BaconJS combineTemplate vs HighlandJS zip vs Bluebird join vs BaconJS zip vs Kefir zip

bacon.combineTemplate.js

const restify = require('restify');
const server = restify.createServer();

const Bacon = require('baconjs');

server.get('/', function(req, res, next) {

  const a = Bacon.once('a');
  const b = Bacon.once('b');

  a.flatMap(a => Bacon.combineTemplate({a, b}))
   .onValue(template => {
      res.send(template);
      next();
      return Bacon.noMore; //unsubscribe onValue
    });
});

server.listen(3000, function() {
  console.log('Listening on port 3000');
});

bacon.zip.js

const restify = require('restify');
const server = restify.createServer();

const Bacon = require('baconjs');

server.get('/', function(req, res, next) {

  const a = Bacon.once('a');
  const b = Bacon.once('b');

  a.zip(b, (a,b) => { return [a, b]; })
   .onValue(template => {
      res.send(template);
      next();
      return Bacon.noMore; //unsubscribe onValue
    });
});

server.listen(3000, function() {
  console.log('Listening on port 3000');
});

bluebird.js

const restify = require('restify');
const server = restify.createServer();

const Promise = require('bluebird');

server.get('/', function(req, res, next) {

  const a = new Promise((res,err) => res('a'));
  const b = new Promise((res,err) => res('b'));

  a.then(a => Promise.join(a, b))
    .then(template => {
      res.send(template);
      next();
    });
});

server.listen(3000, function() {
  console.log('Listening on port 3000');
});

highland.js

const restify = require('restify');
const server = restify.createServer();

const h = require('highland');

server.get('/', function(req, res, next) {

  const a = h(['a']);
  const b = h(['b']);

  a.zip(b)
    .pull((err, template) => {
      res.send(template);
      next();
    });
});

server.listen(3000, function() {
  console.log('Listening on port 3000');
});

kefir.zip.js

const Kefir = require('kefir');

const restify = require('restify');
const server = restify.createServer();

server.get('/', function(req, res, next) {

  const a = Kefir.fromCallback(callback => callback('a'));
  const b = Kefir.fromCallback(callback => callback('b'));
  
  a.zip(b).onValue(template => {
    res.send(template);
    next();
  });
});

server.listen(3000, function() {
  console.log('Listening on port 3000');
});