-

var Rx = require('rx');

var s1 = new Rx.Subject();
var s2 = new Rx.Subject();
var s3 = new Rx.Subject();

Rx.Observable.merge(s1, s2, s3).
    forEach(
        console.log.bind(console, 'next'),
        console.log.bind(console, 'error'),
        console.log.bind(console, 'complete')
    );

s1.onNext(1);
s2.onCompleted(1);
s3.onCompleted(1);
s1.onCompleted(1);