Trying and failing to emulate EventTarget error handling with JS

event-emitter.js

function EventEmitter() {
    this._eventsMap = Object.create(null);
}

EventEmitter.prototype.on = function (eventName, handler) {
    if (!this._eventsMap[eventName]) {
        this._eventsMap[eventName] = [];
    }

    this._eventsMap[eventName].push(handler);
};

EventEmitter.prototype.off = function (eventName, handler) {
    var handlers = this._eventsMap[eventName];
    if (!handlers) {
        return;
    }

    var index = handlers.indexOf(handler);
    if (index === -1) {
        return;
    }

    handlers.splice(index, -1);
};

EventEmitter.prototype.emit = function (eventName) {
    var handlers = this._eventsMap[eventName];
    if (!handlers) {
        return;
    }

    var args = Array.prototype.slice.call(arguments, 1);

    executeHandler(0);

    function executeHandler(index) {
        if (index >= handlers.length) {
            return;
        }

        try {
            handlers[index].apply(undefined, args);
        } finally {
            executeHandler(index + 1);
        }
    }
};

var ee = new EventEmitter();
ee.on("foo", function (x) {
    console.log("my EE handler #1: ", x);
});
ee.on("foo", function (x) {
    console.log("my EE handler #2: ", x);
    throw new Error("boo!");
    console.log("should never get here");
});
ee.on("foo", function (x) {
    console.log("my EE handler #3: ", x);
});

ee.emit("foo", "arg");

// result: my EE handler #1, my EE handler #2, my EE handler #3, boo!

////

window.addEventListener("foo", function (x) {
    console.log("EventTarget handler #1: ", x);
});
window.addEventListener("foo", function (x) {
    console.log("EventTarget handler #2: ", x);
    throw new Error("boo!");
    console.log("should never get here");
});
window.addEventListener("foo", function (x) {
    console.log("EventTarget handler #3: ", x);
});

window.dispatchEvent(new CustomEvent("foo", { detail: "arg" }));

// result: EventTarget handler #1, EventTarget handler #2, boo!, EventTarget handler #3