webpack/examples/chunkhash/README.md

14 KiB

A common challenge with combining [chunkhash] and Code Splitting is that the entry chunk includes the webpack runtime and with it the chunkhash mappings. This means it's always updated and the [chunkhash] is pretty useless, because this chunk won't be cached.

A very simple solution to this problem is to create another chunk which contains only the webpack runtime (including chunkhash map). This can be achieved with the optimization.runtimeChunk options. To avoid the additional request for another chunk, this pretty small chunk can be inlined into the HTML page.

The configuration required for this is:

  • use [chunkhash] in output.filename (Note that this example doesn't do this because of the example generator infrastructure, but you should)
  • use [chunkhash] in output.chunkFilename (Note that this example doesn't do this because of the example generator infrastructure, but you should)

example.js

// some module
import("./async1");
import("./async2");

webpack.config.js

var path = require("path");
module.exports = {
	// mode: "development || "production",
	entry: {
		main: "./example"
	},
	optimization: {
		runtimeChunk: true
	},
	output: {
		path: path.join(__dirname, "dist"),
		filename: "[name].[chunkhash].js",
		chunkFilename: "[name].[chunkhash].js"
	}
};

index.html

<html>
<head>
</head>
<body>

<!-- inlined minimized file "runtime~main.[chunkhash].js" -->
<script>
!function(e){function r(r){for(var n,o,i=r[0],c=r[1],s=r[2],p=0,f=[];p<i.length;p++)o=i[p],u[o]&&f.push(u[o][0]),u[o]=0;for(n in c)Object.prototype.hasOwnProperty.call(c,n)&&(e[n]=c[n]);for(l&&l(r);f.length;)f.shift()();return a.push.apply(a,s||[]),t()}function t(){for(var e,r=0;r<a.length;r++){for(var t=a[r],o=!0,i=1;i<t.length;i++){var c=t[i];0!==u[c]&&(o=!1)}o&&(a.splice(r--,1),e=n(n.s=t[0]))}return e}function n(r){if(o[r])return o[r].exports;var t=o[r]={i:r,l:!1,exports:{}};return e[r].call(t.exports,t,t.exports,n),t.l=!0,t.exports}var o={},u={2:0},a=[];n.e=function(e){var r=[],t=u[e];if(0!==t)if(t)r.push(t[2]);else{var o=new Promise(function(r,n){t=u[e]=[r,n]});r.push(t[2]=o);var a=document.getElementsByTagName("head")[0],i=document.createElement("script");i.charset="utf-8",i.timeout=12e4,n.nc&&i.setAttribute("nonce",n.nc),i.src=n.p+""+({}[e]||e)+".[chunkhash].js";var c=setTimeout(function(){s({type:"timeout",target:i})},12e4);i.onerror=i.onload=s;function s(r){i.onerror=i.onload=null,clearTimeout(c);var t=u[e];if(0!==t){if(t){var n=r&&("load"===r.type?"missing":r.type),o=r&&r.target&&r.target.src,a=new Error("Loading chunk "+e+" failed.\n("+n+": "+o+")");a.type=n,a.request=o,t[1](a)}u[e]=void 0}}a.appendChild(i)}return Promise.all(r)},n.m=e,n.c=o,n.d=function(e,r,t){n.o(e,r)||Object.defineProperty(e,r,{configurable:!1,enumerable:!0,get:t})},n.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},n.n=function(e){var r=e&&e.__esModule?function(){return e.default}:function(){return e};return n.d(r,"a",r),r},n.o=function(e,r){return Object.prototype.hasOwnProperty.call(e,r)},n.p="dist/",n.oe=function(e){throw console.error(e),e};var i=window.webpackJsonp=window.webpackJsonp||[],c=i.push.bind(i);i.push=r,i=i.slice();for(var s=0;s<i.length;s++)r(i[s]);var l=c;t()}([]);
</script>

