Bluebird Spread (chaining successful promises)

1const Promise = require('bluebird');
2const mongoose = require('mongoose');
3mongoose.Promise = Promise;
4
5// Service
6function Service() {};
7service = new Service();
8// share the function for other instances of service
9// post-instatiation update of function logic
10Service.prototype.asyncOp = function(body) {
11  return new Promise(function(resolve, reject) {
12    setTimeout(() => resolve({'id':'sample'}), 1000); //
13  })
14}
15
16// Function Flow
17function ops(body) {
18  service.asyncOp(body)
19    .then(function provision(operation) {
20      const samples = db.getData({ q: 'samples' });
21      const telemetry = db.getData({ q: 'telemetry' });
22      const service = db.updateService({ q: 'dates', body: operation });
23      return [samples, telemetry, service];
24    })
25    .spread(function updateCache(samples, telemetry, service) {
26      cache.storeData(samples);
27      cache.storeData(telemetry);
28      const notification = ws.prepareNotification(service);
29      return notification;
30    })
31    // Jumper function - does not interfere with bluebird's spread chain
32    .spread(function sendNotificationToClient(notification) {
33      ws.notify(notification);
34    })
35    // Jumper function - does not interfere with bluebird's spread chain
36    .spread(function log(notification) {
37      logger.log(notification);
38    })
39    // End of chain
40    .then(function finalizeRequest(result) {
41      res.send(200);
42    })
43    .catch(function handleError(err) {
44      logger.log(err, 'Error while processing the transaction');
45      res.send({
46        code: err.code,
47        message: err.message,
48        metadata: err.metadata
49      });
50    });
51}
52
53// Caller
54ops();
55