Function whenCalled

testing/helpers/service.js:69–74

(spy, opt_callCount = 1)

 * @return {!Promise}
 */
export function whenCalled(spy, opt_callCount = 1) {
  return poll(
    `Spy was called ${opt_callCount} times`,
    () => spy.callCount === opt_callCount
  );
}

/**
 * Resolves a promise when the callback returns a truthy value.