Narrow the type for the preg_replace_callback() callable.

Author: johnbillion

resources/functionMap.php

@@ -8833,7 +8833,7 @@
 'preg_match_all' => ['0|positive-int|false|null', 'pattern'=>'string', 'subject'=>'string', '&w_subpatterns='=>'array', 'flags='=>'int', 'offset='=>'int'],
 'preg_quote' => ['string', 'str'=>'string', 'delim_char='=>'string'],
 'preg_replace' => ['string|array|null', 'regex'=>'string|array', 'replace'=>'string|array', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
-'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
+'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_split' => ['array<int, string>|false', 'pattern'=>'string', 'subject'=>'string', 'limit='=>'?int', 'flags='=>'int'],
 'prev' => ['mixed', '&rw_array_arg'=>'array|object'],

resources/functionMap_php74delta.php

@@ -43,7 +43,7 @@
 'password_algos' => ['array<int, string>'],
 'password_hash' => ['string|false', 'password'=>'string', 'algo'=>'string|null', 'options='=>'array'],
 'password_needs_rehash' => ['bool', 'hash'=>'string', 'algo'=>'string|null', 'options='=>'array'],
-'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
+'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 'sapi_windows_set_ctrl_handler' => ['bool', 'callable'=>'callable(int):void', 'add='=>'bool'],
 'ReflectionProperty::getType' => ['?ReflectionType'],

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -630,6 +630,28 @@ public function testArrayWalkArrowFunctionCallback(): void
 ]);
 }
 
+public function testPregReplaceCallback(): void
+{
+$this->analyse([__DIR__ . '/data/preg_replace_callback.php'], [
+[
+'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(string): string given.',
+6,
+],
+[
+'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(string): string given.',
+13,
+],
+[
+'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(array): void given.',
+20,
+],
+[
+'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(): void given.',
+25,
+],
+]);
+}
+
 public function testUasortCallback(): void
 {
 $this->analyse([__DIR__ . '/data/uasort.php'], [

tests/PHPStan/Rules/Functions/data/preg_replace_callback.php

@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+// Incorrect
+$string = preg_replace_callback(
+'#pattern#',
+function(string $string): string {
+return $string;
+},
+'subject'
+);
+$string = preg_replace_callback(
+'#pattern#',
+function(string $string) {
+return $string;
+},
+'subject'
+);
+$string = preg_replace_callback(
+'#pattern#',
+function(array $matches) {},
+'subject'
+);
+$string = preg_replace_callback(
+'#pattern#',
+function() {},
+'subject'
+);
+
+// Correct
+$string = preg_replace_callback(
+'#pattern#',
+function(array $matches): string {
+return $matches[0];
+},
+'subject'
+);
+$string = preg_replace_callback(
+'#pattern#',
+function(array $matches) {
+return $matches[0];
+},
+'subject'
+);
+$string = preg_replace_callback(
+'#pattern#',
+function() {
+return 'Hello';
+},
+'subject'
+);