Webpack 4 Dynamic Import


Read that first if you are new to components. Webpack can not know in advance if the dynamic import is going to be used at some point, so in those cases, you can not apply Tree Shaking and cannot be sure that dynamic imports will never be. Using NPM and Webpack to import TweenLite, ScrollToPlugin, Draggable, ES6 Sign in to follow this. Currently, the src/router. We observed that the first 4 chunks include all modules which are shared among 7,6,5,5 async chunks respectively and the last one is its own chunk. You would import the latter with:. For more information see webpack's documentation on dynamic requires. Two pieces are needed for this approach: A module that contains helpers and standard library. 🐠 Automatic transforms. For example: chunks: there are 3 possible values "initial", "async" and. For these tiny modules, it doesn’t make sense to split the code, but it does serve is a simple example. Regarding problem #1. It's an excellent alternative to the SystemJS approach used elsewhere in the documentation. ` 我删除了UglifyJsPlugin但仍然产生相同的错误. This page is specifically for people using the Webpack bundler. js’; Es que Webpack no puede saber a priori si el dynamic import va a llegar a ser usado en algún momento, por lo que en esos casos no puede aplicar Tree Shaking y no puede descartar dynamic imports que no vayan a ser usados jamás. Webpack HTML plug-in in a Nutshell Published on 23 January 2016 I have been using Webpack for several months now, and I ended up to some more optimized solutions than the one given in the Webpack introduction post. Change tags to apply to the entry in the import log and to the null revision on the imported pages. Give webpack a second and see the bundle come to life in dist/main. So basically we want our code split, which is no big of a deal with the WebPack. I'm trying to migrate my app to webpack 4. It's an excellent alternative to the SystemJS approach used elsewhere in the documentation. 1 升级webpack 4. angular2 documentation: Angular 2 webpack setup. Webpack and TypeScript do support dynamic import but only when the module option is set to " esnext ". If you want to transform it then see dynamic-import-webpack or dynamic-import-node. However, it will assume the entry point of your project is src/index and will output the result in dist/main. In old versions of Webpack (v1), we commonly used the AMD "require" or the specific Webpack "require. 75M,已经算很大了:. 28 in favor of import(). js中添加 watch: true 配置,打包一次之后每次代码更新后都会自动进行打包而无需. webpack 2 offers native support for ES modules. I have been able to get the majority of this work (HTML, SCSS, CSS, JS compiling). Change tags to apply to the entry in the import log and to the null revision on the imported pages. You will receive a link and will create a new password via email. Import a specific item from a source module, with a custom name assigned upon import. Dynamic import is a TC39 proposal in stage 3. Dynamic imports - this is my method of code splitting (page by page). js and webpack, you can use Rollup to compile to UMD or CommonJS format, In case a dynamic import is passed a string as argument,. As the import method returns a promise, you can handle the injection of your code using async await. 5 dependency in it's own node_modules. The dynamic approach uses Webpack’s implementation of the import method to load our code. CommonJS modules). Using multiple entry points in Webpack If you’re looking to add multiple entry points in React, it’s likely you’re maintaining multiple pages or applications (this is the intent of the feature). js minified and optimized for production. Thankfully ES6 dynamic imports proposal (read also here), together with Webpack chunking, comes very handy and allows us to lazy load such dependencies only when they are really needed. Code-Splitting is a feature supported by bundlers like Webpack, Rollup and Browserify (via factor-bundle) which can create multiple bundles that can be dynamically loaded at runtime. NODE_ENV", with the current build mode as it compiles his JavaScript and TypeScript applications. 0 is a major release to the most powerful module bundler for JavaScript applications. Synthesis and Place & Route of specified logic for various Xilinx FPGAs and CPLDs. sass files in a. Treeshaking will only work with Webpack 4 in production mode. x (for longer than I'd like to admit) it all suddenly clicked. Webpack allows you to load images dynamically based on a condition. To quote the release blog post:. The benefits and ability of using @ngtools/webpack standalone from the Angular CLI as presented in Stephen Fluin's Angular CLI talk at Angular Connect 2016: Compiles Sass/Less into CSS TypeScript transpilation. It installs the polyfills globally. Migrating to Webpack 4 is pretty straightforward. new dynamic import. Environments which do not have builtin support for Promise, like Internet Explorer, will require both the promise and iterator polyfills be added manually. Webpack and dynamic import. With Webpack 3, you do not need them in this use case (frontend only react app). Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you. dynamic import不知道为什么有很多叫法,什么按需加载,懒加载,Code Splitting,代码分页等。