Is this evil?

statewaiter.js

class StateWaiter extends Promise {
  constructor(resolveStates, rejectStates) {
    let handlers;
    super((resolve, reject) => handlers = {resolve, reject});
    this._handlers = handlers;
    this._resolveStates = resolveStates;
    this._rejectStates = rejectStates;
  }
  check(state) {
    if (this._resolveStates.includes(state)) this._handlers.resolve(state);
    if (this._rejectStates.includes(state)) this._handlers.reject(state);
  }
  static [Symbol.species] = Promise;
  [Symbol.toStringTag] = 'StateWaiter';
}