Better error for overwriting object with no id

[tizmagik]

Carry over from

apollographql/apollo-client#819

[dcecile]

As a workaround to debug my missing ID, I added console errors to my ID function:

const cache = new InMemoryCache({
    dataIdFromObject: object => {
        if (
            !object.id !==
            (object.__typename.endsWith("Connection") ||
                object.__typename.endsWith("Edge") ||
                object.__typename.endsWith("Mutation"))
        ) {
            if (!object.id) {
                console.error("Missing id for GraphQL data", object)
            } else {
                console.error("Unexpected id for GraphQL data", object)
            }
        }
        return object.id
    },
})

The whole object together with the timing of the error message were enough to narrow down the queries and find the missing ID.