From ea2dddf410bc973cb4a2c80e5b6081be090b2757 Mon Sep 17 00:00:00 2001
From: Caleb White <cdwhite3@pm.me>
Date: Fri, 17 Jul 2026 16:23:40 -0500
Subject: [PATCH] fix: resolve static/self/parent relative to
 @param-closure-this bound class

When a closure or arrow function has its $this type overridden via
@param-closure-this, the static/self/parent keywords in return type
declarations were still resolving to the enclosing class instead of
the bound class.

Two fixes were needed:

1. Set inClosureBindScopeClasses when applying @param-closure-this so
   that resolveTypeByName and resolveName use the bound class for
   static/self resolution in expressions like static method calls.

2. Override the InitializerExprContext in getFunctionType when
   inClosureBindScopeClasses is set, so that static/self/parent in
   return type declarations (processed via ParserNodeTypeToPHPStanType)
   also resolve to the bound class instead of the enclosing class.
---
 src/Analyser/MutatingScope.php                | 44 ++++++++++++++++++-
 src/Analyser/NodeScopeResolver.php            |  6 ++-
 .../Analyser/nsrt/param-closure-this.php      | 28 ++++++++++++
 3 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 1f843048b25..b4da779f335 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -2020,7 +2020,7 @@ public function restoreThis(self $restoreThisScope): self
 			$expressionTypes,
 			$nativeExpressionTypes,
 			$this->conditionalExpressions,
-			$this->inClosureBindScopeClasses,
+			$restoreThisScope->inClosureBindScopeClasses,
 			$this->anonymousFunctionReflection,
 			$this->inFirstLevelStatement,
 			[],
@@ -2059,6 +2059,31 @@ public function isInClosureBind(): bool
 		return $this->inClosureBindScopeClasses !== [];
 	}
 
+	/**
+	 * @param list<non-empty-string> $scopeClasses
+	 */
+	public function withClosureBindScopeClasses(array $scopeClasses): self
+	{
+		return $this->scopeFactory->create(
+			$this->context,
+			$this->isDeclareStrictTypes(),
+			$this->getFunction(),
+			$this->getNamespace(),
+			$this->expressionTypes,
+			$this->nativeExpressionTypes,
+			$this->conditionalExpressions,
+			$scopeClasses,
+			$this->anonymousFunctionReflection,
+			$this->isInFirstLevelStatement(),
+			$this->currentlyAssignedExpressions,
+			$this->currentlyAllowedUndefinedExpressions,
+			$this->inFunctionCallsStack,
+			$this->afterExtractCall,
+			$this->parentScope,
+			$this->nativeTypesPromoted,
+		);
+	}
+
 	/**
 	 * @api
 	 * @param ParameterReflection[]|null $callableParameters
@@ -2397,6 +2422,23 @@ public function getFunctionType($type, bool $isNullable, bool $isVariadic): Type
 				false,
 			)), new AccessoryArrayListType()]);
 		}
+		if (
+			$type instanceof Name
+			&& $this->inClosureBindScopeClasses !== []
+			&& $this->inClosureBindScopeClasses !== ['static']
+			&& in_array($type->toLowerString(), ['static', 'self', 'parent'], true)
+			&& $this->reflectionProvider->hasClass($this->inClosureBindScopeClasses[0])
+		) {
+			return $this->initializerExprTypeResolver->getFunctionType(
+				$type,
+				$isNullable,
+				false,
+				InitializerExprContext::fromClassReflection(
+					$this->reflectionProvider->getClass($this->inClosureBindScopeClasses[0]),
+				),
+			);
+		}
+
 		return $this->initializerExprTypeResolver->getFunctionType($type, $isNullable, false, InitializerExprContext::fromScope($this));
 	}
 
diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index cb407c048ad..a4bbb443c6d 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -3656,7 +3656,8 @@ public function processArgs(
 					$closureThisType = $this->resolveClosureThisType($callLike, $calleeReflection, $parameter, $scopeToPass);
 					if ($closureThisType !== null) {
 						$restoreThisScope = $scopeToPass;
-						$scopeToPass = $scopeToPass->assignVariable('this', $closureThisType, new ObjectWithoutClassType(), TrinaryLogic::createYes());
+						$scopeToPass = $scopeToPass->assignVariable('this', $closureThisType, new ObjectWithoutClassType(), TrinaryLogic::createYes())
+							->withClosureBindScopeClasses($closureThisType->getObjectClassNames());
 					}
 				}
 
@@ -3722,7 +3723,8 @@ public function processArgs(
 				) {
 					$closureThisType = $this->resolveClosureThisType($callLike, $calleeReflection, $parameter, $scopeToPass);
 					if ($closureThisType !== null) {
-						$scopeToPass = $scopeToPass->assignVariable('this', $closureThisType, new ObjectWithoutClassType(), TrinaryLogic::createYes());
+						$scopeToPass = $scopeToPass->assignVariable('this', $closureThisType, new ObjectWithoutClassType(), TrinaryLogic::createYes())
+							->withClosureBindScopeClasses($closureThisType->getObjectClassNames());
 					}
 				}
 
diff --git a/tests/PHPStan/Analyser/nsrt/param-closure-this.php b/tests/PHPStan/Analyser/nsrt/param-closure-this.php
index 96f9fb8f159..ec32bbde8df 100644
--- a/tests/PHPStan/Analyser/nsrt/param-closure-this.php
+++ b/tests/PHPStan/Analyser/nsrt/param-closure-this.php
@@ -316,3 +316,31 @@ public function doFoo(): void
 	}
 
 }
+
+class StaticReturnClosureThis
+{
+
+	/**
+	 * @param-closure-this Foo $cb
+	 */
+	public function withFoo(callable $cb): void
+	{
+
+	}
+
+}
+
+class TestStaticResolutionInParamClosureThis
+{
+
+	public function test(StaticReturnClosureThis $o): void
+	{
+		$o->withFoo(function (): static {
+			assertType('ParamClosureThis\Foo', $this);
+			return $this;
+		});
+
+		$o->withFoo(fn (): static => $this);
+	}
+
+}