/**
 * Inverts the given promise - i.e. throws an error if it completes successfully and returns the
 * error if it throws one.
 *
 * @param {Promise} promise - the promise to invert
 * @param {string} message - the message to throw if the promise resolves
 * @returns the error thrown by the promise
 */
// tslint:disable-next-line:no-any (returns the rejection which is untyped)
export async function invert(promise: Promise<any>, message?: string): Promise<any> {
  message = message || 'Expected promise to reject';
  return promise.then(
    () => {
      throw new Error(message);
    },
    err => err,
  );
}