Benchmark: Object Composition vs Instantiation

Script Preparation code:

(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
"use strict";

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var barker = function barker(state) {
    return {
        bark: function bark() {
            return console.log("woof, I am " + state.name);
        }
    };
};

var driver = function driver(state) {
    return {
        drive: function drive() {
            return state.position = state.position + state.speed;
        }
    };
};

var robotDog = function robotDog(name) {
    var state = {
        name: name,
        speed: 100,
        position: 0
    };
    return Object.assign({}, barker(state), driver(state));
};

var Driver = function () {
    function Driver() {
        _classCallCheck(this, Driver);
    }

    _createClass(Driver, [{
        key: "drive",
        value: function drive() {
            console.log("I am driving");
        }
    }]);

    return Driver;
}();

var Barker = function (_Driver) {
    _inherits(Barker, _Driver);

    function Barker(name) {
        _classCallCheck(this, Barker);

        var _this = _possibleConstructorReturn(this, (Barker.__proto__ || Object.getPrototypeOf(Barker)).call(this));

        _this.name = name;
        return _this;
    }

    _createClass(Barker, [{
        key: "bark",
        value: function bark() {
            console.log("woof, I am " + this.name);
        }
    }]);

    return Barker;
}(Driver);

window.robotDog = robotDog;
window.Barker = Barker;
},{}]},{},[1])

Tests:

Instantiation
var red = new Barker("red");
Composition
var yellow = robotDog("yellow");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Instantiation
Composition

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'll do my best to explain what's being tested in this benchmark.

The provided JSON represents a JavaScript microbenchmarking test, specifically testing the performance difference between two approaches: object composition and instantiation.

**Benchmark Definition**

The test consists of two individual test cases:

1. **Instantiation**: This test case creates an instance of the `Barker` class using the `new` keyword: `var red = new Barker("red");`. The benchmark is measuring how fast this code executes.
2. **Composition**: This test case creates an instance of the `robotDog` function, which returns an object with two properties: `bark` and `drive`: `var yellow = robotDog("yellow");`. The benchmark is measuring how fast this code executes.

**Benchmark Code**

The provided JavaScript code defines several functions:

*   `barker(state)`: Returns an object with a `bark` method that logs "woof, I am <state.name>" to the console.
*   `driver(state)`: Returns an object with a `drive` method that updates `state.position` by adding `state.speed`.
*   `robotDog(name)`: Returns an object with `bark` and `drive` methods after merging the results of `barker` and `driver` using `Object.assign`.

**Options Compared**

The two test cases compare two approaches:

1.  **Instantiation**: Creates a new instance of the `Barker` class.
2.  **Composition**: Creates an instance of the `robotDog` function, which returns an object.

**Pros and Cons**

*   **Instantiation**: Pros:
    *   Easier to understand and maintain.
    *   More explicit creation of objects.
    Cons:
    *   May incur overhead due to dynamic property lookup and prototype chain traversal.
*   **Composition**: Pros:
    *   Can lead to more efficient code, as properties are directly attached to the object's prototype.
    Cons:
    *   Requires a deeper understanding of JavaScript object models.

**Library**

The `Object.assign()` method is used in the benchmark code. This method is a part of the ECMAScript standard and allows copying values from an existing object into a new object.

**Special JS Features or Syntax**

This benchmark uses modern JavaScript features, such as:

*   **Arrow functions**: Used for creating small, anonymous functions.
*   **Template literals**: Used for string interpolation.
*   **Spread syntax**: Used to merge objects and arrays.

These features are widely supported in modern browsers and can improve code readability and maintainability.

**Alternatives**

Other alternatives for composition include:

*   Using constructors like `Barker` to create instances.
*   Utilizing classes and the `this` keyword to define properties and methods.

However, the composition approach used in this benchmark is a common pattern in JavaScript programming.

Related benchmarks:

Object Composition vs Instantiation (version: 0)

Comparing performance of: Instantiation vs Composition

Created: 9 years ago by: Guest

Jump to the latest result

Instantiation

Composition

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):