NestJS TDD (입고 알림) - 4. Scheduler

5초마다 재고 상태를 확인해주는 스케쥴링을 구해봅시다.

4-1. Setting Up Task Scheduler

우선 필요한 패키지를 설치 합시다.

> npm install --save @nestjs/schedule
> npm install --save-dev @types/cron

참고

NestJS Docs - Task Scheduling

4-2. Scheduler

매 5초마다 request를 요청하는 scheduler를 만든다. (넘 심한가...?)

@Injectable()
export class TaskSchedulerService {
  private static readonly logger = new Logger(TaskSchedulerService.name);

  constructor(
    private readonly watcherService: WatcherService,
    private readonly schedulerRegistry: SchedulerRegistry,
  ) {}

  @Cron(CronExpression.EVERY_5_SECONDS, {
    name: 'V28UE_WATCHING',
  })
  async handleWatchingStock() {
    const requestUrl =
      'https://www.jooyonshop.co.kr/goods/goods_view.php?goodsNo=1000000165';
    // TaskSchedulerService.logger.debug('아이고난!');
    const resultRequest = await this.watcherService.getHttpRequest(requestUrl);
    const isSoldOut =
      this.watcherService.parseHtmlAndCheckIsSoldOut(resultRequest);

    if (!isSoldOut) {
      const job = this.schedulerRegistry.getCronJob('V28UE_WATCHING');
      job.stop();
      TaskSchedulerService.logger.debug('떳따!');
      this.watcherService.notify({ text: 'Buy It! Hurry Up!' });
    } else {
      TaskSchedulerService.logger.debug('아직 안떴따');
    }
  }
}

참고

NestJS Docs - Scheduler