wooandoo/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<title>conditionally adding entries inside Array and object literals</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
</head>
<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
</body>
</html>

## suite.js
"use strict";

(function (factory) {
	if (typeof Benchmark !== "undefined") {
		factory(Benchmark);
	} else {
		factory(require("benchmark"));
	}
})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
		const cond = false;

		function insertIf(condition, ...elements) { // (A)
		    return condition ? elements : [];
		}

		function insertIntoIf(condition, array, element) { // (A)
		    condition
		    && array.push(element)
		}
	};


	suite.add("const arr = [", function () {
		const arr = [
		  ...(cond ? ['a'] : []),
		  'b',
		];
	});

	suite.add("const arr = [];", function () {
		const arr = [];
		if (cond) {
		    arr.push('a');
		}
		arr.push('b');
	});

	suite.add("const arr = [", function () {
		const arr = [
		  ...insertIf(cond, 'a'),
		  'b',
		];
	});

	suite.add("const arr = [];", function () {
		const arr = [];
		insertIntoIf(cond, arr, 'a')
		insertIntoIf(true, arr, 'a')
	});

	suite.on("cycle", function (evt) {
		console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
		console.log(new Array(30).join("-"));

		var results = evt.currentTarget.sort(function (a, b) {
			return b.hz - a.hz;
		});

		results.forEach(function (item) {
			console.log((idx + 1) + ". " + item);
		});
	});

	console.log("conditionally adding entries inside Array and object literals");
	console.log(new Array(30).join("-"));
	suite.run();
});
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<title>conditionally adding entries inside Array and object literals</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
	</head>
	<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
	</body>
	</html>
	"use strict";

	(function (factory) {
	if (typeof Benchmark !== "undefined") {
	factory(Benchmark);
	} else {
	factory(require("benchmark"));
	}
	})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
	const cond = false;

	function insertIf(condition, ...elements) { // (A)
	return condition ? elements : [];
	}

	function insertIntoIf(condition, array, element) { // (A)
	condition
	&& array.push(element)
	}
	};


	suite.add("const arr = [", function () {
	const arr = [
	...(cond ? ['a'] : []),
	'b',
	];
	});

	suite.add("const arr = [];", function () {
	const arr = [];
	if (cond) {
	arr.push('a');
	}
	arr.push('b');
	});

	suite.add("const arr = [", function () {
	const arr = [
	...insertIf(cond, 'a'),
	'b',
	];
	});

	suite.add("const arr = [];", function () {
	const arr = [];
	insertIntoIf(cond, arr, 'a')
	insertIntoIf(true, arr, 'a')
	});

	suite.on("cycle", function (evt) {
	console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
	console.log(new Array(30).join("-"));

	var results = evt.currentTarget.sort(function (a, b) {
	return b.hz - a.hz;
	});

	results.forEach(function (item) {
	console.log((idx + 1) + ". " + item);
	});
	});

	console.log("conditionally adding entries inside Array and object literals");
	console.log(new Array(30).join("-"));
	suite.run();
	});