From 8294602fe3f97df4191f2b8bf0f0b61b6fcab9b8 Mon Sep 17 00:00:00 2001
From: Michel Roca <mroca.dh@gmail.com>
Date: Tue, 22 Jul 2025 13:44:31 +0200
Subject: [PATCH] feat: infer preg_replace_callback return type

---
 ...afeFunctionsDynamicReturnTypeExtension.php |  9 +++++++-
 tests/Type/Php/data/preg_match_checked.php    |  4 ++--
 tests/Type/Php/data/preg_match_unchecked.php  |  4 ++--
 tests/Type/Php/data/preg_replace_return.php   | 23 +++++++++++++++++++
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php b/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
index 443d1bb..2b81b12 100644
--- a/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
+++ b/src/Type/Php/ReplaceSafeFunctionsDynamicReturnTypeExtension.php
@@ -16,12 +16,19 @@
 use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\TypeUtils;
 
+/**
+ * This file has been copy-pasted from PHPStan's source code but with isFunctionSupported changed.
+ * For now, only preg_* functions are supported.
+ * @See https://github.com/phpstan/phpstan-src/blob/2.1.x/src/Type/Php/ReplaceFunctionsDynamicReturnTypeExtension.php
+ */
 class ReplaceSafeFunctionsDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
 
-    /** @var array<string, int> */
+    /** @var array<string, int> The function name associated with the typed argument position used to type the return */
     private array $functions = [
         'Safe\preg_replace' => 2,
+        'Safe\preg_replace_callback' => 2,
+        'Safe\preg_replace_callback_array' => 1,
     ];
 
     public function isFunctionSupported(FunctionReflection $functionReflection): bool
diff --git a/tests/Type/Php/data/preg_match_checked.php b/tests/Type/Php/data/preg_match_checked.php
index 0ecea9f..0fbb3d9 100644
--- a/tests/Type/Php/data/preg_match_checked.php
+++ b/tests/Type/Php/data/preg_match_checked.php
@@ -12,9 +12,9 @@
 
 // @phpstan-ignore-next-line - use of unsafe is intentional
 if(\preg_match($pattern, $string, $matches)) {
-    \PHPStan\Testing\assertType($type, $matches);
+    \PHPStan\Testing\assertSuperType($type, $matches);
 }
 
 if(\Safe\preg_match($pattern, $string, $matches)) {
-    \PHPStan\Testing\assertType($type, $matches);
+    \PHPStan\Testing\assertSuperType($type, $matches);
 }
diff --git a/tests/Type/Php/data/preg_match_unchecked.php b/tests/Type/Php/data/preg_match_unchecked.php
index 8a55990..932cf5c 100644
--- a/tests/Type/Php/data/preg_match_unchecked.php
+++ b/tests/Type/Php/data/preg_match_unchecked.php
@@ -11,7 +11,7 @@
 
 // @phpstan-ignore-next-line - use of unsafe is intentional
 \preg_match($pattern, $string, $matches);
-\PHPStan\Testing\assertType($type, $matches);
+\PHPStan\Testing\assertSuperType($type, $matches);
 
 \Safe\preg_match($pattern, $string, $matches);
-\PHPStan\Testing\assertType($type, $matches);
+\PHPStan\Testing\assertSuperType($type, $matches);
diff --git a/tests/Type/Php/data/preg_replace_return.php b/tests/Type/Php/data/preg_replace_return.php
index 94d6c8c..c8eba5d 100644
--- a/tests/Type/Php/data/preg_replace_return.php
+++ b/tests/Type/Php/data/preg_replace_return.php
@@ -2,6 +2,8 @@
 
 namespace TheCodingMachine\Safe\PHPStan\Type\Php\data;
 
+// preg_replace
+
 // preg_replace with a string pattern should return a string
 $x = \Safe\preg_replace('/foo/', 'bar', 'baz');
 \PHPStan\Testing\assertType("string", $x);
@@ -9,3 +11,24 @@
 // preg_replace with an array pattern should return an array
 $x = \Safe\preg_replace(['/foo/'], ['bar'], ['baz']);
 \PHPStan\Testing\assertType("array", $x);
+
+// preg_replace_callback
+
+// preg_replace_callback with a string pattern should return a string
+$x = \Safe\preg_replace_callback('/foo/', fn (array $matches) => 'bar', 'baz');
+\PHPStan\Testing\assertType("string", $x);
+
+// preg_replace_callback with an array pattern should return an array
+$x = \Safe\preg_replace_callback(['/foo/'], fn (array $matches) => 'bar', ['baz']);
+\PHPStan\Testing\assertType("array", $x);
+
+
+// preg_replace_callback_array
+
+// preg_replace_callback_array with a string pattern should return a string
+$x = \Safe\preg_replace_callback_array(['/foo/' => fn (array $matches) => 'bar'], 'baz');
+\PHPStan\Testing\assertType("string", $x);
+
+// preg_replace_callback with an array pattern should return an array
+$x = \Safe\preg_replace_callback_array(['/foo/' => fn (array $matches) => 'bar'], ['baz']);
+\PHPStan\Testing\assertType("array", $x);