覆盖预定义的 GraphQLSchema 解析器 (Apollo)

问题描述

我正在为现有的 REST API 设置 GraphQL 包装器。 我决定使用的工具可让您轻松定义对 REST API 的所有调用的方式，并为每个端点生成解析器。

我希望能够用自定义逻辑覆盖某些查询或突变，我预感使用一些 graphql-tool 很容易实现，但我还没有登陆它。

下面是设置服务器的主要代码，然后是用于查询 REST API 的获取客户端，然后是我希望能够扩展某些端点的方式。

// The main server setup thus far

import express from "express";
import cors from "cors";
import { createServer } from "http";

import { callBackend } from "./connections";

import { createSchema } from "swagger-to-graphql";
import { ApolloServer } from "apollo-server-express";
import { generateTypes } from "./utils";
import { parse, printSchema } from "graphql";

const port = process.env.PORT || 4000;

(async () => {
  const app = express();
  const server = createServer(app);

  app.use(cors({ origin: "*", credentials: true }));

  const schema = await createSchema({
    swaggerSchema: "URL_POINTING_TO_SWAGGER_DEFINITION",
    callBackend,
  });

  await generateTypes(parse(printSchema(schema)));

  server.listen(port, () => {
    console.log("Server has launched..");
  });

  const apollo = new ApolloServer({
    introspection: true,
    debug: true,
    tracing: true,
    context: ({ req, res }) => ({ req, res }),
    schema,
  });

  apollo.applyMiddleware({ app, cors: { origin: "*", credentials: false } });
})();

_________________________________________

// The callBackend function being imported in the previous code.

export async function callBackend({
  context,
  requestOptions,
}: CallBackendArguments<Request>) {
  return axios({
    method: requestOptions.method,
    url: `URL${requestOptions.path}`,
    headers: requestOptions.headers,
    params: requestOptions.query,
    data: requestOptions.body,
  });
}

_________________________________________

// The way in which I would like to be able to override certain calls being generated by the
// swagger tools createSchema function. These ideally just get passed into ApolloServer's args as 
// { resolvers: [CustomerResolvers, ...etc] }

export const CustomerResolvers = {
  Query: {
    get_customers(...args) {
     // some additional logic
    },
  },
};