Merge function never brings existing value for an identified fragment on cache

I have 2 queries which I use with the same variable/input, like this:

query GET_MY_DATA_FOO($id: String!) {
  foo(id: $id) {
    id
    ...Impagados
  }
}

query GET_MY_DATA_BAR($id: String!) {
  bar(id: $id) {
    id
    ...Impagados
  }
}

fragment Impagados on Impagados {
  impagados {
    id
    __typename
    ebe {
      error
      nota
    }
    icired {
      error
      nota
    }
    rai {
      error
      nota
    }
  }
}

I use it, let’s say:

const { data, error, loading } = useQuery(GET_MY_DATA_FOO, {
  variables: { id: '1' },
});

const { data, error, loading } = useQuery(GET_MY_DATA_BAR, {
  variables: { id: '1' },
});

Intended outcome:

I would expect my merge function to bring existing data from previous queries. This sample merge function triggers ok:

merge(existing = {}, incoming = {}, { cache, toReference, readField }) {
  if (existing) return { ...existing };
  return { ...incoming };
}

Actual outcome:

After GET_MY_DATA_FOO query was launched, retrieved the data, and triggered the merge function (with existing value undefined, of course), I launch GET_MY_DATA_BAR which comes with existing value undefined as well.

I have tried removing the id field from the fragment, so it wouldn’t become an entity, so to say, and I could maybe access the same fragment already cached on the other query. But I cannot find a way to do it.

If I keep the id field there, the merge function triggers, there is no existing value and trying to read the fragment from cache already brings the new value that was already written on cache:

const existing = cache.readFragment({
  id: incoming.__ref,
  fragment: gql`
    fragment Impagados on Impagados {
      id
      ebe {
        error
        nota
      }
      icired {
        error
        nota
      }
      rai {
        error
        nota
      }
    }
  `,
});

Versions

System: OS: Linux 5.4 Ubuntu 20.04.3 LTS (Focal Fossa) Binaries: Node: 14.15.0 - ~/.nvm/versions/node/v14.15.0/bin/node Yarn: 1.22.15 - ~/.nvm/versions/node/v14.15.0/bin/yarn npm: 8.1.3 - ~/.nvm/versions/node/v14.15.0/bin/npm Browsers: Chrome: 94.0.4606.71 npmPackages: @apollo/client: ~3.2.5 => 3.2.9

[Richacinas]

Thanks for your answer.

I’m not sure if this is a typo or an explanation…

Sorry, that was a typo.

What I’m trying to achieve is that, when the second query is launched, I can read the value that I got on the first query for this fragment. Once I have that, I would like to choose which one I keep.

Should I keep the __typename and id fields on this fragment in order to to that, or should I toss id so they stay separate? How could I get the value of the other fragment either way?

Thanks a lot

[Richacinas]

Let me have a proper read about this again… I would like to keep talking about it as well.