Bacon.onEnd is not a function

Question

When my system is creating errors, those are collected and finally sent to a ticket API. All errors are grouped by their type of priority. So, if two different error types are thrown, two tickets should be sent.

Looks like:

var tickets = [{ 
    type: 'validation',
    component: 1,
    time: '2016-04-13T10:26:41.420Z',
    messages: [ [Object], [Object], [...] ]
}, { 
    type: 'fatal',
    component: 1,
    time: '2016-04-13T10:26:41.420Z',
    messages: [ [Object] ]
}];

Every object within that array should be sent after another, delayed by 2 seconds. sendToTicketAPI() returns a Promise and I also want to return a promise when all tickets are sent. My thought was, I could resolve/reject it with .onEnd/.onError.

Code is:

var Bacon = require('baconjs'); //v0.7.71

createTicketWrapper(msg, fnResolve, fnReject) {
    Bacon
    .fromArray(tickets)
    .bufferingThrottle(2000)
    .flatMap(function (ticket) {
        return sendToTicketAPI(ticket)
        .then(function () {
            return ticket;
        });
    })
    .onError(function (err) {
        console.error('Unexpected error msg', err);
        if (fnReject)
            fnReject();
    })
    .onEnd(function () {
        if (fnResolve)
            fnResolve()
    });
}

But I'm getting:

[TypeError: Bacon.fromArray(...).bufferingThrottle(...).flatMap(...).onError(...).onEnd is not a function]

I don't understand why .onEnd is not a function!? Maybe another approach?

Answer 1

onError returns a unsubscribe function(which does not have an onEnd function: "Just like subscribe, this method returns a function for unsubscribing." via https://baconjs.github.io/api.html#observable-onerror), not an eventstream(which does).

try this:

var Bacon = require('baconjs'); //v0.7.71

createTicketWrapper(msg, fnResolve, fnReject) {
    var stream = Bacon
    .fromArray(tickets)
    .bufferingThrottle(2000)
    .flatMap(function (ticket) {
        return sendToTicketAPI(ticket)
        .then(function () {
            return ticket;
        });
    });

    stream.onError(function (err) {
        console.error('Unexpected error msg', err);
        if (fnReject)
            fnReject();
    })
    stream.onEnd(function () {
        if (fnResolve)
            fnResolve()
    });
}

Note that I assigned the eventstream created from flatMap to a variable, and then used that to subscribe to onError and onEnd seperately.