Can't get dataIdFromObject to work with a meteor/apollo backend and react-native

I’ve tried this:

const dataIdFromObject = (result) => {
  if (result._id && result.__typename) {
    const dataId = result.__typename + result._id;
    return dataId;
  return null;

and just this:

dataIdFromObject: o => o._id

but it doesn’t seem to be helping with updating my cache. And I’m a little overwhelmed at all the ways to update my cache. I’m trying to a simple ListViewScreen => CreateFormScreen => back to ListViewScreen showing the new record added but dataIdFromObject doesn’t seem to be triggering anything and I’m trying to figure out which of he 3-4 update options is best here.

Got my answers here:

Just a poor understanding on my part.