unenv/runtime/node/util/_promisify.mjs

`unenv` is a framework-agnostic system that allows converting JavaScript code to be platform agnostic and work in any environment including Browsers, Workers, Node.js, or JavaScript runtime.

const customSymbol = Symbol("customPromisify");
function _promisify(fn) {
  if (fn[customSymbol]) {
    return fn[customSymbol];
  }
  return function(...args) {
    return new Promise((resolve, reject) => {
      try {
        fn.call(this, ...args, (err, val) => {
          if (err) {
            return reject(err);
          }
          resolve(val);
        });
      } catch (error) {
        reject(error);
      }
    });
  };
}
_promisify.custom = customSymbol;
export const promisify = _promisify;