Function resetDb

packages/misc/angular-in-memory-web-api/src/backend-service.ts:723–737

* Tell your in-mem "database" to reset. * returns Observable of the database because resetting it could be async

(reqInfo?: RequestInfo)

   * returns Observable of the database because resetting it could be async
   */
  protected resetDb(reqInfo?: RequestInfo): Observable<boolean> {
    this.dbReadySubject && this.dbReadySubject.next(false);
    const db = this.inMemDbService.createDb(reqInfo);
    const db$ =
      db instanceof Observable
        ? db
        : typeof (db as any).then === 'function'
          ? from(db as Promise<any>)
          : of(db);
    db$.pipe(first()).subscribe((d: {}) => {
      this.db = d;
      this.dbReadySubject && this.dbReadySubject.next(true);
    });
    return this.dbReady;
  }
}