Slack bot that listens for GitHub's PR URLs and finds out if the PR was merged or not

slackbot-github-pr.js

const SlackBot = require('slackbots')
const GitHubApi = require('github')

const github = new GitHubApi({
  version: '3.0.0',
  protocol: 'https'
})

const bot = new SlackBot({
  token: 'xoxb-000000000000-aaaaaaaaaaaaaaaaaaaaaaaa',
  name: '@github'
})

bot.on('start', function () {
  console.log('Bot started')
})

bot.on('message', function ({ type, text, channel }) {
  if (type !== 'message') {
    return
  }

  const regexp = /(<https:\/\/github.com\/([\w-_]+)\/([\w-_]+)\/pull\/(\d+)>)/gm
  let result
  while (result = regexp.exec(text)) { // eslint-disable-line no-cond-assign
    const [fullMatch, match, owner, repo, number] = result // eslint-disable-line no-unused-vars

    github.pullRequests.get({ owner, repo, number }).then(function ({ merged, mergeable }) {
      let message = `It looks like ${owner}/${repo}/pull/${number}`
      if (merged) {
        message += ' is already merged!'
      } else if (mergeable) {
        message += ' is ready to merge!'
      } else {
        message += ' cannot be to merged...'
      }
      bot.postMessage(channel, message).then(function () {
        console.log('PR data sent')
      }).catch(function (err) {
        console.error(`Could not post message: ${err.message}`)
      })
    }).catch(function (err) {
      console.error(`Could not get data for PR: ${err.message}`)
    })
  }
})

bot.on('error', function (err) {
  console.error(`Bot error: ${err.message}`)
})