总之,就是在SPA,把JS代码分成N个页面份数的文件,不在用户刚进来就全部引入,而是等用户跳转路由的时候,再加载对应的JS文件。. Dynamic partitioning fields should be mapped to database columns that are defined with the NOT NULL attribute (although this is not validated). babelLoader has the @babel/plugin-syntax-dynamic-import plugin; Some of the optimizations may not be needed in your case, but this webpack config enables the WebPack 4 almost-automatic code splitting to take place. 4 dependency was moved/hoisted to the root node_modules directory and webpack got it's own [email protected] It breaks in my Angular demo (which uses Webpack 4. Dynamic import with the mode. babel-plugin-dynamic-import-webpack - Babel plugin to transpile import() to require. Webpack needs a lot of configuration options to work correctly. ts Add compilerOption module as " esnext ". The future of this plugin is uncertain after contributors made it clear that they won't be fixing problems with ETWP and CSS extraction support will be moved to MCEP plugin. Read that first if you are new to components. This ability allows for non-critical assets to be loaded in the background during the browser's idle time so that they are ready when a user requests them creating a better user experience. 0 is a major release to the most powerful module bundler for JavaScript applications. I encourage you to use AOT because it shows a lot of problems that are not visible otherwise and it makes the application MUCH faster. ensure() is specific to webpack and superseded by import(). 0's codename) ships with notable additions and ensures build times are now about 98% faster. It installs the polyfills globally. This will make it easy to optimize Angular's performance in a production build. Code splitting and tree shaking with Typescript and Webpack Christian H. This involves Webpack itself, as well as a list of loaders and plugins we’ll need for Angular, TypeScript, and unit testing. This mechanism can be confusing, and makes interfacing with a dynamic library awkward. 🐠 Automatic transforms. 4 (35 ratings) Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately. 前面的syntax-dynamic-import 就是为这里准备的。4. I have been able to get the majority of this work (HTML, SCSS, CSS, JS compiling). js module, not a JSON file. I am getting 404s in production bundle on dynamic chunking. js配置中添加字段 optimization 首先在这里简单提一下 optimization 里面可以配置 tree shaking webpack的代码分割配置代码,异步加载模块配置 2019年11月13日 - 硕大天地,能否有一片净土 2019年11月13日 - 恭喜你,并没有激怒我。我. Note: next. js中添加 watch: true 配置,打包一次之后每次代码更新后都会自动进行打包而无需. We’re running into an issue with the combination of Spartacus, Angular and Storybook. I would love to have a better solution for this but below is an example with the comments added:. Please make sure you are at least familiar with the examples provided in them. org/webpack/webpack-cli. Webpack is a popular module bundler, a tool for bundling application source code in convenient chunks and for loading that code from a server into a browser. cssa file), which is webpack specific features, other possible packaged program or task execution is not supported. 2 (original post on 2016-06-01, then updated on 2017-03-14 for anglar 4. The final step is for webpack to seal the graph and creates the bundle. One of the most exciting features to ship with TypeScript 2. With either the System. 0版本新特性介绍,小编觉得挺不错的,现在分享给大家,也给大家做个参考。一起跟随小编过来看看吧. If you’re bundling front-end assets, chances are you’re using a tool to do it. The future of this plugin is uncertain after contributors made it clear that they won't be fixing problems with ETWP and CSS extraction support will be moved to MCEP plugin. The fix is simple: change the "module" configuration to "esnext". js file has the following code: which uses the import function to dynamically import a Vue component. storybook/main. Code splitting can be done in two primary ways in webpack: through a dynamic import or require. However, it will assume the entry point of your project is src/index and will output the result in dist/main. Although the specification for import() supports a dynamic importing of modules in the browser runtime, webpack's require. In this tutorial we will see the basics of Webpack for React to get you started, including React Router, Hot Module Replacement (HMR), Code Splitting by Route and Vendor, production configuration and more. So we will need to update three files in this case: 1. With either the System. Webpack 4: Beyond the Basics Section 5 - Server Side Rendering & Dynamic Importing\lesson 26 - Server Side Render any Filetype with Webpack. Webpack allows the dynamic import of part of an application. StackBlitz - The online code editor for web apps. npm install babel-core \ babel-preset-es2015 \ browser-sync \ gulpjs/gulp#4. import {Phone} from ". Dynamic imports is a method of code-splitting that allow us to easily split our JavaScript components, packages, and other modules into separate files. Solution is quite simple as is stated in Webpack Module Methods documentation there is multiple options to tell webpack how to bundle your application. The worst part (IMO) is how fragile everything is. Out of the box, webpack won't require you to use a configuration file. Code splitting and tree shaking with Typescript and Webpack Christian H. The paths on the client need to be right. If you are using ES6's import syntax in your application's entry point, you should instead import the polyfill at the top of the entry point to ensure the polyfills are loaded first: import "@babel/polyfill"; With webpack, there are multiple ways to include the polyfills: When used alongside @babel/preset-env,. js now boots up to 57% faster during