From 0eed186edfff7fae4d5e3b6849b77efdb2308a9d Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Mon, 1 Feb 2021 21:40:30 -0500
Subject: [PATCH] Fix #5140 - always replace closure return types, whether or
 not a matching input type is present

---
 src/Psalm/Type/Atomic/CallableTrait.php     |  9 ++-
 tests/Template/ClassTemplateExtendsTest.php | 61 +++++++++++++--------
 2 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/src/Psalm/Type/Atomic/CallableTrait.php b/src/Psalm/Type/Atomic/CallableTrait.php
index 649b18c5b..ed579b063 100644
--- a/src/Psalm/Type/Atomic/CallableTrait.php
+++ b/src/Psalm/Type/Atomic/CallableTrait.php
@@ -222,16 +222,15 @@ trait CallableTrait
             }
         }
 
-        if (($input_type instanceof Atomic\TCallable || $input_type instanceof Atomic\TClosure)
-            && $callable->return_type
-            && $input_type->return_type
-        ) {
+        if ($callable->return_type) {
             $callable->return_type = TemplateStandinTypeReplacer::replace(
                 $callable->return_type,
                 $template_result,
                 $codebase,
                 $statements_analyzer,
-                $input_type->return_type,
+                $input_type instanceof Atomic\TCallable || $input_type instanceof Atomic\TClosure
+                    ? $input_type->return_type
+                    : null,
                 $input_arg_offset,
                 $calling_class,
                 $calling_function,
diff --git a/tests/Template/ClassTemplateExtendsTest.php b/tests/Template/ClassTemplateExtendsTest.php
index 1fa7d90fe..325289874 100644
--- a/tests/Template/ClassTemplateExtendsTest.php
+++ b/tests/Template/ClassTemplateExtendsTest.php
@@ -4282,29 +4282,6 @@ class ClassTemplateExtendsTest extends TestCase
                         function getIterator(): Traversable;
                     }'
             ],
-            'extendsWithoutAlias' => [
-                '<?php
-                    /**
-                     * @template TAValue
-                     */
-                    abstract class A {
-                        /**
-                         * @psalm-param TAValue $val
-                         */
-                        abstract public function foo($val): void;
-                    }
-
-                    /**
-                     * @template TBValue
-                     * @extends A<TBValue>
-                     */
-                    abstract class B extends A {
-                        /**
-                         * @psalm-param TBValue $val
-                         */
-                        abstract public function foo($val): void;
-                    }'
-            ],
             'extendsWithAlias' => [
                 '<?php
                     /**
@@ -4332,6 +4309,44 @@ class ClassTemplateExtendsTest extends TestCase
                         abstract public function foo($val): void;
                     }'
             ],
+            'extendsWithTemplatedClosureProperty' => [
+                '<?php
+                    /**
+                     * @template T1
+                     */
+                    class A
+                    {
+                        /**
+                         * @var T1|null
+                         */
+                        protected $type;
+
+                        /**
+                         * @var (Closure(): T1)|null
+                         */
+                        protected $closure;
+                    }
+
+                    /**
+                     * @template T2
+                     * @extends A<T2>
+                     */
+                    class B extends A {
+                        /**
+                         * @return T2|null
+                         */
+                        public function getType() {
+                            return $this->type;
+                        }
+
+                        /**
+                         * @return (Closure(): T2)|null
+                         */
+                        public function getClosureReturningType() {
+                            return $this->closure;
+                        }
+                    }'
+            ],
         ];
     }