515 - race() - javascript

[jsartisan]

index.js

export function race(funcs) {
  return (callback) => {
    let done = false;

    if (funcs.length === 0) {
      callback(null, undefined);
    }

    funcs.forEach((fn) => {
      fn((err, data) => {
        if (!done) {
          done = true;
          callback(err, data);
        }
      });
    });
  };
}