an event-based approach to github.com/bpedro/node-expectation

expectations.js

exports.create = function(checkFunction, data, period) {
	var emitter = new (require("events").EventEmitter)();
	var wrapper = function(data) {
		if (result = checkFunction(data))
			emitter.emit("checked", result);
		else
			setTimeout(emitter.start, period || 1000);
	};
	
	emitter.start = function () { emitter.emit("start"); };
	emitter.on("start", function() { wrapper(data); });
		
	return emitter;
};