<script src="dist/main.[chunkhash].js"></script>

</body>
</html>

dist/runtime~main.[chunkhash].js

/******/ (function(modules) { /* webpackBootstrap */ })
/******/ (function(modules) { // webpackBootstrap
/******/ 	// install a JSONP callback for chunk loading
/******/ 	function webpackJsonpCallback(data) {
/******/ 		var chunkIds = data[0];
/******/ 		var moreModules = data[1]
/******/ 		var executeModules = data[2];
/******/ 		// add "moreModules" to the modules object,
/******/ 		// then flag all "chunkIds" as loaded and fire callback
/******/ 		var moduleId, chunkId, i = 0, resolves = [];
/******/ 		for(;i < chunkIds.length; i++) {
/******/ 			chunkId = chunkIds[i];
/******/ 			if(installedChunks[chunkId]) {
/******/ 				resolves.push(installedChunks[chunkId][0]);
/******/ 			}
/******/ 			installedChunks[chunkId] = 0;
/******/ 		}
/******/ 		for(moduleId in moreModules) {
/******/ 			if(Object.prototype.hasOwnProperty.call(moreModules, moduleId)) {
/******/ 				modules[moduleId] = moreModules[moduleId];
/******/ 			}
/******/ 		}
/******/ 		if(parentJsonpFunction) parentJsonpFunction(data);
/******/ 		while(resolves.length) {
/******/ 			resolves.shift()();
/******/ 		}
/******/
/******/ 		// add entry modules from loaded chunk to deferred list
/******/ 		deferredModules.push.apply(deferredModules, executeModules || []);
/******/
/******/ 		// run deferred modules when all chunks ready
/******/ 		return checkDeferredModules();
/******/ 	};
/******/ 	function checkDeferredModules() {
/******/ 		var result;
/******/ 		for(var i = 0; i < deferredModules.length; i++) {
/******/ 			var deferredModule = deferredModules[i];
/******/ 			var fullfilled = true;
/******/ 			for(var j = 1; j < deferredModule.length; j++) {
/******/ 				var depId = deferredModule[j];
/******/ 				if(installedChunks[depId] !== 0) fullfilled = false;
/******/ 			}
/******/ 			if(fullfilled) {
/******/ 				deferredModules.splice(i--, 1);
/******/ 				result = __webpack_require__(__webpack_require__.s = deferredModule[0]);
/******/ 			}
/******/ 		}
/******/ 		return result;
/******/ 	}
/******/
/******/ 	// The module cache
/******/ 	var installedModules = {};
/******/
/******/ 	// object to store loaded and loading chunks
/******/ 	var installedChunks = {
/******/ 		3: 0
/******/ 	};
/******/
/******/ 	var deferredModules = [];
/******/
/******/ 	// 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;
/******/ 	}
/******/
/******/ 	// This file contains only the entry chunk.
/******/ 	// The chunk loading function for additional chunks
/******/ 	__webpack_require__.e = function requireEnsure(chunkId) {
/******/ 		var promises = [];
/******/
/******/
/******/ 		// JSONP chunk loading for javascript
/******/
/******/ 		var installedChunkData = installedChunks[chunkId];
/******/ 		if(installedChunkData !== 0) { // 0 means "already installed".
/******/
/******/ 			// a Promise means "currently loading".
/******/ 			if(installedChunkData) {
/******/ 				promises.push(installedChunkData[2]);
/******/ 			} else {
/******/ 				// setup Promise in chunk cache
/******/ 				var promise = new Promise(function(resolve, reject) {
/******/ 					installedChunkData = installedChunks[chunkId] = [resolve, reject];
/******/ 				});
/******/ 				promises.push(installedChunkData[2] = promise);
/******/
/******/ 				// start chunk loading
/******/ 				var head = document.getElementsByTagName('head')[0];
/******/ 				var script = document.createElement('script');
/******/
/******/ 				script.charset = 'utf-8';
/******/ 				script.timeout = 120000;
/******/
/******/ 				if (__webpack_require__.nc) {
/******/ 					script.setAttribute("nonce", __webpack_require__.nc);
/******/ 				}
/******/ 				script.src = __webpack_require__.p + "" + ({}[chunkId]||chunkId) + ".[chunkhash].js";
/******/ 				var timeout = setTimeout(function(){
/******/ 					onScriptComplete({ type: 'timeout', target: script });
/******/ 				}, 120000);
/******/ 				script.onerror = script.onload = onScriptComplete;
/******/ 				function onScriptComplete(event) {
/******/ 					// avoid mem leaks in IE.
/******/ 					script.onerror = script.onload = null;
/******/ 					clearTimeout(timeout);
/******/ 					var chunk = installedChunks[chunkId];
/******/ 					if(chunk !== 0) {
/******/ 						if(chunk) {
/******/ 							var errorType = event && (event.type === 'load' ? 'missing' : event.type);
/******/ 							var realSrc = event && event.target && event.target.src;
/******/ 							var error = new Error('Loading chunk ' + chunkId + ' failed.\n(' + errorType + ': ' + realSrc + ')');
/******/ 							error.type = errorType;
/******/ 							error.request = realSrc;
/******/ 							chunk[1](error);
/******/ 						}
/******/ 						installedChunks[chunkId] = undefined;
/******/ 					}
/******/ 				};
/******/ 				head.appendChild(script);
/******/ 			}
/******/ 		}
/******/ 		return Promise.all(promises);
/******/ 	};
/******/
/******/ 	// 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/";
/******/
/******/ 	// on error function for async loading
/******/ 	__webpack_require__.oe = function(err) { console.error(err); throw err; };
/******/
/******/ 	var jsonpArray = window["webpackJsonp"] = window["webpackJsonp"] || [];
/******/ 	var oldJsonpFunction = jsonpArray.push.bind(jsonpArray);
/******/ 	jsonpArray.push = webpackJsonpCallback;
/******/ 	jsonpArray = jsonpArray.slice();
/******/ 	for(var i = 0; i < jsonpArray.length; i++) webpackJsonpCallback(jsonpArray[i]);
/******/ 	var parentJsonpFunction = oldJsonpFunction;
/******/
/******/
/******/ 	// run deferred modules from other chunks
/******/ 	checkDeferredModules();
/******/ })
/************************************************************************/
/******/ ([]);

