Add isset() tests for bug-14393

Add tests for isset($this->i) and isset($o->i) across all property
variants (initialized, uninitialized, PHPDoc-only, nullable, etc.)
as requested by reviewer.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -526,4 +526,28 @@ public function testBug9503(): void
 		$this->analyse([__DIR__ . '/data/bug-9503.php'], []);
 	}
 
+	public function testBug14393(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14393.php'], [
+			[
+				'Property Bug14393\MyClass::$i (int) in isset() is not nullable.',
+				12,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) in isset() is not nullable.',
+				35,
+			],
+			[
+				'Property Bug14393\MyClass::$i (int) in isset() is not nullable.',
+				75,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) in isset() is not nullable.',
+				85,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -396,15 +396,15 @@ public function testBug14393(): void
 			],
 			[
 				'Property Bug14393\MyClassPhpDoc::$i (int) on left side of ?? is not nullable.',
-				32,
+				34,
 			],
 			[
 				'Property Bug14393\MyClass::$i (int) on left side of ?? is not nullable.',
-				68,
+				74,
 			],
 			[
 				'Property Bug14393\MyClassPhpDoc::$i (int) on left side of ?? is not nullable.',
-				76,
+				84,
 			],
 		]);
 	}

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

@@ -9,6 +9,7 @@ class MyClass
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
@@ -19,6 +20,7 @@ class MyClassUninitialized
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
@@ -30,6 +32,7 @@ class MyClassPhpDoc
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
@@ -40,6 +43,7 @@ class MyClassNullable
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
@@ -50,6 +54,7 @@ class MyClassNullableWithDefault
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
@@ -60,29 +65,36 @@ class MyClassNullableWithNullDefault
 	public function doFoo(): void
 	{
 		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
 	}
 }
 
 $o = new MyClass();
 
 var_dump($o->i ?? -1);
+var_dump(isset($o->i));
 
 $o2 = new MyClassUninitialized();
 
 var_dump($o2->i ?? -1);
+var_dump(isset($o2->i));
 
 $o3 = new MyClassPhpDoc();
 
 var_dump($o3->i ?? -1);
+var_dump(isset($o3->i));
 
 $o4 = new MyClassNullable();
 
 var_dump($o4->i ?? -1);
+var_dump(isset($o4->i));
 
 $o5 = new MyClassNullableWithDefault();
 
 var_dump($o5->i ?? -1);
+var_dump(isset($o5->i));
 
 $o6 = new MyClassNullableWithNullDefault();
 
 var_dump($o6->i ?? -1);
+var_dump(isset($o6->i));