index.js

'use strict'

module.exports = function(ctx, cb) {
  const GitHubApi = require('github')
  const co = require('co')
  const gh4 = require('axios').create({
    baseURL: 'https://api.github.com/',
    headers: {
      Authorization: `Bearer ${ctx.secrets.GH_TOKEN}`
    }
  })

  const github = new GitHubApi({
    headers: { "user-agent": "React Bangkok Review Bot" },
    timeout: 10000
  })

  github.authenticate({
    type: "token",
    token: ctx.secrets.GH_TOKEN
  })

  const BUILD_FAILED = '✖︎ Build failed'
  const ISSUE_TAG_MISSING = '✖︎ Issue tag missing'
  const READY_TO_MERGE = '✔︎ Ready to merge'
  const TICKET_ISSUED = 'ticketing/issued'
  const TICKET_APPLICATION_PENDING = 'ticketing/application-pending'
  const TICKET_ISSUE_PENDING = 'ticketing/issue-pending'
  const owner = 'reactbkk'
  const repo = '2.0.0'

  function main () {
    return co(function* () {
      yield * checkOpenPullRequests()
      yield * checkClosedPullRequests()
    })
  }

  function * checkOpenPullRequests () {
    const pulls = yield github.pullRequests.getAll({ owner: 'reactbkk', repo: '2.0.0' })
    for (const pull of pulls.data) {
      console.log(pull.number)
      yield * checkPullRequest(pull.number)
    }
  }

  function * checkClosedPullRequests () {
    const log = (text) => console.log(`[checkClosedPullRequests] ${text}`)
    log('Loading data...')
    const response = yield gh4.post('/graphql', {
      query: `query {
        repository (owner: "reactbkk", name: "2.0.0") {
          applicationPendingPullRequests: pullRequests (
            last: 50,
            states: [MERGED],
            labels: ["ticketing/application-pending"]
          ) {
            nodes {
      				number
              title
              body
              author { login }
              comments (last: 10) {
                nodes {
                  author { login }
                  body
                }
              }
            }
          }
        }
      }`
    })
    for (const pendingPr of response.data
      .data
      .repository
      .applicationPendingPullRequests
      .nodes
    ) {
      yield * checkPendingPR(pendingPr)
    }
    // console.log(JSON.stringify(response.data, null, 2))
  }

  function createPoster (number) {
    const outbox = [ ]
    return {
      say (text) {
        outbox.push(text)
      },
      post () {
        if (outbox.length) {
          const body = outbox.join('\n')
          return github.issues.createComment({ owner, repo, number, body })
        }
        return Promise.resolve()
      }
    }
  }

  function * checkPullRequest (number) {
    const log = (text) => console.log(`[${number}] ${text}`)

    log('Fetching pull request data')
    const pull = yield github.pullRequests.get({ owner, repo, number })
    const labels = yield github.issues.getIssueLabels({ owner, repo, number })
    const statuses = yield github.repos.getStatuses({ owner, repo, ref: pull.data.head.sha })
    const poster = createPoster(number)
    const hasLabel = (name) => labels.data.filter(x => String(x.name) === String(name)).length > 0
    const reply = (text) => poster.say(`@${pull.data.user.login} ${text}`)
    const addLabel = (name) => {
      return github.issues.addLabels({ owner, repo, number, labels: [ name ] })
    }
    const removeLabel = (name) => {
      return github.issues.removeLabel({ owner, repo, number, name })
    }
    const mergePullRequest = () => {
      return github.pullRequests.merge({ owner, repo, number })
    }

