api article factory fixed

modules/hudozka-api/src/factory/article.ts

@@ -2,8 +2,10 @@ import Article from '../core/Article'
 import { encodeImage } from './image'
 
 export function encodeArticle(article: Article) {
+    const preview = article.preview ? encodeImage(article.preview) : null
+
     return {
         ...article,
-        preview: encodeImage(article.preview),
+        preview,
     }
 }