如何在 ApolloServer 中添加响应头？

Question

我正在使用 graphql ApolloServer 并为 Apolloserver 使用以下内容

server.applyMiddleware({ app, path: '/graphql' });

我需要在响应头中传递解析器返回的错误。

我阅读了文档，但看起来我们无法在上述中间件之后添加另一个中间件。

我还尝试在初始化服务器时添加formatResponse，但这里的对象不是我可以更改错误标头的实际 http 响应。

const server = new ApolloServer({
  schema,
  validationRules: [depthLimit(7)],
  playground: process.env.NODE_ENV !== 'production',
  debug: process.env.NODE_ENV !== 'production',
  formatError: err => {
    // Don't give the specific errors to the client.
    if (err.message.startsWith('Database Error: ') || err.message.startsWith('connect')) {
      return new Error('Internal server error');
    }

    // Otherwise return the original error. The error can also
    // be manipulated in other ways, so long as it's returned.
    return err;
  },
  formatResponse: (res:any,options:any) => {

   // can't set headers here as it is not the http response object.


    return res;
  }
});

是否有任何选项可以做到这一点？

Answer 1

const buildContext = async ({ res, req }) =>
  // Attach additional properties to context if needed
  ({
    user: req.user,
    res,
    req
  });

与“apollo-server-express”集成包一起使用。

import { ApolloServer } = 'apollo-server-express';
...
const server = new ApolloServer({
  // schema, etc...
  context: ({ res, req }) => buildContext({ res, req }),
  formatResponse: (response, query ) => {
    const { context } = query;
    const { res, req: request } = context; // http response and request
    // now you can set http response headers
   // res.set(...)


    const { data } = response;  // graphql response's data
    const { headers = {} } = request; // http request headers
    return response; // graphql response
  },
});

Answer 2

new ApolloServer({
  context: ({res}) => {
    res.header('key', 'value')
  }
})

参考：https://www.apollographql.com/docs/apollo-server/api/apollo-server/