Fix undefined array crash when using useArrayField

Author: CodeStix

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.2.1 (25/06/2021)
+
+-   Fix crash on undefined/null array when using useArrayField.
+
 # 2.2.0 (9/05/2021)
 
 -   `innerRef` prop on `Field` and `FieldError`

src/hooks.ts

@@ -157,7 +157,7 @@ export function useArrayField<
     useEffect(() => {
         let id = parentForm.listen(name, () => {
             let val = parentForm.values[name] as any;
-            if (val.length !== oldLength.current) {
+            if (Array.isArray(val) && val.length !== oldLength.current) {
                 setRender((i) => i + 1);
                 oldLength.current = val.length;
             }