I'm just wondering what's the reason for this seemingly awkward configuration (from Getting Started w/ Apollo Server),
const server = new ApolloServer({
// These will be defined for both new or existing servers
typeDefs,
resolvers,
});
server.applyMiddleware({ app }); // app is from an existing express app
Why is that I'm calling .applyMiddleware() and feeding it my app rather than using app.use(), it even seems from the docs that Apollo is only answering requests on /graphql wouldn't it be better to follow the Express API of,
let apollo = require('apollo-server').ApolloMiddleware
app.use( '/graphql', apollo({ typeDefs, resolvers }) );
It seems like Apollo is inverting the normal middleware flow of Express? What is the advantage of doing it the Apollo way?
I don't work with those guys, but based on the code that's there, I'm assuming it has to do with the fact that you add body parser, payload, websockets (if you opt for this) to the app, as well as a known configuration for engine health checks. The known would have to be at the root according to that specification. Also, if you use subscriptions and websockets, they listen httpServer.once('listening') , so they must have access to your application. If you were simply given one that you could mount, don't app.listen on it, since you app.listen it on your own.
Just from the inside, this is what I would expect, at least.