fix: make form submit apply modification on existing article

app/Http/Requests/Admin/Shop/StoreArticlePost.php

@@ -3,6 +3,7 @@
 namespace App\Http\Requests\Admin\Shop;
 
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
 
 class StoreArticlePost extends FormRequest
 {
@@ -13,8 +14,13 @@ class StoreArticlePost extends FormRequest
 
     public function rules()
     {
+        $articleId = $this->input('id');
+
         return [
-            'ref' => 'required|unique:shop_articles',
+            'ref' => [
+                'required',
+                Rule::unique('shop_articles', 'ref')->ignore($articleId)->whereNull('deleted_at'),
+            ],
             'product_type' => 'required',
             'product_id' => 'required',
             'article_nature_id' => 'required',