Retrieving non-header context from Apollo Server

Question

I keep seeing examples about setting context on Apollo Client like this :

new ApolloClient({
    uri: '...',
    request(operation) {
      const currentUser = readStore<CurrentUser>("currentUser");
      currentUser &&
        operation.setContext({
          headers: { authorization: currentUser.token },
          other: "things"
        });
    }
  });
}

With things that go to the request headers, and "other" things. Yet after more than 2h of research, I couldn't find one example of that other context data being retrieved on the other end, on Apollo Server.

It seems like all the examples are about authorization tokens, but how to I retrieve the rest, say using apollo-server-express ?

Here is what I have so far :

const apollo = new ApolloServer({
  typeDefs,
  resolvers,
  context({ req }): Context {
    const currentUser =
      (req.headers.authorization &&
        (jwt.verify(
          req.headers.authorization,
          process.env.JWTSIGN
        ) as Context["currentUser"])) ||
      null;

    // Ok for req.headers.authorization, how to I get "other: things" ?

    return {
      ip: req.ip,
      currentUser
    };
  }
});

The context function here only gets a req and a res object from Express. After some logs, it doesn't seem to contain the data I want.

Thank you.

Answer 1

The only reason it appears headers are shared in the example you shared is because ApolloClient uses the headers value inside its context to populate the HTTP headers it sends when making a request. Those headers are then parsed by express and made available on the req object. The context used by ApolloClient is strictly client-side. The context used by ApolloServer is strictly server-side. You can't use ApolloClient's context to pass arbitrary values to your server -- you should utilize headers or arguments inside your GraphQL query for that.