From 89ab39f447465967f11808e4622c3c42ae91cca7 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Tue, 31 Mar 2026 00:20:07 +0000
Subject: [PATCH] Fix phpstan/phpstan#11776: Preserve narrowed template bounds
 during resolution

- When resolveTemplateTypes() replaces a template type with a standin
  of the same name and scope, preserve the narrower bound from PHPDoc
  intersections like (int|string)&TOperation
- New regression test in tests/PHPStan/Analyser/nsrt/bug-11776.php
- Root cause: ResolvedPropertyReflection called resolveTemplateTypes()
  which replaced TOperation of int|string with TOperation of scalar,
  losing the intersection narrowing from the PHPDoc type annotation
---
 src/Type/Generic/TemplateTypeHelper.php   | 16 ++++++++++++
 tests/PHPStan/Analyser/nsrt/bug-11776.php | 32 +++++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 tests/PHPStan/Analyser/nsrt/bug-11776.php

diff --git a/src/Type/Generic/TemplateTypeHelper.php b/src/Type/Generic/TemplateTypeHelper.php
index 6f09c29ccb2..5ea7cea18de 100644
--- a/src/Type/Generic/TemplateTypeHelper.php
+++ b/src/Type/Generic/TemplateTypeHelper.php
@@ -54,6 +54,22 @@ public static function resolveTemplateTypes(
 
 				$callSiteVariance = $callSiteVariances->getVariance($type->getName());
 				if ($callSiteVariance === null || $callSiteVariance->invariant()) {
+					if (
+						$newType instanceof TemplateType
+						&& $newType->getName() === $type->getName()
+						&& $newType->getScope()->equals($type->getScope())
+						&& !$type->getBound()->equals($newType->getBound())
+						&& $newType->getBound()->isSuperTypeOf($type->getBound())->yes()
+					) {
+						return TemplateTypeFactory::create(
+							$newType->getScope(),
+							$newType->getName(),
+							$type->getBound(),
+							$newType->getVariance(),
+							$newType->getStrategy(),
+							$newType->getDefault(),
+						);
+					}
 					return $newType;
 				}
 
diff --git a/tests/PHPStan/Analyser/nsrt/bug-11776.php b/tests/PHPStan/Analyser/nsrt/bug-11776.php
new file mode 100644
index 00000000000..94dff456258
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-11776.php
@@ -0,0 +1,32 @@
+<?php // lint >= 8.2
+
+declare(strict_types=1);
+
+namespace Bug11776;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @template TOperation of int|string
+ */
+interface EnumAsFilterInterface {}
+
+/**
+ * @template TOperation of scalar
+ */
+final readonly class ScalarableChoice
+{
+    /**
+     * @param class-string<EnumAsFilterInterface<(int|string)&TOperation>> $choiceClassName
+     */
+    public function __construct(private string $choiceClassName) {}
+
+    /**
+     * @return class-string<EnumAsFilterInterface<(int|string)&TOperation>>
+     */
+    public function getChoiceClassName(): string
+    {
+        assertType('class-string<Bug11776\EnumAsFilterInterface<TOperation of int|string (class Bug11776\ScalarableChoice, argument)>>', $this->choiceClassName);
+        return $this->choiceClassName;
+    }
+}