Fix false issue when passing enum case to generic class

src/Type/Generic/TemplateTypeVariance.php

@@ -7,6 +7,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\AcceptsResult;
 use PHPStan\Type\BenevolentUnionType;
+use PHPStan\Type\GeneralizePrecision;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
@@ -157,6 +158,12 @@ public function isValidVarianceWithReason(?TemplateType $templateType, Type $a,
 			return AcceptsResult::createYes();
 		}
 
+		if ($b->isEnum()->yes()) {
+			if ($b->generalize(GeneralizePrecision::lessSpecific())->equals($a)) {
+				return AcceptsResult::createYes();
+			}
+		}
+
 		if ($this->invariant()) {
 			$result = $a->equals($b);
 			$reasons = [];

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -2525,6 +2525,18 @@ public function testBug5869(): void
 		$this->analyse([__DIR__ . '/data/bug-5869.php'], []);
 	}
 
+	public function testBug10484(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$this->checkThisOnly = false;
+		$this->checkNullables = true;
+		$this->checkUnionTypes = true;
+		$this->analyse([__DIR__ . '/data/bug-10484.php'], []);
+	}
+
 	public function testGenericsEmptyArray(): void
 	{
 		$this->checkThisOnly = false;

tests/PHPStan/Rules/Methods/data/bug-10484.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Bug10484;
+
+enum Foo {
+	case Bar;
+}
+
+class Test {
+	/**
+	 * @param \Ds\Set<Foo> $foos
+	 */
+	public function bar(\Ds\Set $foos): void
+	{
+	}
+
+	public function test(): void
+	{
+		$this->bar(new \Ds\Set([Foo::Bar]));
+	}
+}