From ac79e9a3119eb7f35402a8e8ca09a12c51c3c5e3 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Thu, 31 Jan 2019 21:06:21 -0500
Subject: [PATCH] Fix #1263 - return proper class string

---
 src/Psalm/Type/Union.php  |  5 ++++-
 tests/ClassStringTest.php | 12 ++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Type/Union.php b/src/Psalm/Type/Union.php
index 8dbb13064..0e887334d 100644
--- a/src/Psalm/Type/Union.php
+++ b/src/Psalm/Type/Union.php
@@ -1059,7 +1059,10 @@ class Union
 
                         $new_types[$unknown_class_string->getKey()] = $unknown_class_string;
                     } elseif ($template_type_part instanceof Type\Atomic\TNamedObject) {
-                        $literal_class_string = new Type\Atomic\TClassString($template_type_part->value);
+                        $literal_class_string = new Type\Atomic\TClassString(
+                            $template_type_part->value,
+                            $template_type_part
+                        );
 
                         $new_types[$literal_class_string->getKey()] = $literal_class_string;
                     }
diff --git a/tests/ClassStringTest.php b/tests/ClassStringTest.php
index 41c2e15fe..9321b321c 100644
--- a/tests/ClassStringTest.php
+++ b/tests/ClassStringTest.php
@@ -485,6 +485,18 @@ class ClassStringTest extends TestCase
                         }
                     }'
             ],
+            'returnTemplatedClassString' => [
+                '<?php
+                    /**
+                     * @template T
+                     *
+                     * @param class-string<T> $shouldBe
+                     * @return class-string<T>
+                     */
+                    function identity(string $shouldBe) : string {  return $shouldBe; }
+
+                    identity(DateTimeImmutable::class)::createFromMutable(new DateTime());',
+            ],
         ];
     }