SSJS to copy DEs (especially synchronized DEs)

copyDE.txt

%%[ 
    VAR @Result
]%%
  <script runat="server">
Platform.Load("Core", "1.1.1");    
    try {      
      var DEtoCopy = DataExtension.Init("Contact_Salesforce");
      var jsonArray = DEtoCopy.Fields.Retrieve();
      
      for(var i = 0; i < jsonArray.length; i++) {
          delete jsonArray[i]['ObjectID'];
          jsonArray[i]['IsRequired'] = false;
          if(jsonArray[i]['IsPrimaryKey'] == true)
              jsonArray[i]['IsRequired'] = true;
          if(jsonArray[i]['Name'] == '_ContactKey')
              jsonArray[i]['Name'] = 'ContactKey';
          if(jsonArray[i]['FieldType'] == 'Decimal') {
             jsonArray[i]['FieldType'] = 'Text';
             jsonArray[i]['MaxLength'] = 50;
          };
      };
      var deObj = {"CustomerKey" : "SyncedContactsSalesforce","Name" : "SyncedContactsSalesforce","Fields" : jsonArray};
                   Write(Stringify(deObj));
      var newDE = DataExtension.Add(deObj);
    } catch (ex) {
        Write("An error has occurred: " + Stringify(ex));
        Write("   deObj: " + Stringify(deObj));
        Variable.SetValue("@Result", Stringify(ex));
    }
</script>