fix: correctly check if custom formly form exists before saving deposit

src/app/features/deposit/components/presentationals/deposit-form/deposit-form.presentational.ts

@@ -55,10 +55,9 @@ import {
 import {
   DateUtil,
   isEmptyArray,
-  isNonEmptyString,
   isNotNullNorUndefined,
   isNullOrUndefined,
-  KeyValue,
+  KeyValue, MappingObjectUtil,
   PropertyName,
   ResourceNameSpace,
   SolidifyValidator,
@@ -239,8 +238,10 @@ export class DepositFormPresentational extends SharedAbstractFormPresentational<
     deposit.collectionBegin = DateUtil.convertToOffsetDateTimeIso8601(deposit.collectionBegin);
     deposit.collectionEnd = DateUtil.convertToOffsetDateTimeIso8601(deposit.collectionEnd);
     deposit.collectionEnd = DateUtil.convertToOffsetDateTimeIso8601(deposit.collectionEnd);
-    if (isNotNullNorUndefined(this.formFormly.value) && isNonEmptyString(this.formFormly.value)) {
+    if (isNotNullNorUndefined(this.formFormly.value) && MappingObjectUtil.size(this.formFormly.value) > 0) {
       deposit.customMetadata = JSON.stringify(this.formFormly.value);
+    } else {
+      deposit.customMetadata = null;
     }
     return deposit;
   }