promisify [承诺]

转换异步功能以返回承诺。

In Node 8+, you can use util.promisify

使用 currying 返回函数返回 Promise 该调用原始功能。 使用 ...rest 运算符传递所有参数。

typescript

const promisify =
  (func: Function) =>
  (...args: any[]) =>
    new Promise((resolve, reject) =>
      func(...args, (err: Error, result: any) =>
        err ? reject(err) : resolve(result)
      )
    );

typescript

const delay = promisify((d, cb) => setTimeout(cb, d));
delay(2000).then(() => console.log("Hi!")); // // Promise resolves after 2s