optional.js

"use strict";

class Optional {
  constructor(value, isError) {
    this._value = value;
    this._ok = !isError;
  }
  [Symbol.toPrimitive](hint) {
    switch (hint) {
      case "number": return this._ok ? 1 : 0;
      case "string": return this._ok ? "1" : "";
      default: return this._ok;
    }
  }
  get value() {
    return this._value;
  }
}

module.exports = Optional;