无法阅读财产＆＃39;然后＆＃39;未定义，函数不是异步

Question

我不确定为什么会发生这种情况，我试过asycn / await，bluebrid，内置的承诺，什么都行不通，这是我的代码：

const Promise = require('bluebird');
const mongoose = require('bluebird').promisifyAll(require('mongoose'));
const bar = require('./config/models/bar');

router.get('/foo', function(req, res) {
  getCollection('foo').then(data => res.sendStatus(200).json(data))
});

function getCollection() {
  new Promise(function(resolve, reject) {
    bar.findAsync({}, function(err, result) {
      if (err) {
        console.log(err);
      }
      console.log(result) //This prints the correct result to log
      resolve(result)
    })
  });
}

每当我转到/foo时，我都会TypeError: Cannot read property 'then' of undefined

Answer 1

您需要从Promise返回getCollection。

function getCollection() {
  return new Promise(function(resolve, reject) {
    bar.findAsync({}, function(err, result) {
      if (err) {
        console.log(err);
      }
      console.log(result) //This prints the correct result to log
      resolve(result)
    })
  });
}