From 9442cef9f83d33f61aa9d7d066946637f74654e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ji=C5=99=C3=AD=20Pudil?= <me@jiripudil.cz>
Date: Fri, 20 Sep 2024 20:35:08 +0200
Subject: [PATCH] implement ClosureType::getReferencedTemplateTypes()

---
 src/Type/ClosureType.php                      | 20 +++++++++++++++++--
 .../MethodSignatureVarianceRuleTest.php       | 10 ++++++++++
 .../PHPStan/Rules/Generics/data/bug-10609.php | 16 +++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 tests/PHPStan/Rules/Generics/data/bug-10609.php

diff --git a/src/Type/ClosureType.php b/src/Type/ClosureType.php
index 6d987f6342..967b850525 100644
--- a/src/Type/ClosureType.php
+++ b/src/Type/ClosureType.php
@@ -36,10 +36,10 @@
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeHelper;
 use PHPStan\Type\Generic\TemplateTypeMap;
+use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\Generic\TemplateTypeVarianceMap;
 use PHPStan\Type\Traits\NonArrayTypeTrait;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
-use PHPStan\Type\Traits\NonGenericTypeTrait;
 use PHPStan\Type\Traits\NonIterableTypeTrait;
 use PHPStan\Type\Traits\NonOffsetAccessibleTypeTrait;
 use PHPStan\Type\Traits\NonRemoveableTypeTrait;
@@ -53,7 +53,6 @@ class ClosureType implements TypeWithClassName, CallableParametersAcceptor
 {
 
 	use NonArrayTypeTrait;
-	use NonGenericTypeTrait;
 	use NonIterableTypeTrait;
 	use UndecidedComparisonTypeTrait;
 	use NonOffsetAccessibleTypeTrait;
@@ -540,6 +539,23 @@ private function inferTemplateTypesOnParametersAcceptor(ParametersAcceptor $para
 		return $typeMap->union($this->getReturnType()->inferTemplateTypes($returnType));
 	}
 
+	public function getReferencedTemplateTypes(TemplateTypeVariance $positionVariance): array
+	{
+		$references = $this->getReturnType()->getReferencedTemplateTypes(
+			$positionVariance->compose(TemplateTypeVariance::createCovariant()),
+		);
+
+		$paramVariance = $positionVariance->compose(TemplateTypeVariance::createContravariant());
+
+		foreach ($this->getParameters() as $param) {
+			foreach ($param->getType()->getReferencedTemplateTypes($paramVariance) as $reference) {
+				$references[] = $reference;
+			}
+		}
+
+		return $references;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		if ($this->isCommonCallable) {
diff --git a/tests/PHPStan/Rules/Generics/MethodSignatureVarianceRuleTest.php b/tests/PHPStan/Rules/Generics/MethodSignatureVarianceRuleTest.php
index 8f743f4dc7..f01b15ba3d 100644
--- a/tests/PHPStan/Rules/Generics/MethodSignatureVarianceRuleTest.php
+++ b/tests/PHPStan/Rules/Generics/MethodSignatureVarianceRuleTest.php
@@ -234,4 +234,14 @@ public function testPr2465(): void
 		]);
 	}
 
+	public function testBug10609(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-10609.php'], [
+			[
+				'Template type A is declared as covariant, but occurs in contravariant position in parameter fn of method Bug10609\Collection::tap().',
+				13,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Generics/data/bug-10609.php b/tests/PHPStan/Rules/Generics/data/bug-10609.php
new file mode 100644
index 0000000000..c62a9e0a10
--- /dev/null
+++ b/tests/PHPStan/Rules/Generics/data/bug-10609.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Bug10609;
+
+/**
+ * @template-covariant A
+ */
+final class Collection
+{
+	/**
+	 * @param \Closure(A): A $fn
+	 */
+	public function tap(mixed $fn): void
+	{
+	}
+}