Apollo-client: Could not find __typename__ on Fragment

[MJones180]

Throughout my code I use fragments to break up the data requirements. However, in the header I have a simple query:

query: gql`
  query HeaderUser {
    me {
      nameFirst
      nameLast
    }
  }
`

Sometimes this Query returns null ({ me: null }) and Apollo Client raises a really annoying error each time: You're using fragments in your queries, but either don't have the addTypename: true option set in Apollo Client, or you are trying to write a fragment to the store without the __typename. Please turn on the addTypename option and include __typename when writing fragments so that Apollo Client can accurately match fragments. and Could not find __typename on Fragment Query {me: null}. This is really weird because I am not even using fragments in this case. Is there a way to remove this error?

Version

• [email protected]

EDIT
I would also like to add that the error comes up on some responses that even do contain the __fragment field.

[ikatun]

You should make sure that every query you're writing includes id field and that you haven't set addTypename: false option for apollo client.

My guess is that you're probably fetching a user/profile (or whatever the type for me query is) in some query other than me without id and that apollo cache gets confused because it can't normalize state without ids.

I suggest rewriting this query to

query: gql`
  query HeaderUser {
    me {
      id
      nameFirst
      nameLast
    }
  }
`

and then add id to every query (and also to every field and subfield of every query) used in the app even if you're not explicitly using it.

[hwillson]

The explanation outlined in https://github.com/apollographql/apollo-client/issues/3249#issuecomment-408583967 sounds quite reasonable. If that doesn't help, please provide a small runnable reproduction that clearly demonstrates this issue. Thanks!