Regression test

Closes phpstan/phpstan#5589

Author: ondrejmirtes

tests/PHPStan/Rules/Methods/OverridingMethodRuleTest.php

@@ -510,4 +510,10 @@ public function testParameterTypeWidening(int $phpVersionId, array $errors): voi
 		$this->analyse([__DIR__ . '/data/parameter-type-widening.php'], $errors);
 	}
 
+	public function testBug5589(): void
+	{
+		$this->phpVersionId = PHP_VERSION_ID;
+		$this->analyse([__DIR__ . '/data/bug-5589.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-5589.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Bug5589;
+
+/**
+ * @template-covariant T of object
+ * @extends \ReflectionClass<T>
+ */
+class HelloWorld extends \ReflectionClass
+{
+	public static function export($argument, $return = false)
+	{
+		return '';
+	}
+}