Add regression test for #12998

Closes phpstan/phpstan#12998

Author: phpstan-bot

tests/PHPStan/Rules/Comparison/MatchExpressionRuleTest.php

@@ -416,6 +416,17 @@ public function testBug13303(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.0')]
+	public function testBug12998(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-12998.php'], [
+			[
+				'Match expression does not handle remaining value: class-string<T of Bug12998\C|Bug12998\D>',
+				37,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.0')]
 	public function testBug9534(): void
 	{

tests/PHPStan/Rules/Comparison/data/bug-12998.php

@@ -0,0 +1,41 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug12998;
+
+final class A {}
+final class B {}
+
+class C {}
+class D {}
+
+/**
+ * Final classes with template: match IS exhaustive
+ *
+ * @template T of A|B
+ *
+ * @param class-string<T> $class
+ */
+function fooFinal(string $class): string
+{
+	return match ($class) {
+		A::class => 'a',
+		B::class => 'b',
+	};
+}
+
+/**
+ * Non-final classes with template: match can't be exhaustive
+ *
+ * @template T of C|D
+ *
+ * @param class-string<T> $class
+ */
+function fooNonFinal(string $class): string
+{
+	return match ($class) {
+		C::class => 'c',
+		D::class => 'd',
+	};
+}