Why use IntrospectionFragmentMatcher?

Question

Is there any reason to use IntrospectionFragmentMatcher to determine concrete types of values returned from interface and union fields?

I'm talking about apollo-client. I'm using InMemoryCache with addTypename: true, so the type is known the moment the client gets the response.

Meanwhile my console is plagued with warnings like these:

The only reason I see the documentation hint at is response validation. But why validate the server-sent response at all? If the server is not worth trusting, validation is useless anyway.

Answer 1

The warnings seem to be a bug in apollo. https://github.com/apollographql/apollo-client/issues/3397