Modal promises

class Modal {
  show<R, E = void>(getModal: ModalGetter<R, E>): ModalChainable<R, E> {
    // Injects modal into VDOM tree & returns modal chain
  }
}

// Another Framework could be in use
export type ModalGetter<R, E> = (resolvers: ModalResolvers<R, E>) => React.ReactNode;

export interface ModalResolvers<R, E> {
  resolve(r?: R): void;
  reject(e?: E): void;
  close: CloseHandler;
}

export interface ModalChainable<R, E> {
  id: string;
  then(handler: (r?: R) => void): Promise<any>;
  catch(handler: (e: E) => void): Promise<any>;
  close: CloseHandler;
  onClose(handler: CloseHandler): ModalChainable<R, E>;
}

export type CloseHandler = () => void;

/**
 * Playground
 */

declare var modal: Modal

modal.show(({ close, reject, resolve }) => (
  <div>
    <p>Modal</p>
    <button onClick={() => resolve(1)}>Resolve</button>
    <button onClick={() => reject(2)}>Reject</button>
    <button onClick={close}>Close</button>
  </div>
))
  .onClose(/** just a callback */)
  .then(/** 1 */)
  .catch(/** 2 */)

What if a Modal would have Promise-like syntax?