Deleting data with `writeFragment`

Intended outcome: I’d like to be able to selectively remove data from the query store via the imperative API (i.e. client.writeFragment and client.writeQuery). Something like:

client.writeFragment({
  fragment,
  id,
  data: null
});

or

client.writeFragment({
  fragment,
  id,
  data: {}
});

Is there a way to accomplish this?

Actual outcome: If I try either of the two above constructions, the data still exists and can be read back out. You can see this in this example.

How to reproduce the issue: Here’s a complete code example:

import ApolloClient from 'apollo-client';
import gql from 'graphql-tag';

const client = new ApolloClient.ApolloClient({
  dataIdFromObject(obj) { return obj.id; },
  addTypeName: true
});
const fragment = gql`fragment update on person{ 
  id
  __typename
}`;
const id = 'person-01';
const __typename = '__typename';

client.writeFragment({
  fragment,
  id,
  data: {
    id,
    __typename
  }
});
client.readFragment({
  fragment,
  id
}); // should get { __typename: '__typename', id: 'person-1' }

client.writeFragment({
  fragment,
  id,
  data: null
});
client.readFragment({
  fragment,
  id
}); // fragment is still there; I'd expect `null`

Perhaps there is just some syntax that I’m missing?

What I’ve done currently—and am really not a fan of—is take the old mutation delete reducers code and stick it in my code base as follows:

    const state = client.store.getState().apollo;
    state.data = mutationResultDeleteReducer(state.data, {
      behavior: {
        dataId: action.id
      }
    });

That seems to work, but is obviously quite fragile in terms of the store format, etc.

[skosch]

Would it be an option (among others) to provide a simple way to delete by object id? That would probably cover the most common use case.

[helfer]

@skosch it isn’t possible right now, but we’re thinking of adding an API for doing invalidations and deleting data in the store. Let’s continue all discussions related to that on #621