Reading request headers from type-graphql resolvers with ApolloServer

I am following this example that uses Prisma ORM, ApolloServer and type-graphql to make a simple blog web app.

I want to inspect the HTTP request headers and I'm having trouble working out how to access the ApolloServer context.headers in a type-graphql resolver such as this:

  @Query((returns) => Post, { nullable: true })
  async postById(@Arg('id') id: number, @Ctx() ctx: Context) {
    return ctx.prisma.post.findUnique({
      where: { id },
    })
  }

The ApolloServer is set up here like this:

new ApolloServer({ schema, context: context }).listen({ port: 4000 }, () =>
    console.log(`Server ready at: http://localhost:4000`), )

But the @Ctx() ctx: Context referenced in the resolver above is only the Prisma context (defined here) not the ApolloServer context. If I log the keys for the ctx object I get: [ 'prisma', '_extensionStack' ]

In past ApolloServer projects that do not use type-graphql decorators I have accessed the ApolloServer context like this:

postById: async (_, { id }, apolloServerContext) => {... console.log(apolloServerContext.headers)

How can I access the request headers from the resolver that uses type-graphql decorators?

Solution

You can use IncomingMessage as the type of the context object in the Resolver query.

But first, you need to pass context parameter to ApolloServer's constructor like the following:

new ApolloServer({
  schema: schema,
  context: ({ req }) => {
    return req;
  },
 });

Then you will be able to consume it in the Resolver like this:

import { Ctx, Query, Resolver } from "type-graphql";
import { IncomingMessage } from "http";

@Resolver()
export class TestResolver {
  constructor(private readonly service: TestService) {}

  @Query(() => Data, { nullable: true })
  async getDataForUser(@Ctx() context: IncomingMessage): Promise<Data> {
    const headers = context.headers;
    return await this.service.fetchData();
  }
}