Apollo Server with merging schemas

index.js

// the same imports as it was in boilerplate-graphql-koa-server-external
const { loadSchema } = require('@graphql-tools/load');
const { UrlLoader } = require('@graphql-tools/url-loader');
const { makeExecutableSchema, mergeSchemas } = require('@graphql-tools/schema');

const EXTERNAL_ENDPOINT = 'http://localhost:4000/api/v1/graphql';

async function server({ typeDefs, resolvers }) {
  // app and httpServer the same like in boilerplate-graphql-koa-server-external

  const internalSchema = makeExecutableSchema({
    typeDefs,
    resolvers,
  });

  const schemas = [internalSchema];

  try {
    const externalSchema = await loadSchema(EXTERNAL_ENDPOINT, {
      loaders: [new UrlLoader()],
    });
    schemas.push(externalSchema);
  } catch {
    console.warn('⚠️️ External Schema has not been loaded');
  }

  const apolloServer = new ApolloServer({
    introspection: true,
    schema: mergeSchemas({
      schemas,
    }),
  });

  // the same start server how at boilerplate-graphql-koa-server-external
  console.log(`🚀 Server ready at http://localhost:${process.env.PORT}${apolloServer.graphqlPath}`);

  return { apolloServer, app };
}

// the same server call like in boilerplate-graphql-koa-server-external