From 8ccc19697afa69991b7c317beb922162a996ed81 Mon Sep 17 00:00:00 2001
From: Ivan Sidorov <nobxod@gmail.com>
Date: Wed, 27 Mar 2024 07:41:22 +0000
Subject: [PATCH] Part 6. Fix mixin collisions on properties

---
 .../Fetch/AtomicPropertyFetchAnalyzer.php     | 11 ++++
 tests/MixinsDeepTest.php                      | 50 +++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
index d483af45d05..466479de3bf 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/AtomicPropertyFetchAnalyzer.php
@@ -1258,6 +1258,9 @@ private static function handleNonExistentProperty(
         );
     }
 
+    /**
+     * @param string[] $ignore_mixins
+     */
     private static function handleRegularMixins(
         ClassLikeStorage $class_storage,
         TNamedObject $lhs_type_part,
@@ -1269,9 +1272,13 @@ private static function handleRegularMixins(
         PhpParser\Node\Expr\PropertyFetch $stmt,
         StatementsAnalyzer $statements_analyzer,
         string $fq_class_name,
+        array $ignore_mixins = [],
     ) {
         $property_exists = false;
         $naive_property_exists = false;
+
+        $ignore_mixins = [...$ignore_mixins, $fq_class_name];
+
         foreach ($class_storage->namedMixins as $mixin) {
             $new_property_id = $mixin->value . '::$' . $prop_name;
 
@@ -1314,6 +1321,9 @@ private static function handleRegularMixins(
                 }
                 $mixin_lhs_type_part = $mixin;
                 $mixin_fq_class_name = $mixin_class_storage->name;
+                if (in_array($mixin_fq_class_name, $ignore_mixins)) {
+                    continue;
+                }
                 [$new_lhs_type_part, $new_class_storage, $property_exists, $naive_property_exists, $new_property_id, $new_fq_class_name]
                     = self::handleRegularMixins(
                         $mixin_class_storage,
@@ -1326,6 +1336,7 @@ private static function handleRegularMixins(
                         $stmt,
                         $statements_analyzer,
                         $mixin_fq_class_name,
+                        $ignore_mixins,
                     );
                 if ($property_exists) {
                     $fq_class_name = $new_fq_class_name;
diff --git a/tests/MixinsDeepTest.php b/tests/MixinsDeepTest.php
index 98c48ddb50b..55961d10171 100644
--- a/tests/MixinsDeepTest.php
+++ b/tests/MixinsDeepTest.php
@@ -442,6 +442,56 @@ public static function __callStatic(string $name, array $arguments) {}
                 ],
                 'ignored_issues' => ['MixedAssignment'],
             ],
+            'LowMixinCollision_WithProperties' => [
+                'code' => <<<'PHP'
+                    <?php
+                    /**
+                     * @mixin Foo
+                     */
+                    class Foo {
+                        public function __get(string $name) {}
+                    }
+
+                    $foo = new Foo();
+                    $a = $foo->notExistsProp;
+                    PHP,
+                'assertions' => [
+                    '$a' => 'mixed',
+                ],
+                'ignored_issues' => ['MixedAssignment'],
+            ],
+            'DeepMixinCollision_WithProperties' => [
+                'code' => <<<'PHP'
+                    <?php
+                    /**
+                     * @mixin Baz
+                     */
+                    abstract class Foo {
+                        public function __get(string $name) {}
+                    }
+
+                    /**
+                     * @mixin Foo
+                     */
+                    abstract class Bar {
+                        public function __get(string $name) {}
+                    }
+
+                    /**
+                     * @mixin Bar
+                     */
+                    class Baz {
+                        public function __get(string $name) {}
+                    }
+
+                    $baz = new Baz();
+                    $a = $baz->notExistsProp;
+                    PHP,
+                'assertions' => [
+                    '$a' => 'mixed',
+                ],
+                'ignored_issues' => ['MixedAssignment'],
+            ],
         ];
     }
 }