Exceptions/Errors are not caught/handled in any queue items beyond the first.

[EricByers]

Specifically in nodejs (v0.12.7). I'm using Q for promises, but I think the same will happen with others.

Some sample code:

var Q = require('q');
var Queue = require('promise-queue');
Queue.configure(function (handler) {
    var deferred = Q.defer();
    try {
        handler(deferred.resolve, deferred.reject, deferred.notify);
    } catch (e) {
        console.error(e);
        deferred.reject(e);
    }
    return deferred.promise;
});

var maxConcurrent = 1;
var maxQueue = Infinity;
var serialQueue = new Queue(maxConcurrent, maxQueue);

serialQueue.add(function() {
     throw new Error('error that is caught');
});

serialQueue.add(function() {
     throw new Error('error that is not caught');
});

My thought is that the first one works because the _dequeue is directly in the try/catch. However on subsequent calls when the _dequeue is called from the then/reject the scope changes and it's not in the try/catch block anymore.

I was going to take a stab at a PR, but not sure the best way of handling it or if it's even possible without changing the interface.

[azproduction]

Resolved in promise-queue@2.2.0