Node.js slack logger example

slack-logger.js

const { IncomingWebhook } = require('@slack/client');

let sendToSlack;

const t = () => (new Date()).toISOString();

if (process.env.SLACK_LOGGING_WEBHOOK_URL) {
  const slack = new IncomingWebhook(process.env.SLACK_LOGGING_WEBHOOK_URL);
  const handler = err => {
    if (err) {
      console.error(`Error sending message to slack: ${err}`);
    }
  };
  sendToSlack = args => {
    slack.send({
      iconEmoji: ':nodejs:',
      username: `${process.env.API_ENDPOINT} NODE_ENV=${process.env.NODE_ENV}`,
      text: args.join(' ')
    }, handler);
  };
} else {
  sendToSlack = () => {};
}

module.exports = {
  error: (err, ...args) => {
    const msg = [
      (err && err.status) || '',
      (err && err.stack && `\n${err.stack}\n`) || err,
      ...args
    ];
    sendToSlack([':red-bar:', t(), ...msg]);
    console.error(...msg);
  },

  log: (...args) => {
    sendToSlack([':grey-bar:', t(), ...args]);
    console.log(...args);
  }
};