    try {
      if (containsIssueTag(pull.data.body)) {
        log('Issue tag OK')
        if (hasLabel(ISSUE_TAG_MISSING)) {
          log('Remove label')
          yield removeLabel(ISSUE_TAG_MISSING)
          reply('I found an issue tag now, thank you.')
        }
      } else {
        log('No issue tag')
        if (!hasLabel(ISSUE_TAG_MISSING)) {
          log('Add label')
          yield addLabel(ISSUE_TAG_MISSING)
          reply([
            'Please **update the pull request description** (not the title) to include an issue tag:',
            '',
            '- If this pull request solves an issue, say `Close #xx` where `xx` is the issue number.',
            '- If this pull request not associated with any issue, say `No associated issue`.',
            '',
            'Thank you. I will confirm with you again once the problem is fixed.'
          ].join('\n'))
        }
      }
      if (hasLabel(READY_TO_MERGE)) {
        log('PR ready to merge')
        yield removeLabel(READY_TO_MERGE)
        yield mergePullRequest()
        log('Just merged')
        yield addLabel(TICKET_APPLICATION_PENDING)
        reply([
          'Congratulations! Your PR has been merged. Please follow these steps to get your ticket.',
          '',
          '1. Fill in this [form](https://www.eventpop.me/events/1809-react-bangkok-2-0-0/application_forms/109/applicants/new?token=VV8VYR4HCNLNYNDU).',
          '2. Post a comment with your reference code in this pull request. (e.g. `#XXXXXXXX`)',
          '3. Wait for invitation email from Event Pop and follow the instruction from the email.',
          '',
          'Thank you for your contribution. See you in the event!'
        ].join('\n'))
      }
      const status = getCIStatus(statuses)
      if (status.state === 'success') {
        log('State success')
        if (hasLabel(BUILD_FAILED)) {
          log('Remove label')
          yield removeLabel(BUILD_FAILED)
          reply('CI build passed now. Thank you!')
        }
      } else if (status.state === 'failure' || status.state === 'error') {
        log('State ' + status.state)
        if (!hasLabel(BUILD_FAILED)) {
          log('Add label')
          yield addLabel(BUILD_FAILED)
          reply([
            'Sorry, the CI build failed. We cannot merge your pull request if CI build is not passing.',
            '',
            `Please [check the CI build log](${status.target_url}) for more information.`
          ].join('\n'))
        }
      }
    } finally {
      yield poster.post()
    }
  }

  function * checkPendingPR (pendingPr) {
    const number = pendingPr.number
    const log = (text) => console.log(`[${number}] ${text}`)
    const poster = createPoster(number)
    const reply = (text) => poster.say(`@${pull.data.user.login} ${text}`)
    const addLabel = (name) => {
      return github.issues.addLabels({ owner, repo, number, labels: [ name ] })
    }
    const removeLabel = (name) => {
      return github.issues.removeLabel({ owner, repo, number, name })
    }
    try {
      const userText = [
        pendingPr.body,
      ].concat(
        pendingPr.comments.nodes
          .filter(comment => comment.author.login === pendingPr.author.login)
          .map(comment => comment.body)
      ).join('\n')
      const match = userText.match(/#([A-Z0-9]{8})/)
      if (match) {
        const applicationNumber = match[1]
        log('Ticket code found')
        yield removeLabel(TICKET_APPLICATION_PENDING)
        yield addLabel(TICKET_ISSUE_PENDING)
        const newTitle = `[Application #${applicationNumber}] ${pendingPr.title}`
        yield github.pullRequests.update({ owner, repo, number, title: newTitle })
        reply([
          'Your Event Pop application number have been received.',
          '',
          `@PanJ Please approve application #${applicationNumber}.`
        ].join('\n'))
      } else {
        log('Ticket code still not found')
      }
    } finally {
      yield poster.post()
    }
  }

  function containsIssueTag (text) {
    return /(close|improve)(s)?\s*#\d+|no( associated)? issue/i.test(text)
  }

  function getEventPopApplication (text) {
    const match = text.match(/application ?#([a-z0-9]{8})/i);
    if (!match) return false;
    return match[1];
  }

  function getCIStatus (statuses) {
    const found = statuses.data.filter(s => s.context === 'ci/circleci')[0]
    if (!found) return { state: 'pending' }
    return found
  }

  main().then(x => cb(null, x), e => cb(e))
}