webpack 1 working behavior

.gitignore

node_modules/

README.md

npm install
npm run build
npm run serve

a-out.js

console.log('a-out.js executed');
webpackJsonp([0],[
/* 0 */
/***/ function(module, exports, __webpack_require__) {

	const share = __webpack_require__(1);
	share();
	console.log('a init');

/***/ }
]);

b-out.js

console.log('b-out.js executed');
webpackJsonp([1],[
/* 0 */
/***/ function(module, exports, __webpack_require__) {

	const share = __webpack_require__(1);
	share();
	console.log('b init');

/***/ }
]);

commons.js

console.log('commons.js executed');
/******/ (function(modules) { // webpackBootstrap
/******/ 	// install a JSONP callback for chunk loading
/******/ 	var parentJsonpFunction = window["webpackJsonp"];
/******/ 	window["webpackJsonp"] = function webpackJsonpCallback(chunkIds, moreModules) {
/******/ 		// add "moreModules" to the modules object,
/******/ 		// then flag all "chunkIds" as loaded and fire callback
/******/ 		var moduleId, chunkId, i = 0, callbacks = [];
/******/ 		for(;i < chunkIds.length; i++) {
/******/ 			chunkId = chunkIds[i];
/******/ 			if(installedChunks[chunkId])
/******/ 				callbacks.push.apply(callbacks, installedChunks[chunkId]);
/******/ 			installedChunks[chunkId] = 0;
/******/ 		}
/******/ 		for(moduleId in moreModules) {
/******/ 			modules[moduleId] = moreModules[moduleId];
/******/ 		}
/******/ 		if(parentJsonpFunction) parentJsonpFunction(chunkIds, moreModules);
/******/ 		while(callbacks.length)
/******/ 			callbacks.shift().call(null, __webpack_require__);
/******/ 		if(moreModules[0]) {
/******/ 			installedModules[0] = 0;
/******/ 			return __webpack_require__(0);
/******/ 		}
/******/ 	};

/******/ 	// The module cache
/******/ 	var installedModules = {};

/******/ 	// object to store loaded and loading chunks
/******/ 	// "0" means "already loaded"
/******/ 	// Array means "loading", array contains callbacks
/******/ 	var installedChunks = {
/******/ 		2:0
/******/ 	};

/******/ 	// 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] = {
/******/ 			exports: {},
/******/ 			id: moduleId,
/******/ 			loaded: false
/******/ 		};

/******/ 		// Execute the module function
/******/ 		modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);

/******/ 		// Flag the module as loaded
/******/ 		module.loaded = true;

/******/ 		// Return the exports of the module
/******/ 		return module.exports;
/******/ 	}

/******/ 	// This file contains only the entry chunk.
/******/ 	// The chunk loading function for additional chunks
/******/ 	__webpack_require__.e = function requireEnsure(chunkId, callback) {
/******/ 		// "0" is the signal for "already loaded"
/******/ 		if(installedChunks[chunkId] === 0)
/******/ 			return callback.call(null, __webpack_require__);

/******/ 		// an array means "currently loading".
/******/ 		if(installedChunks[chunkId] !== undefined) {
/******/ 			installedChunks[chunkId].push(callback);
/******/ 		} else {
/******/ 			// start chunk loading
/******/ 			installedChunks[chunkId] = [callback];
/******/ 			var head = document.getElementsByTagName('head')[0];
/******/ 			var script = document.createElement('script');
/******/ 			script.type = 'text/javascript';
/******/ 			script.charset = 'utf-8';
/******/ 			script.async = true;

/******/ 			script.src = __webpack_require__.p + "" + chunkId + "." + ({"0":"a","1":"b"}[chunkId]||chunkId) + "-out.js";
/******/ 			head.appendChild(script);
/******/ 		}
/******/ 	};

/******/ 	// expose the modules object (__webpack_modules__)
/******/ 	__webpack_require__.m = modules;

/******/ 	// expose the module cache
/******/ 	__webpack_require__.c = installedModules;

/******/ 	// __webpack_public_path__
/******/ 	__webpack_require__.p = "";
/******/ })
/************************************************************************/
/******/ ([
/* 0 */,
/* 1 */
/***/ function(module, exports) {

	function share() {
	    return 1;
	}
	module.exports = share;

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

entry-a.js

const share = require('./shared');
share();
console.log('a init');

entry-b.js

const share = require('./shared');
share();
console.log('b init');

index.html

<html lang="en">
    <head>
        <meta http-equiv="content-type" content="text/html; charset=utf-8">
        <title>Demo</title>
    </head>
    <body>
        <h1>Demo</h1>
        <script>
        function insertScript(url) {
            var script = document.createElement('script');
            script.type = 'text/javascript';
            script.src = url;
            document.head.appendChild(script);
        }
        function loadA() {
            loadCommons();
            insertScript('/a-out.js');
        }
        function loadB() {
            loadCommons();
            insertScript('/b-out.js');
        }
        var isCommonsLoaded;
        function loadCommons() {
            if (isCommonsLoaded) {
                return;
            }
            insertScript('/commons.js');
            isCommonsLoaded = true;
        }
        </script>
        <button onClick="loadA()">Load A</button>
        <button onClick="loadB()">Load B</button>
        <p>
            Check out the console. Each time the buttons are clicked, another script tag gets added.
            This runs the code inside the script. As entry modules, each time A or B are loaded,
            they entry modules do re-run, and log their init.
        </p>
    </body>
</html>

package.json

{
  "name": "webpack2-execute-modules-bug",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack",
    "serve": "http-server"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "http-server": "^0.9.0",
    "webpack": "^1.14.0",
    "webpack-sources": "^0.2.3"
  }
}

shared.js

function share() {
    return 1;
}
module.exports = share;

webpack.config.js

const webpack = require('webpack');
const ConcatSource = require("webpack-sources").ConcatSource;
// Make each file console.log its own name when executed
class NameAnnouncerPlugin {
    apply(compiler) {
		compiler.plugin("compilation", (compilation) => {
			compilation.plugin("optimize-chunk-assets", (chunks, callback) => {
				chunks.forEach((chunk) => {
					chunk.files
						.forEach((file) =>
							compilation.assets[file] = new ConcatSource(
								`console.log('${file} executed');`, "\n", compilation.assets[file]
							)
						);
				});
				callback();
			});
		});        
    }
}

module.exports = {
    output: {
        filename: "[name]-out.js"
    },
    entry: {
        a: './entry-a.js',
        b: './entry-b.js'
    },
    plugins: [
        new webpack.optimize.CommonsChunkPlugin({ 
            name: 'commons',
            filename: 'commons.js',
            chunks: ['a', 'b']
        }),
        new NameAnnouncerPlugin()
    ]
};