How to work with Cron and Telegraf-bot in Nestjs?

Question

I use Telegraf and cron from @nestjs/schedule in my Nestjs app.

Below you can see my app.module:

import { Module } from '@nestjs/common';
import { BotModule } from 'src/bot/bot.module';
import { TypeOrmModule } from '@nestjs/typeorm';
import { getConnectionOptions } from 'typeorm';
import { ConfigModule } from '@nestjs/config';
import { ScheduleModule } from '@nestjs/schedule';

@Module({
  imports: [
    BotModule,
    ScheduleModule.forRoot(),
    ConfigModule.forRoot({
      isGlobal: true
    }),
    TypeOrmModule.forRootAsync({
      useFactory: async () =>
        Object.assign(await getConnectionOptions(), {
          autoLoadEntities: true
        })
    })
  ]
})
export class AppModule {}

bot.module:

import { Module } from '@nestjs/common';
import { BotService } from 'src/bot/bot.service';
import { TelegrafModule } from 'nestjs-telegraf';
import { TypeOrmModule } from '@nestjs/typeorm';
import { TelegramBot } from './entities/bot.entity';

@Module({
  imports: [
    TypeOrmModule.forFeature([TelegramBot]),
    TelegrafModule.forRootAsync({
      useFactory: () => ({
        token: process.env.BOT_TELEGRAM_TOKEN
      })
    })
  ],
  providers: [BotService]
})
export class BotModule {}

bot.service:

import { Cron } from '@nestjs/schedule';
import { InjectRepository } from '@nestjs/typeorm';
import { On, Update } from 'nestjs-telegraf';
import { Context } from 'telegraf';
import { Repository } from 'typeorm';
import { TelegramBot } from './entities/bot.entity';

@Update()
export class BotService {
  constructor(
    @InjectRepository(TelegramBot)
    private telegramRepo: Repository<TelegramBot>
  ) {}

  @On('message')
  @Cron('*/30 * * * * *')
  async message(ctx: Context): Promise<void> {
    await ctx.reply('Hello there');
  }
}

My main goal is to receive every 30 seconds message from bot into chat: "Hello there", but instead I receive nothing and messages in terminal:

[Nest] 47039   - 15/09/2021, 15:39:30   [Scheduler] TypeError: Cannot read property 'reply' of undefined +30005ms
[Nest] 47039   - 15/09/2021, 15:40:00   [Scheduler] TypeError: Cannot read property 'reply' of undefined +29997ms
[Nest] 47039   - 15/09/2021, 15:40:30   [Scheduler] TypeError: Cannot read property 'reply' of undefined +29995ms
[Nest] 47039   - 15/09/2021, 15:41:00   [Scheduler] TypeError: Cannot read property 'reply' of undefined +30003ms
[Nest] 47039   - 15/09/2021, 15:41:30   [Scheduler] TypeError: Cannot read property 'reply' of undefined +29999ms
[Nest] 47039   - 15/09/2021, 15:42:00   [Scheduler] TypeError: Cannot read property 'reply' of undefined +30002ms

So how can I use Cron for working correctly with Telegram bot?

ctx - is data which contains Context class with methods from Telegram Api — Roman Savka, Sep 15 '21 at 14:32

score 1 · Answer 1 · answered Mar 05 '22 at 03:31

The main problem into your solution, it's you don't able to use context in that scenario. This is an example how you can do that.

import { Injectable } from '@nestjs/common';
import { Cron, CronExpression } from "@nestjs/schedule";
import { Telegram } from 'telegraf';

@Injectable()
export class CronService {
  private readonly bot: Telegram = new Telegram(process.env.BOT_TOKEN);

  constructor() {}

  @Cron(CronExpression.EVERY_30_SECONDS)
  async runCronEvery30Seconds() {
    await this.bot.sendMessage('chat ID','Hello there');
  }

}

How to work with Cron and Telegraf-bot in Nestjs?

1 Answers1