[12.x] fix no arguments return type in request class (#55631)

* fix `null` parameter return type in request class

* fix styling

Author: olivernybroe

src/Illuminate/Http/Request.php

@@ -417,7 +417,7 @@ public function get(string $key, mixed $default = null): mixed
      *
      * @param  string|null  $key
      * @param  mixed  $default
-     * @return \Symfony\Component\HttpFoundation\InputBag|mixed
+     * @return ($key is null ? \Symfony\Component\HttpFoundation\InputBag : mixed)
      */
     public function json($key = null, $default = null)
     {
@@ -633,7 +633,7 @@ public function user($guard = null)
      *
      * @param  string|null  $param
      * @param  mixed  $default
-     * @return \Illuminate\Routing\Route|object|string|null
+     * @return ($param is null ? \Illuminate\Routing\Route : object|string|null)
      */
     public function route($param = null, $default = null)
     {

types/Http/Request.php

@@ -14,3 +14,9 @@ enum TestEnum: string
 ]);
 
 assertType('TestEnum|null', $request->enum('key', TestEnum::class));
+
+assertType('Illuminate\Routing\Route', $request->route());
+assertType('object|string|null', $request->route('key'));
+
+assertType('Symfony\Component\HttpFoundation\InputBag', $request->json());
+assertType('mixed', $request->json('key'));