async / await不适用于promisify

Question

我正在尝试使用util.promisify函数，但我的代码不起作用。我想我不明白承诺/宣传是如何运作的。如果我使用promisify我的代码可以使用，但如果我使用const oembed = require('oembed-auto'); const { promisify } = require('util'); const test = () => { return new Promise((resolve, reject) => { oembed("http://www.youtube.com/watch?v=9bZkp7q19f0", function (err, data) { resolve(data); }); }); }; module.exports.getAllInterests = async () => { const data = await test(); console.log(data); return data; }; 则不然。

如果我运行此代码：

{ html: '<iframe width="480" height="270" src="https://www.youtube.com/embed/9bZkp7q19f0?feature=oembed" frameborder="0" allowfullscreen></iframe>',
  author_url: 'https://www.youtube.com/user/officialpsy',
  thumbnail_url: 'https://i.ytimg.com/vi/9bZkp7q19f0/hqdefault.jpg',
  width: 480,
  height: 270,
  author_name: 'officialpsy',
  thumbnail_height: 360,
  title: 'PSY - GANGNAM STYLE(강남스타일) M/V',
  version: '1.0',
  provider_url: 'https://www.youtube.com/',
  thumbnail_width: 480,
  type: 'video',
  provider_name: 'YouTube' }

我得到了预期的结果：

const oembed = require('oembed-auto');
const { promisify } = require('util');

const test = () => {
  promisify(oembed)("http://www.youtube.com/watch?v=9bZkp7q19f0").then((data) => {
    resolve(data);
  });
};

module.exports.getAllInterests = async () => {
  const data = await test();
  console.log(data);
  return data;
};

如果我运行此代码：

undefined
(node:66423) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): ReferenceError: resolve is not defined
(node:66423) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Async / await不起作用，我得到：

Entity1

Answer 1

return test resolve undefined内.then() const test = () => promisify(oembed)("http://www.youtube.com/watch?v=9bZkp7q19f0"); 内没有值module.exports.getAllInterests = async () => { let data; try { data = await test(); console.log(data); } catch (err) { console.error(err); throw err; } return data; };

getAllInterests().then(res => console.log(res), err => console.err(err));

TestServer1

ping TestServer1 - success
telnet TestServer1 1433 - failed

Answer 2

您的测试函数必须是Async，并且您只需要在promisify（embeded）上使用Await。请注意，您需要在异步函数内使用getAllInterests，在这种情况下，我将其放在异步闭包内。 （我自己测试了代码，并且性能良好）。而且调试和维护也更灵活。

const oembed = require('oembed-auto');
const { promisify } = require('util');

const test = async () => {
  return await promisify(oembed)("http://www.youtube.com/watch?v=9bZkp7q19f0");
}

const getAllInterests = async () => {
  const data = await test();
  console.log(data);
  return data;
};

(async ()=> {
    await getAllInterests();
})();