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This very simple example shows usage of CommonJS.

The three files example.js, increment.js and math.js form a dependency chain. They use require(dependency) to declare dependencies.

You can see the output file that webpack creates by bundling them together in one file. Keep in mind that webpack adds comments to make reading this file easier. These comments are removed when minimizing the file.

You can also see the info messages webpack prints to console (for both normal and minimized build).

example.js

var inc = require('./increment').increment;
var a = 1;
inc(a); // 2

increment.js

var add = require('./math').add;
exports.increment = function(val) {
    return add(val, 1);
};

math.js

exports.add = function() {
    var sum = 0, i = 0, args = arguments, l = args.length;
    while (i < l) {
        sum += args[i++];
    }
    return sum;
};

dist/output.js

/******/ (function(modules) { /* webpackBootstrap */ })

/******/ (function(modules) { // webpackBootstrap
/******/ 	// The module cache
/******/ 	var installedModules = {};
/******/
/******/ 	// The require function
/******/ 	function __webpack_require__(moduleId) {
/******/
/******/ 		// Check if module is in cache
/******/ 		if(installedModules[moduleId]) {
/******/ 			return installedModules[moduleId].exports;
/******/ 		}
/******/ 		// Create a new module (and put it into the cache)
/******/ 		var module = installedModules[moduleId] = {
/******/ 			i: moduleId,
/******/ 			l: false,
/******/ 			exports: {}
/******/ 		};
/******/
/******/ 		// Execute the module function
/******/ 		modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);
/******/
/******/ 		// Flag the module as loaded
/******/ 		module.l = true;
/******/
/******/ 		// Return the exports of the module
/******/ 		return module.exports;
/******/ 	}
/******/
/******/
/******/ 	// expose the modules object (__webpack_modules__)
/******/ 	__webpack_require__.m = modules;
/******/
/******/ 	// expose the module cache
/******/ 	__webpack_require__.c = installedModules;
/******/
/******/ 	// define getter function for harmony exports
/******/ 	__webpack_require__.d = function(exports, name, getter) {
/******/ 		if(!__webpack_require__.o(exports, name)) {
/******/ 			Object.defineProperty(exports, name, {
/******/ 				configurable: false,
/******/ 				enumerable: true,
/******/ 				get: getter
/******/ 			});
/******/ 		}
/******/ 	};
/******/
/******/ 	// define __esModule on exports
/******/ 	__webpack_require__.r = function(exports) {
/******/ 		Object.defineProperty(exports, '__esModule', { value: true });
/******/ 	};
/******/
/******/ 	// getDefaultExport function for compatibility with non-harmony modules
/******/ 	__webpack_require__.n = function(module) {
/******/ 		var getter = module && module.__esModule ?
/******/ 			function getDefault() { return module['default']; } :
/******/ 			function getModuleExports() { return module; };
/******/ 		__webpack_require__.d(getter, 'a', getter);
/******/ 		return getter;
/******/ 	};
/******/
/******/ 	// Object.prototype.hasOwnProperty.call
/******/ 	__webpack_require__.o = function(object, property) { return Object.prototype.hasOwnProperty.call(object, property); };
/******/
/******/ 	// __webpack_public_path__
/******/ 	__webpack_require__.p = "dist/";
/******/
/******/
/******/ 	// Load entry module and return exports
/******/ 	return __webpack_require__(__webpack_require__.s = 0);
/******/ })
/************************************************************************/

/******/ ([
/* 0 */
/*!********************!*\
  !*** ./example.js ***!
  \********************/
/*! no static exports found */
/***/ (function(module, exports, __webpack_require__) {

var inc = __webpack_require__(/*! ./increment */ 1).increment;
var a = 1;
inc(a); // 2

/***/ }),
/* 1 */
/*!**********************!*\
  !*** ./increment.js ***!
  \**********************/
/*! no static exports found */
/***/ (function(module, exports, __webpack_require__) {

var add = __webpack_require__(/*! ./math */ 2).add;
exports.increment = function(val) {
    return add(val, 1);
};

/***/ }),
/* 2 */
/*!*****************!*\
  !*** ./math.js ***!
  \*****************/
/*! no static exports found */
/***/ (function(module, exports) {

exports.add = function() {
    var sum = 0, i = 0, args = arguments, l = args.length;
    while (i < l) {
        sum += args[i++];
    }
    return sum;
};

/***/ })
/******/ ]);

Info

Unoptimized

Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 4.0.0-beta.2
    Asset      Size  Chunks             Chunk Names
output.js  3.44 KiB       0  [emitted]  main
Entrypoint main = output.js
chunk    {0} output.js (main) 329 bytes [entry] [rendered]
    > .\example.js main
    [0] ./example.js 69 bytes {0} [built]
        single entry .\example.js  main
    [1] ./increment.js 98 bytes {0} [built]
        cjs require ./increment [0] ./example.js 1:10-32
    [2] ./math.js 162 bytes {0} [built]
        cjs require ./math [1] ./increment.js 1:10-27

Production mode

Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 4.0.0-beta.2
    Asset       Size  Chunks             Chunk Names
output.js  740 bytes       0  [emitted]  main
Entrypoint main = output.js
chunk    {0} output.js (main) 329 bytes [entry] [rendered]
    > .\example.js main
    [0] ./math.js 162 bytes {0} [built]
        cjs require ./math [1] ./increment.js 1:10-27
    [1] ./increment.js 98 bytes {0} [built]
        cjs require ./increment [2] ./example.js 1:10-32
    [2] ./example.js 69 bytes {0} [built]
        single entry .\example.js  main

5.6 KiB Raw Blame History