Regression test

Closes phpstan/phpstan#3118

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -479,4 +479,14 @@ public function testBug3120(): void
 		$this->analyse([__DIR__ . '/data/bug-3120.php'], []);
 	}
 
+	public function testBug3118(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-3118.php'], [
+			[
+				'Method Bug3118\CustomEnum2::all() should return Bug3118\EnumSet<static(Bug3118\CustomEnum2)> but returns Bug3118\CustomEnumSet.',
+				56,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-3118.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Bug3118;
+
+/**
+ * @template T of Enum
+ */
+class EnumSet
+{
+	private $type;
+
+	/**
+	 * @param class-string<T> $type
+	 */
+	public function __construct(string $type)
+	{
+		$this->type = $type;
+	}
+}
+
+abstract class Enum
+{
+	/**
+	 * @return EnumSet<static>
+	 */
+	public static function all(): EnumSet
+	{
+		return new EnumSet(static::class);
+	}
+}
+
+/**
+ * @extends EnumSet<CustomEnum>
+ */
+final class CustomEnumSet extends EnumSet
+{
+
+	public function __construct()
+	{
+		parent::__construct(CustomEnum::class);
+	}
+}
+
+final class CustomEnum extends Enum
+{
+	public static function all(): EnumSet
+	{
+		return new CustomEnumSet();
+	}
+}
+
+class CustomEnum2 extends Enum
+{
+	public static function all(): EnumSet
+	{
+		return new CustomEnumSet();
+	}
+}