Reconcile a store, but ignore properties if they are undefined in the data source

[Tronikelis]

My problem

I am syncing my store from an external api that is not guaranteed to always return all properties, if it does not return all properties the reconcile sets them as undefined, no matter if it is merge: true / false (I still don't really get the difference, but this doesnt matter now). So the store has undefined and the Type is not defined as undefined, so my app breaks

Current "workaround"

import { merge } from "merge-anything";
import { reconcile, ReconcileOptions } from "solid-js/store";

/**
 * reconciles only the changed properties from `newData`
 * the difference from default `reconcile` is that this method keeps default properties
 * if they do not exist in `newData`, but default reconcile deletes them
 */
export default function reconcileMerge<T>(
    initialValue: T,
    newValue: T,
    options?: ReconcileOptions
) {
    return reconcile(merge(initialValue, newValue), options);
}

Proposed solution

Maybe a new option ignoreUndefined keepDefault in the reconcile?