dist/main.[chunkhash].js

(window["webpackJsonp"] = window["webpackJsonp"] || []).push([[0],[
/* 0 */
/*!********************!*\
  !*** ./example.js ***!
  \********************/
/*! no static exports found */
/***/ (function(module, exports, __webpack_require__) {

// some module
__webpack_require__.e(/*! import() */ 1).then(function() { var module = __webpack_require__(/*! ./async1 */ 1); return typeof module === "object" && module && module.__esModule ? module : { /* fake namespace object */ "default": module }; });
__webpack_require__.e(/*! import() */ 2).then(function() { var module = __webpack_require__(/*! ./async2 */ 2); return typeof module === "object" && module && module.__esModule ? module : { /* fake namespace object */ "default": module }; });


/***/ })
],[[0,3]]]);

Info

Unoptimized

Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 4.0.0-beta.2
                    Asset       Size  Chunks             Chunk Names
        main.[chunkhash].js  768 bytes       0  [emitted]  main
           1.[chunkhash].js  270 bytes       1  [emitted]  
           2.[chunkhash].js  264 bytes       2  [emitted]  
runtime~main.[chunkhash].js   7.49 KiB       3  [emitted]  runtime~main
Entrypoint main = runtime~main.[chunkhash].js main.[chunkhash].js
chunk    {0} main.[chunkhash].js (main) 58 bytes ={3}= >{1}< >{2}< [initial] [rendered]
    > ./example main
    [0] ./example.js 58 bytes {0} [built]
        single entry ./example  main
chunk    {1} 1.[chunkhash].js 29 bytes <{0}> <{3}> [rendered]
    > ./async1 [0] ./example.js 2:0-18
    [1] ./async1.js 29 bytes {1} [built]
        import() ./async1 [0] ./example.js 2:0-18
chunk    {2} 2.[chunkhash].js 29 bytes <{0}> <{3}> [rendered]
    > ./async2 [0] ./example.js 3:0-18
    [2] ./async2.js 29 bytes {2} [built]
        import() ./async2 [0] ./example.js 3:0-18
chunk    {3} runtime~main.[chunkhash].js (runtime~main) 0 bytes ={0}= >{1}< >{2}< [entry] [rendered]
    > ./example main

Production mode

Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 4.0.0-beta.2
                    Asset       Size  Chunks             Chunk Names
           0.[chunkhash].js   77 bytes       0  [emitted]  
           1.[chunkhash].js   78 bytes       1  [emitted]  
runtime~main.[chunkhash].js   1.76 KiB       2  [emitted]  runtime~main
        main.[chunkhash].js  269 bytes       3  [emitted]  main
Entrypoint main = runtime~main.[chunkhash].js main.[chunkhash].js
chunk    {0} 0.[chunkhash].js 29 bytes <{2}> <{3}> [rendered]
    > ./async2 [0] ./example.js 3:0-18
    [1] ./async2.js 29 bytes {0} [built]
        import() ./async2 [0] ./example.js 3:0-18
chunk    {1} 1.[chunkhash].js 29 bytes <{2}> <{3}> [rendered]
    > ./async1 [0] ./example.js 2:0-18
    [2] ./async1.js 29 bytes {1} [built]
        import() ./async1 [0] ./example.js 2:0-18
chunk    {2} runtime~main.[chunkhash].js (runtime~main) 0 bytes ={3}= >{0}< >{1}< [entry] [rendered]
    > ./example main
chunk    {3} main.[chunkhash].js (main) 58 bytes ={2}= >{0}< >{1}< [initial] [rendered]
    > ./example main
    [0] ./example.js 58 bytes {3} [built]
        single entry ./example  main