[12.x] Prefer Symfony PHP polyfills over function_exists calls (#56621)

* Require Symfony PHP 8.3 polyfill in Support in favor of function existence check

* Require Symfony PHP 8.3 polyfill in Testing and Validation in favor of function existence check

Author: jnoordsij

src/Illuminate/Support/Str.php

@@ -4,7 +4,6 @@
 
 use Closure;
 use Illuminate\Support\Traits\Macroable;
-use JsonException;
 use League\CommonMark\Environment\Environment;
 use League\CommonMark\Extension\GithubFlavoredMarkdownExtension;
 use League\CommonMark\Extension\InlinesOnly\InlinesOnlyExtension;
@@ -577,17 +576,7 @@ public static function isJson($value)
             return false;
         }
 
-        if (function_exists('json_validate')) {
-            return json_validate($value, 512);
-        }
-
-        try {
-            json_decode($value, true, 512, JSON_THROW_ON_ERROR);
-        } catch (JsonException) {
-            return false;
-        }
-
-        return true;
+        return json_validate($value, 512);
     }
 
     /**
@@ -937,17 +926,7 @@ public static function numbers($value)
      */
     public static function padBoth($value, $length, $pad = ' ')
     {
-        if (function_exists('mb_str_pad')) {
-            return mb_str_pad($value, $length, $pad, STR_PAD_BOTH);
-        }
-
-        $short = max(0, $length - mb_strlen($value));
-        $shortLeft = floor($short / 2);
-        $shortRight = ceil($short / 2);
-
-        return mb_substr(str_repeat($pad, $shortLeft), 0, $shortLeft).
-               $value.
-               mb_substr(str_repeat($pad, $shortRight), 0, $shortRight);
+        return mb_str_pad($value, $length, $pad, STR_PAD_BOTH);
     }
 
     /**
@@ -960,13 +939,7 @@ public static function padBoth($value, $length, $pad = ' ')
      */
     public static function padLeft($value, $length, $pad = ' ')
     {
-        if (function_exists('mb_str_pad')) {
-            return mb_str_pad($value, $length, $pad, STR_PAD_LEFT);
-        }
-
-        $short = max(0, $length - mb_strlen($value));
-
-        return mb_substr(str_repeat($pad, $short), 0, $short).$value;
+        return mb_str_pad($value, $length, $pad, STR_PAD_LEFT);
     }
 
     /**
@@ -979,13 +952,7 @@ public static function padLeft($value, $length, $pad = ' ')
      */
     public static function padRight($value, $length, $pad = ' ')
     {
-        if (function_exists('mb_str_pad')) {
-            return mb_str_pad($value, $length, $pad, STR_PAD_RIGHT);
-        }
-
-        $short = max(0, $length - mb_strlen($value));
-
-        return $value.mb_substr(str_repeat($pad, $short), 0, $short);
+        return mb_str_pad($value, $length, $pad, STR_PAD_RIGHT);
     }
 
     /**

src/Illuminate/Support/composer.json

@@ -24,6 +24,7 @@
         "illuminate/contracts": "^12.0",
         "illuminate/macroable": "^12.0",
         "nesbot/carbon": "^3.8.4",
+        "symfony/polyfill-php83": "^1.31",
         "voku/portable-ascii": "^2.0.2"
     },
     "conflict": {

src/Illuminate/Testing/TestResponse.php

@@ -1757,11 +1757,9 @@ public function ddBody($key = null)
     {
         $content = $this->content();
 
-        if (function_exists('json_validate') && json_validate($content)) {
-            $this->ddJson($key);
-        }
-
-        dd($content);
+        return json_validate($content)
+            ? $this->ddJson($key)
+            : dd($content);
     }
 
     /**

src/Illuminate/Testing/composer.json

@@ -19,7 +19,8 @@
         "illuminate/collections": "^12.0",
         "illuminate/contracts": "^12.0",
         "illuminate/macroable": "^12.0",
-        "illuminate/support": "^12.0"
+        "illuminate/support": "^12.0",
+        "symfony/polyfill-php83": "^1.31"
     },
     "autoload": {
         "psr-4": {

src/Illuminate/Validation/Concerns/ValidatesAttributes.php

@@ -1631,13 +1631,7 @@ public function validateJson($attribute, $value)
             return false;
         }
 
-        if (function_exists('json_validate')) {
-            return json_validate($value);
-        }
-
-        json_decode($value);
-
-        return json_last_error() === JSON_ERROR_NONE;
+        return json_validate($value);
     }
 
     /**

src/Illuminate/Validation/composer.json

@@ -26,7 +26,8 @@
         "illuminate/support": "^12.0",
         "illuminate/translation": "^12.0",
         "symfony/http-foundation": "^7.2",
-        "symfony/mime": "^7.2"
+        "symfony/mime": "^7.2",
+        "symfony/polyfill-php83": "^1.31"
     },
     "autoload": {
         "psr-4": {