From c1e008e4f6c3b199b34b08eed41e8151f442970d Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Mon, 10 Jan 2022 12:35:45 +0100
Subject: [PATCH] PHP 8.1: Report missing typehints in overridden native
 methods

---
 .../Internal/Analyzer/MethodComparator.php    | 28 +++++++++++++++++++
 .../Type/Comparator/UnionTypeComparator.php   |  2 +-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/MethodComparator.php b/src/Psalm/Internal/Analyzer/MethodComparator.php
index 0de16d9ef99..da8fdf02f39 100644
--- a/src/Psalm/Internal/Analyzer/MethodComparator.php
+++ b/src/Psalm/Internal/Analyzer/MethodComparator.php
@@ -116,6 +116,20 @@ public static function compare(
             );
         }
 
+        if (!$guide_classlike_storage->user_defined
+            && $implementer_classlike_storage->user_defined
+            && $codebase->analysis_php_version_id >= 8_01_00
+            && !$implementer_method_storage->signature_return_type
+        ) {
+            IssueBuffer::maybeAdd(
+                new MethodSignatureMismatch(
+                    'Method ' . $cased_implementer_method_id . ' is missing a return type signature!',
+                    $implementer_method_storage->location
+                ),
+                $suppressed_issues + $implementer_classlike_storage->suppressed_issues
+            );
+        }
+
         if ($guide_method_storage->return_type
             && $implementer_method_storage->return_type
             && !$implementer_method_storage->inherited_return_type
@@ -519,6 +533,20 @@ private static function compareMethodParams(
                 $suppressed_issues + $implementer_classlike_storage->suppressed_issues
             );
         }
+
+        if (!$guide_classlike_storage->user_defined
+            && $implementer_classlike_storage->user_defined
+            && $codebase->analysis_php_version_id >= 8_01_00
+            && !$implementer_param->signature_type
+        ) {
+            IssueBuffer::maybeAdd(
+                new MethodSignatureMismatch(
+                    'Argument ' . ($i + 1) . ' of ' . $cased_implementer_method_id . ' is missing a type signature!',
+                    $implementer_param->location
+                ),
+                $suppressed_issues + $implementer_classlike_storage->suppressed_issues
+            );
+        }
     }
 
     /**
diff --git a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
index 288f3e25845..25a1d503583 100644
--- a/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php
@@ -303,7 +303,7 @@ public static function isContainedByInPhp(
         Union $container_type
     ): bool {
         if ($container_type->isMixed()) {
-            return true;
+            return !!$input_type;
         }
 
         if (!$input_type) {