Use case

Once your Express application is deployed, it is important to get notified of any errors in real-time. While there are many advanced solutions for this task already, this utility middleware focuses on being minimalistic, easy setup and of course the cosy Telegram :).

Setup

1. Write to BotFather, give it a command /newbot, answer the questions, and it will give you a secret token (we call this botToken).
2. Create a channel, give it a username, and add the bot you have just created to this channel.
3. Inside of your project directory, run npm install --save express-notify-telegram.
4. Run npx express-notify-telegram. This CLI will ask you the botToken and channel's username you created in the previous steps and give you the channel's chatId.
5. Finally, in your application, add the following:

  const express = require('express');
  const telegramLogger = require('express-notify-telegram');
  
  const app = express();
  
  app.use(telegramLogger({
     botToken: '<your botToken from above>', 
     chatId: '<the chatId you got from the CLI>'
  }));
  
  // One of your endpoints
  app.get('/resource', (req, res) => {
    try {
      // Some code that throws error
    } catch(e) {
      // This will fire a notification, as it has an erroneous 500 statusCode.
      res.status(500).json(/* whatever */); 
      
      // If you want a custom error message in the notification, add the following:
      req.errorMessage = 'My custom error message';
    }
  });

Voila, from now you get an instant notification to your Telegram, and immediately fix that bug :).

API

  app.use(expressNotifyTelegram(config, opts));

Configuration (config) [required]

botToken (required)

The secret token (string) you got from BotFather.

chatId (required)

The number you got from the CLI (use the instructions above).

Options (opts) [optional]

exclude (optional)

An array of statusCodes to ignore. Example: { exclude: [404, 502] } skips all notifications for 404 and 502 statusCodes.

Defaults to [].

Note: This field has the highest priority. Even if you set enable4xx or enable5xx to true, and some values intersect with this array, those statusCodes get ignored.

enable4xx (optional)

Boolean value. If true, you will get notifications for 4xx error codes.

Defaults to true.

sound4xx (optional)

Boolean value. If true, you will get 4xx notifications with sound.

Defaults to false.

Note: This is ignored if enable4xx is false.

enable5xx (optional)

Boolean value. If true, you will get notifications for 5xx error codes.

Defaults to true.

sound5xx (optional)

Boolean value. If true, you will get 5xx notifications with sound.

Defaults to true.

Note: This is ignored if enable5xx is false.

hideSecrets (optional)

Boolean value. If true, secret fields such as passwords, secrets and tokens are hidden using a mask.

Defaults to true.

secretWords (optional)

An array of property names to be hidden with a mask.

Defaults to ['password', 'pass', 'token', 'auth', 'secret', 'passphrase', 'card']