From 6f3039918942a5497f6187f71b116f1c068992cb Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Fri, 22 Jan 2021 09:58:09 -0500
Subject: [PATCH] =?UTF-8?q?Fix=20#5070=20=E2=80=93=20fix=20static=20return?=
 =?UTF-8?q?=20type=20inference=20in=20static=20methods?=
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---
 .../ExistingAtomicStaticCallAnalyzer.php      |  3 +-
 src/Psalm/Internal/Type/TypeExpander.php      |  2 ++
 tests/MethodSignatureTest.php                 | 34 +++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/StaticMethod/ExistingAtomicStaticCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/StaticMethod/ExistingAtomicStaticCallAnalyzer.php
index bfbbcc9fa..12c19526e 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/StaticMethod/ExistingAtomicStaticCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/StaticMethod/ExistingAtomicStaticCallAnalyzer.php
@@ -299,7 +299,8 @@ class ExistingAtomicStaticCallAnalyzer
                     true,
                     false,
                     \is_string($static_type)
-                        && $static_type !== $context->self
+                        && ($static_type !== $context->self
+                            || $class_storage->final)
                 );
 
                 $return_type_location = $codebase->methods->getMethodReturnTypeLocation(
diff --git a/src/Psalm/Internal/Type/TypeExpander.php b/src/Psalm/Internal/Type/TypeExpander.php
index 325c91a86..c5cc96ac0 100644
--- a/src/Psalm/Internal/Type/TypeExpander.php
+++ b/src/Psalm/Internal/Type/TypeExpander.php
@@ -165,6 +165,8 @@ class TypeExpander
                             $return_type->extra_types[$extra_static_type->getKey()] = clone $extra_static_type;
                         }
                     }
+                } elseif ($return_type->was_static && is_string($static_class_type) && $final) {
+                    $return_type->value = $static_class_type;
                 } elseif ($self_class && $return_type_lc === 'self') {
                     $return_type->value = $self_class;
                 } elseif ($parent_class && $return_type_lc === 'parent') {
diff --git a/tests/MethodSignatureTest.php b/tests/MethodSignatureTest.php
index 1e857e558..e87f384f6 100644
--- a/tests/MethodSignatureTest.php
+++ b/tests/MethodSignatureTest.php
@@ -869,6 +869,40 @@ class MethodSignatureTest extends TestCase
                 [],
                 '7.4'
             ],
+            'extendStaticReturnTypeInFinal' => [
+                '<?php
+                    final class B extends A
+                    {
+                        public static function doCretate1(): self
+                        {
+                            return self::create1();
+                        }
+
+                        public static function doCretate2(): self
+                        {
+                            return self::create2();
+                        }
+                    }
+
+                    abstract class A
+                    {
+                        final private function __construct() {}
+
+                        final protected static function create1(): static
+                        {
+                            return new static();
+                        }
+
+                        /** @return static */
+                        final protected static function create2()
+                        {
+                            return new static();
+                        }
+                    }',
+                [],
+                [],
+                '8.0'
+            ],
         ];
     }