Add a regex validation rule for the restrictRule setting

app/Api/v1/Requests/SettingUpdateRequest.php

@@ -3,6 +3,7 @@
 namespace App\Api\v1\Requests;
 
 use App\Rules\IsValidEmailList;
+use App\Rules\IsValidRegex;
 use Illuminate\Foundation\Http\FormRequest;
 use Illuminate\Support\Facades\Auth;
 
@@ -25,14 +26,28 @@ public function authorize()
      */
     public function rules()
     {
+        $routeParam = $this->route()?->parameter('settingName');
+
+        if ($routeParam == 'restrictList') {
+            $rule = [
+                'value' => [
+                    new IsValidEmailList,
+                ],
+            ];
+        }
+        else if ($routeParam == 'restrictRule') {
+            $rule = [
+                'value' => [
+                    new IsValidRegex,
+                ],
+            ];
+        }
+        else {
             $rule = [
                 'value' => [
                     'required',
                 ],
             ];
-
-        if ($this->route()?->parameter('settingName') == 'restrictList') {
-            $rule['value'][] = new IsValidEmailList;
         }
 
         return $rule;

app/Rules/IsValidRegex.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Rules;
+
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+
+class IsValidRegex implements ValidationRule
+{
+    /**
+     * Run the validation rule.
+     */
+    public function validate(string $attribute, mixed $value, Closure $fail) : void
+    {
+        try {
+            preg_match('/' . $value . '/', '');
+	
+            if (preg_last_error() !== PREG_NO_ERROR) {
+                $fail('validation.IsValidRegex')->translate();
+            }
+        }
+        catch (\Throwable $ex) {
+            $fail('validation.IsValidRegex')->translate();
+        }
+    }
+}

resources/lang/en/validation.php

@@ -143,6 +143,7 @@
 
     'single' => 'When using :attribute it must be the only parameter in this request body',
     'onlyCustomOtpWithUri' => 'The uri parameter must be provided alone or only in combination with the \'custom_otp\' parameter',
+    'IsValidRegex' => 'The :attribute must be a valid regex pattern.',
 
     /*
     |--------------------------------------------------------------------------
@@ -187,7 +188,7 @@
         ],
         'ids' => [
             'regex' => 'IDs must be comma separated, without trailing comma.',
-        ]
+        ],
     ],
 
     /*