made optimizations

Author: rbessin

src/backend/src/utils/validation.utils.ts

@@ -211,15 +211,10 @@ export const materialValidators = [
 ];
 export const copyMaterialsValidators = [
   body('materialIds').isArray({ min: 1 }),
-  body('materialIds.*').isString().notEmpty(),
-  body('destinationWbsNum')
-    .custom((value) => {
-      validateWBS(value);
-      return true;
-    })
-    .customSanitizer((value) => {
-      return validateWBS(value);
-    })
+  nonEmptyString(body('materialIds.*')),
+  body('destinationWbsNum').customSanitizer((value) => {
+    return validateWBS(value);
+  })
 ];
 export const validateInputs = (req: Request, res: Response, next: Function): void => {
   const errors = validationResult(req);