    }
+}
+
+class Baz {
+    private(set) int $foo = 5;
+    private(set) int $bar {
+        get => $this->bar;
+        set(int $bar) {
+            if (isset($this->foo)) { // $foo has default value, always initialized - should error
+                echo 'foo is set';
+            }
+            if (isset($this->bar)) { // $bar has no default, could be uninitialized - no error
+                throw new \Exception('bar is set');
+            }
+            $this->bar = $bar;
+        }
+    }
+
+    public function __construct(int $bar)
+    {
+        $this->bar = $bar;
+    }
+}