Handler with callback to Slack

handler.js

const { WebClient } = require('@slack/web-api');

const wc = new WebClient(process.env.SLACK_TOKEN);

const handler = async (event) => {
  console.log('Received request', event);
  const { body } = event;
  
  if (body.challenge) {
    return {
      statusCode: 200,
      headers: { 'Content-Type': 'text/plain' },
      body: body.challenge,
    };
  }

  // Ignore messages from bot in IM
  const { channel_type: channelType, bot_id: botId } = body.event;
  if (channelType === 'im' && botId) {
    return { statusCode: 200 };
  }

  if (body.event) {
    const { channel } = body.event;
    const text = 'Hej Världen';
    return wc.chat.postMessage({ channel, text });
  }

  return { statusCode: 200 };
};

module.exports = { handler };