util.promisify.custom

• <symbol> 可用于声明函数的自定义 Promisified 变体，请参阅 自定义 promise 化函数。

  ¥<symbol> that can be used to declare custom promisified variants of functions, see Custom promisified functions.

除了可以通过 util.promisify.custom 访问外，这个符号是 全局注册，在任何环境下都可以作为 Symbol.for('nodejs.util.promisify.custom') 访问。

¥In addition to being accessible through util.promisify.custom, this symbol is registered globally and can be accessed in any environment as Symbol.for('nodejs.util.promisify.custom').

例如，对于接受 (foo, onSuccessCallback, onErrorCallback) 的函数：

¥For example, with a function that takes in (foo, onSuccessCallback, onErrorCallback):

const kCustomPromisifiedSymbol = Symbol.for('nodejs.util.promisify.custom');

doSomething[kCustomPromisifiedSymbol] = (foo) => {
  return new Promise((resolve, reject) => {
    doSomething(foo, resolve, reject);
  });
}; 拷贝