merginator.js

const axios = require('axios');
const { from, interval, combineLatest } = require('rxjs');
const { switchMap, pluck, flatMap, distinct, skipWhile, share } = require('rxjs/operators');
const baseURL = process.env.GITLAB_ENDPOINT || 'https://gitlab.com';
const privateToken = process.env.GITLAB_TOKEN;
const pollingInterval = 2000;
const UPVOTES = 2;

const client = axios.create({ baseURL, headers: { 'Private-Token': privateToken }});

function fetchMergeRequests() {
  return client.get('/api/v4/merge_requests?state=opened');
}

function getMergeRequest({project_id, iid}) {
  return client.get(`/api/v4/projects/${project_id}/merge_requests/${iid}`);
}

function merge({project_id, iid}) {
  return client.put(`/api/v4/projects/${project_id}/merge_requests/${iid}/merge`);
}

const myMergeRequests$ = interval(pollingInterval).pipe(
  switchMap(() => from(fetchMergeRequests())),
  pluck('data')
);

const newMergeRequest$ = myMergeRequests$.pipe(
  flatMap(mr => mr),
  distinct(mr => mr.id)
);

function mergeRequest$(mr) {
  return interval(pollingInterval).pipe(
    switchMap(() => from(getMergeRequest(mr))),
    pluck('data')
  );
}

function upvotes$(shareMergeRequest) {
  return shareMergeRequest.pipe(
    pluck('upvotes'),
    skipWhile(upvotes => upvotes < UPVOTES)
  );
}

function mergeStatus$(shareMergeRequest$) {
  return shareMergeRequest$.pipe(
    pluck('merge_status'),
    skipWhile(mergeStatus => mergeStatus !== 'can_be_merged')
  );
}

const newMergeRequestSubscription = newMergeRequest$.subscribe(mr => {
  console.log(new Date(), 'There is a new merge request', mr.title);

  const shareMergeRequest$ = mergeRequest$(mr).pipe(share());
  const merginatorSubscription$ = combineLatest(upvotes$(shareMergeRequest$), mergeStatus$(shareMergeRequest$)).subscribe(() => {
    console.log(`MERGINATOR is about to merge ${mr.title}`)
    merge(mr).then(() => {
      console.log('MERGINATOR 💪');
      merginatorSubscription$.unsubscribe();
    }).catch(err => {
      console.log('MERGINATOR should call Chuck Norris', err);
    })
  });
});

(function wait() {
  setTimeout(wait, 1000);
})();