From d7097281ba7b8bbabf7ea3fe038f85db7c6fd266 Mon Sep 17 00:00:00 2001
From: Aleksandr Zhuravlev <aleks@macroactive.com>
Date: Wed, 31 Aug 2022 21:02:20 +1200
Subject: [PATCH] trim(), ltrim(), rtrim() now keep lowercase string attribute

---
 stubs/CoreGenericFunctions.phpstub | 14 +++++++++++++-
 tests/FunctionCallTest.php         | 27 +++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/stubs/CoreGenericFunctions.phpstub b/stubs/CoreGenericFunctions.phpstub
index 720ba46e1d8..6cc5eec57a4 100644
--- a/stubs/CoreGenericFunctions.phpstub
+++ b/stubs/CoreGenericFunctions.phpstub
@@ -566,6 +566,12 @@ function strpos($haystack, $needle, int $offset = 0) : int {}
 /**
  * @psalm-pure
  *
+ * @return (
+ *      $string is class-string
+ *          ? ($characters is '\\' ? class-string : string)
+ *          : ($string is lowercase-string ? lowercase-string : string)
+ * )
+ *
  * @psalm-flow ($string) -> return
  */
 function trim(string $string, string $characters = " \t\n\r\0\x0B") : string {}
@@ -573,7 +579,11 @@ function trim(string $string, string $characters = " \t\n\r\0\x0B") : string {}
 /**
  * @psalm-pure
  *
- * @return ($string is class-string ? ($characters is '\\' ? class-string : string) : string)
+ * @return (
+ *      $string is class-string
+ *          ? ($characters is '\\' ? class-string : string)
+ *          : ($string is lowercase-string ? lowercase-string : string)
+ * )
  *
  * @psalm-flow ($string) -> return
  */
@@ -582,6 +592,8 @@ function ltrim(string $string, string $characters = " \t\n\r\0\x0B") : string {}
 /**
  * @psalm-pure
  *
+ * @return ($string is lowercase-string ? lowercase-string : string)
+ *
  * @psalm-flow ($string) -> return
  */
 function rtrim(string $string, string $characters = " \t\n\r\0\x0B") : string {}
diff --git a/tests/FunctionCallTest.php b/tests/FunctionCallTest.php
index 955cc9b13e3..be4f4c32b17 100644
--- a/tests/FunctionCallTest.php
+++ b/tests/FunctionCallTest.php
@@ -1785,6 +1785,33 @@ function sayHello(string $needle): void {
                 [],
                 '8.0',
             ],
+            'trimSavesLowercaseAttribute' => [
+                '<?php
+                    $a = random_bytes(2);
+                    $b = trim(strtolower($a));
+                ',
+                'assertions' => [
+                    '$b===' => 'lowercase-string',
+                ],
+            ],
+            'ltrimSavesLowercaseAttribute' => [
+                '<?php
+                    $a = random_bytes(2);
+                    $b = ltrim(strtolower($a));
+                ',
+                'assertions' => [
+                    '$b===' => 'lowercase-string',
+                ],
+            ],
+            'rtrimSavesLowercaseAttribute' => [
+                '<?php
+                    $a = random_bytes(2);
+                    $b = rtrim(strtolower($a));
+                ',
+                'assertions' => [
+                    '$b===' => 'lowercase-string',
+                ],
+            ],
         ];
     }