Count slack messages by bot in a channel

index.js

'use strict';

const WebClient = require('@slack/client').WebClient;

const TOKEN = process.env.SLACK_TOKEN;
const CHANNEL_NAME = 'cofftentful';
const BOT_ID = 'B4XNQQK3M';

const web = new WebClient(TOKEN);

function getHistory(channelId) {
  const messages = [];

  function gatherMessages(info) {
    messages.push(...info.messages);

    if (info.has_more) {
      const lastetTs = info.messages[info.messages.length - 1].ts;
      console.log(lastetTs);

      return web.channels.history(channelId, {latest: lastetTs})
        .then(gatherMessages)
    } else {
      return messages;
    }
  }

  return web.channels.history(channelId)
    .then(gatherMessages)
}

web.channels.list()
  .then(info => info.channels)
  .then(channels => {
    for (const channel of channels) {
      if (channel.name === CHANNEL_NAME) {
        return channel.id;
      }
    }

    throw new Error('Channel not found')
  })
  .then(channelId => {
    return getHistory(channelId)
  })
  .then(history => {
    return history.filter(function (message) {
      return message.subtype === 'bot_message' && message.bot_id === BOT_ID;
    })
  })
  .then(history => {
    return console.log(history.length)
  });