From 72da365249419a438a474766afb189499b17cfaa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20My=C5=9Bliwiec?= <mail@kamilmysliwiec.com>
Date: Tue, 1 Aug 2023 11:05:01 +0200
Subject: [PATCH] fix: check if keys with validation constraints exist

---
 lib/type-helpers/partial-type.helper.ts | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/type-helpers/partial-type.helper.ts b/lib/type-helpers/partial-type.helper.ts
index d7bbaff6c..1872b8ad1 100644
--- a/lib/type-helpers/partial-type.helper.ts
+++ b/lib/type-helpers/partial-type.helper.ts
@@ -27,9 +27,11 @@ export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
     classRef,
     PartialTypeClass
   );
-  keysWithValidationConstraints
-    .filter((key) => !fields.includes(key))
-    .forEach((key) => applyIsOptionalDecorator(PartialTypeClass, key));
+  if (keysWithValidationConstraints) {
+    keysWithValidationConstraints
+      .filter((key) => !fields.includes(key))
+      .forEach((key) => applyIsOptionalDecorator(PartialTypeClass, key));
+  }
 
   inheritTransformationMetadata(classRef, PartialTypeClass);