A monkey patch which will override a method and throw an error after method is run a specific number of times

monkeypatch

exports.forceWreckError = function (method, timer) {

    var original = Wreck[method];

    Wreck[method] = function () {

        if (!timer) {
            var callback = arguments[arguments.length - 1];
            Wreck[method] = original;
            return callback(new Error('foo'));
        }

        --timer;
        return original.apply(Wreck, arguments);
    };
};