Quick test for verifying that the "fast case" in EventEmitter.prototype.emit is warranted

quick-micro-optimization-test.js

// dummy func
function noop() {}

// optimized via if/else
function testIfElse() {
	var len = arguments.length;
	if (len === 1) {
		noop(arguments[0]);
	} else if (len === 2) {
		noop(arguments[1]);
	} else {
		noop.apply(null, Array.prototype.slice.call(arguments, 0));
	}
}

// optimized via switch
function testSwitch() {
	switch (arguments.length) {
		case 1:
			noop(arguments[0]);
			break;
		case 2:
			noop(arguments[1]);
			break;
		default:
			noop.apply(null, Array.prototype.slice.call(arguments, 0));
	}
}

// no optimizations
function testNeither() {
	noop.apply(null, Array.prototype.slice.call(arguments, 0));
}

// test cases
var tests = [
	[testIfElse, ['test']],
	[testIfElse, ['test', 'test']],
	[testIfElse, ['test', 'test', 'test']],
	[testSwitch, ['test']],
	[testSwitch, ['test', 'test']],
	[testSwitch, ['test', 'test', 'test']],
	[testNeither, ['test']],
	[testNeither, ['test', 'test']],
	[testNeither, ['test', 'test', 'test']]
];

console.log('Running tests...\n');

// run tests
tests.forEach(function(test) {
	var func = test[0],
		args = test[1];
	console.log(func.name + '(', args, ');');

	var i = 0, start = Date.now();

	for (; i < 5000000; i++) {
		func.apply(null, args);
	}

	console.log(Date.now() - start + '\n');
});