logout.ts

logout(): Promise<void> {
  if (this.store.local.getItem(AUTH_STORAGE_KEY) || this.store.session.getItem(AUTH_STORAGE_KEY)) {
    return this
      .api
      .post('Citizens/logout', {})
      .catch(err => {
        this.log.error(Error(`Unable to logout - response: ${res.status}`));
        return Observable.of(null);
      })
      .do(() => {
        this.authentication = null;
        this.store.local.removeItem(AUTH_STORAGE_KEY);
        this.store.session.removeItem(AUTH_STORAGE_KEY);
      })
      .toPromise();
  } else {
    return Promise.resolve();
  }
}