Returning an object from a callback using async/await

问题

I can't resolve this question with the answers to this question because there are differences in the code.

I want to return an object out of a callback. When I run the below code, the log of the body object looks as expected. It appears to be the correct JSON object containing the response I want from the server: name, email, website, etc.

But the result object appears to contain information about the request itself instead of the response object.

How do I return the body object so that I can access it from the result variable?

const request = require('request'); // npm i request -s

module.exports = async config => {
  ...

  const result = await request.get( url, options,
    ( error, response, body, ) => {
      console.log( 'body', body, ); // I want the other log to look like this log.
      return body;
    }
  );

  console.log( 'result', result, ); // I want this log to look like the above log.
  // In other words, I want the below line to be the name, email, website JSON object
  // contained in the body
  return result;
}

This is what I want from result.

console.log( 'body', body, );

body {
  "name": "foo",
  "email": "foo@example.com",
  "website": "www.example.com",
  ...
}

This is what I actually get from result.

console.log( 'result', result, );

result Request {
  _events: [Object: null prototype] {
    error: [Function: bound ],
    complete: [Function: bound ],
    pipe: [Function]
  },
  _eventsCount: 3,
  _maxListeners: undefined,
  uri: Url {
    protocol: 'https:',
    slashes: true,
    auth: null,
    host: 'api.example.com',
    port: 443,
    hostname: 'api.example.com',
    hash: null,
  },
  callback: [Function],
  method: 'GET',
  readable: true,
  writable: true,
  explicitMethod: true,
  _qs: Querystring {
    request: [Circular],
    lib: { formats: [Object], parse: [Function], stringify: [Function] },
    useQuerystring: undefined,
    parseOptions: {},
    stringifyOptions: {}
  },
  _auth: Auth {
    request: [Circular],

回答1:

Use Promise:

const result = await new Promise((resolve) => {
  request.get(url, options, (error, response, body) => {
      console.log( 'body', body );
      resolve(body);
    });
});

Edit:

or you can install https://github.com/request/request-promise

回答2:

request.get() does NOT return a promise, therefore await on it does nothing useful. If I had a nickel for every time I've responded to this question, I'd have a lot of nickels. await has no magic. All it does is wait on a promise. It doesn't do ANYTHING if you don't pass it a promise.

You may not know, but the request module and its derivatives are in maintenance mode (no new features, only bug fixes). You can either use the request-promise module and then get rid of the callback or you can switch to a newer module that is being actively developed such as the got module. That would be my recommendation:

const got = require('got');

module.exports = async config => {
  ...

  const result = await got(url, options);

  console.log( 'result', result ); // I want this log to look like the above log.
  // In other words, I want the below line to be the name, email, website JSON object
  // contained in the body
  return result;
}

And, I hope you realize that ALL async functions return a promise so the caller of this function will have to either use await or .then() on the returned promise in order to get the result out of the promise.

---

If you wanted to stay with the request library, you can use request-promise to get an already promisified version of the library:

const rp = require('request-promise');

module.exports = async config => {
  ...

  const result = await rp(url, options);

  console.log( 'result', result ); // I want this log to look like the above log.
  // In other words, I want the below line to be the name, email, website JSON object
  // contained in the body
  return result;
}

来源：https://stackoverflow.com/questions/59759629/returning-an-object-from-a-callback-using-async-await