A LeanEngine function that sends a Slack notification when the given GitHub repo got starred.

slack-on-repo-starred.js

// parameters of the function
var repo = request.params.repo;  // 'user_or_org/repo_name'
var slackWebhook = request.params.slackWebhook;  // e.g. 'https://hooks.slack.com/services/XXX'

var repoUrl = 'https://api.github.com/repos/' + repo;

// Set the following names to match your own scheme
var className = 'RepoStars';  // LeanCloud class for storing repo stars
var fieldRepo = 'repo';  // LeanCloud field to store the repo name
var fieldStars = 'count';  // LeanCloud field to store the count of stars

var RepoStars = AV.Object.extend(className);

var postToSlack = function (newStars, total) {
  console.log('posting to slack, new stars is:', newStars);

  var msg = newStars > 0 ? ':clap:' + repo + ' got another ' + newStars +
        ' stars, to a total of ' + total + '!:+1::metal::tada:'
    : ':broken_heart:' + repo + ' lost ' + (-newStars) + ' stars, to a total of ' + total +
        '!:sob: work harder to win them back!:facepunch:';

  return AV.Cloud.httpRequest({
      method: 'POST',
      url: slackWebhook,
      headers: {
        'Content-Type': 'application/json'
      },
      body: {
        text: msg
      }
    });
};

var onRepoStarred = function (resp) {
  var count = resp.data.stargazers_count;
  var theRepoStars;

  console.log('latest stars is:', count);
  return new AV.Query(RepoStars)
    .equalTo(fieldRepo, repo)
    .first()
    .then(function (repoStars) {
      theRepoStars = repoStars;
      return repoStars ? repoStars.get(fieldStars) : 0;
    })
    .then(function (prevCount) {
      console.log('previous stars:', prevCount);
      if (count !== prevCount) {
        // got starred or unstarred, notify through Slack WebHook
        return postToSlack(count - prevCount, count);
      }
    })
    .then(function (starsChanged) {
      if (!starsChanged) {
        // stars not changed, don't waste api quota
        return;
      }

      // save the latest star count
      if (!theRepoStars) {
        theRepoStars = new RepoStars();
        theRepoStars.set(fieldRepo, repo);
      }

      theRepoStars.set(fieldStars, count);
      return theRepoStars.save();
    });
};

AV.Cloud.httpRequest({
    url: repoUrl,
    headers: {
      'Cache-Control': 'no-cache',
      'User-Agent': 'repo-stars-poller'
    }
  })
  .then(onRepoStarred)
  .then(function () {
    response.success();
  })
  .catch(function (err) {
    response.error(err);
  });

LeanCloud

• https://leancloud.cn for users from China
• https://avoscloud.us for those from U.S.

Starred

Unstarred