Nice way to add errors to Bacon EventStream?

Question

I've tried to find a good solution for adding errors to an bacon.js EventStream - and propagating them. All this because I wan't to handle the errors later possibly at multiple clients. I've found a hack with flatMap but it's a ... hack:

var streamWithPossibleProblems = bus.flatMap(function(v) {
    if (v == "problem") {
        return Bacon.sequentially(0, [new Bacon.Error("Error to be reported later")])
    }
    return v
});

I thought (mistakenly) that I need to return an EventStream here but it's enough to return a raw Bacon.Error it seems. — flash42, Nov 17 '14 at 22:16
Oh, that would be totally reasonable. But I wondered why you used `sequentially`, and sent a `0`? Just do `return Bacon.once(new Bacon.Error("fail"))`. — Bergi, Nov 17 '14 at 22:23

score 2 · Accepted Answer · edited Nov 17 '14 at 22:25

2

You can just return the Bacon.Error directly from flatMap:

var streamWithPossibleProblems = bus.flatMap(function(v) {
    if (v == "problem") {
        return new Bacon.Error("Error to be reported later")
    }
    return v
});

edited Nov 17 '14 at 22:25

Bergi

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answered Nov 17 '14 at 14:46

OlliM

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It really is better and also mentioned in the bacon.js readme - this must be the canonical answer then. – flash42 Nov 17 '14 at 22:13

Nice way to add errors to Bacon EventStream?

1 Answers1