From 70f2fb7d1b0511cd87d9474f981cc0c24317020b Mon Sep 17 00:00:00 2001
From: Bruce Weirdan <weirdan@gmail.com>
Date: Mon, 23 Jan 2023 05:16:12 -0400
Subject: [PATCH] Check `$this` in static closures

Fixes vimeo/psalm#9148
Fixes vimeo/psalm#2813
---
 .../Internal/Analyzer/ClosureAnalyzer.php     |  2 +-
 .../Analyzer/FunctionLikeAnalyzer.php         |  4 ++-
 .../Reflector/FunctionLikeNodeScanner.php     |  2 ++
 src/Psalm/Storage/FunctionStorage.php         |  6 ++++
 tests/ClosureTest.php                         | 28 +++++++++++++++++++
 5 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/ClosureAnalyzer.php b/src/Psalm/Internal/Analyzer/ClosureAnalyzer.php
index 97930b24e..47b1af371 100644
--- a/src/Psalm/Internal/Analyzer/ClosureAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/ClosureAnalyzer.php
@@ -84,7 +84,7 @@ class ClosureAnalyzer extends FunctionLikeAnalyzer
 
         $codebase = $statements_analyzer->getCodebase();
 
-        if (!$statements_analyzer->isStatic()) {
+        if (!$statements_analyzer->isStatic() && !$closure_analyzer->isStatic()) {
             if ($context->collect_mutations &&
                 $context->self &&
                 $codebase->classExtends(
diff --git a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
index d86a5422d..77c4ff55f 100644
--- a/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/FunctionLikeAnalyzer.php
@@ -217,7 +217,9 @@ abstract class FunctionLikeAnalyzer extends SourceAnalyzer
             $this->suppressed_issues += $appearing_class_storage->suppressed_issues;
         }
 
-        if ($storage instanceof MethodStorage && $storage->is_static) {
+        if (($storage instanceof MethodStorage || $storage instanceof FunctionStorage)
+            && $storage->is_static
+        ) {
             $this->is_static = true;
         }
 
diff --git a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
index 494c888a0..ce008167b 100644
--- a/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
+++ b/src/Psalm/Internal/PhpVisitor/Reflector/FunctionLikeNodeScanner.php
@@ -1120,6 +1120,8 @@ class FunctionLikeNodeScanner
 
             $storage = $this->storage = $this->file_storage->functions[$function_id] = new FunctionStorage();
 
+            $storage->is_static = $stmt->static;
+
             if ($stmt instanceof PhpParser\Node\Expr\Closure) {
                 foreach ($stmt->uses as $closure_use) {
                     if ($closure_use->byRef && is_string($closure_use->var->name)) {
diff --git a/src/Psalm/Storage/FunctionStorage.php b/src/Psalm/Storage/FunctionStorage.php
index e39e7cc23..813730f56 100644
--- a/src/Psalm/Storage/FunctionStorage.php
+++ b/src/Psalm/Storage/FunctionStorage.php
@@ -6,4 +6,10 @@ final class FunctionStorage extends FunctionLikeStorage
 {
     /** @var array<string, bool> */
     public $byref_uses = [];
+
+    /**
+     * @var bool
+     * @todo lift this property to FunctionLikeStorage in Psalm 6
+     */
+    public $is_static = false;
 }
diff --git a/tests/ClosureTest.php b/tests/ClosureTest.php
index 6fff95861..34bac3dc5 100644
--- a/tests/ClosureTest.php
+++ b/tests/ClosureTest.php
@@ -1368,6 +1368,34 @@ class ClosureTest extends TestCase
                 'ignored_issues' => [],
                 'php_version' => '8.1',
             ],
+            'thisInStaticClosure' => [
+                'code' => '<?php
+                    class C {
+                        public string $a = "zzz";
+                        public function f(): void {
+                            $f = static function (): void {
+                                echo $this->a;
+                            };
+                            $f();
+                        }
+                    }
+                ',
+                'error_message' => 'InvalidScope',
+            ],
+            'thisInStaticArrowFunction' => [
+                'code' => '<?php
+                    class C {
+                        public int $a = 1;
+                        public function f(): int {
+                            $f = static fn(): int => $this->a;
+                            return $f();;
+                        }
+                    }
+                ',
+                'error_message' => 'InvalidScope',
+                'ignored_issues' => [],
+                'php_version' => '7.4',
+            ],
         ];
     }
 }