development. Webpack 4 course - part five. Juni Brosas. Well, that's a recent feature implement inside version 2. Behold the mystery revealed: I always start with the package. extensions. are all exported into the destination folder specified in the Webpack configuration file. Although the specification for import() supports a dynamic importing of modules in the browser runtime, webpack's require. Download the-webpack-ng - 15. ensure() is specific to webpack and superseded by import(). eslint-import-resolver-webpack eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react Extract Text Plugin fs-readdir-recursive git-revision-webpack-plugin html-es6-template-loader html-webpack-plugin identity-obj-proxy immutable Jest jquery. Support for constants (also known as "immutable variables"), i. js --open --watch 你可以通过命令行配置端口等,也. Code splitting with webpack dynamic import in React Share this on This post is a practical approach to the concept of code splitting in frontend apps with React. It's just somehow, Webpack couldnot recognize path in dynamic import. This is a dynamic file name part will be replaced by the name of the entry file i. Impedance phase angle. 0 is a major release to the most powerful module bundler for JavaScript applications. Which tell webpack to bundle the dynamic import into the current chunk. The benefits and ability of using @ngtools/webpack standalone from the Angular CLI as presented in Stephen Fluin's Angular CLI talk at Angular Connect 2016: Compiles Sass/Less into CSS TypeScript transpilation. To quote the release blog post:. Let's see a small example. The paths on the client need to be right. For more information on the reason behind this, read webpack 4: import() and CommonJs. Next webpack walks the graph and seals it together and then it applies plugins. This article explores the new features and improvements in Webpack 4. babelLoader has the @babel/plugin-syntax-dynamic-import plugin; Some of the optimizations may not be needed in your case, but this webpack config enables the WebPack 4 almost-automatic code splitting to take place. webpack 4, mostly in response to the Parcel success, introduced a zero-config mode, with some conventions, rather than always requiring a configuration. Keep in mind that you will still probably need babel for other ES6+ features. It breaks in my Angular demo (which uses Webpack 4. Configuration. New here? Start with our free trials. September 15, 2019 at 4:06pm. js is being used. That said, we're always. In all other modules (in each entry) we only import jQuery. Keep in mind that you will still probably need babel for other ES6+ features. Webpack is a wonderful tool for bundling front-end assets. And that tool, most likely, is webpack. In this tutorial we will see the basics of Webpack for React to get you started, including React Router, Hot Module Replacement (HMR), Code Splitting by Route and Vendor, production configuration and more. Having said that, it can sometimes be a bit confusing to newcomers who switch over from a more traditional "concatenate these scripts and libraries in this exact order" setup. Important note about import. To quote the release blog post:. Webpack 4 course - part eight. import {Phone} from ". I'm trying to migrate my app to webpack 4. Dynamic import with the mode. Subscribe to this blog. With the dynamic imports proposal, we got an additional, dynamic way to import modules. NPM Install Webpack Plugin Speed up development by automatically installing & saving dependencies with Webpack. The dynamic approach uses Webpack's implementation of the import method to load our code. Webpack roams over your application source code, looking for import statements, building a dependency graph, and emitting one or more bundles. 各位,我不是说 build,是说实时编辑之后 webpack 进行编译(然后去 chrome 那里调界面)。因为脚本我的理解,应该就是免编译即使改即使出来的,但是现在感觉越来越重了,哪怕我改个变量也要等半天,毕竟 js 是动态的,很多东西都是未知的. José Quinto. chunk 是在 webpack process 中的許多 modules;bundle 則是射出的 chunk 或許多 chunks。 注意:在 Webpack 4 中有部分 API 有變動,若下面文章有無法使用的,可以參考 webpack 4 announcement @ GitHub issues 查看更新項目。 最陽春的 webpack 設定. Code splitting with webpack dynamic import in React. ##Folder structure. in - Buy React Cookbook: Create dynamic web apps with React using Redux, Webpack, Node. It might be useful to go through an earlier blog I wrote on Understanding Webpack for a tutorial on Webpack core concepts and ideas. The JSON configuration files (npm (package. ) are complex and the documentation is awful. You will definitely want to get to the end of this course. It worked really well once you got it configured, and wSokra was incredibly helpful and supportive in the chat room; but if you didn't have a known-working config and/or access to wSokra, well, good luck. Important note about import. 4 External dependencies via module imports 5. NET Core MVC view using Webpack to build the Angular application. i ve downloaded and all karma dependencies. 0版本新特性介绍,小编觉得挺不错的,现在分享给大家,也给大家做个参考。一起跟随小编过来看看吧. This is a dynamic file name part will be replaced by the name of the entry file i. Using the dynamic import() syntax, Parcel splits your output bundles so you only load what is needed on initial load. "Workbox is a rethink [on] our previous service worker libraries and tools, sw-toolbox and sw-precache, and is designed to be more modular, flexible,. With plugin and rules, Webpack can preprocess and minify different non-JavaScript files such as TypeScript, SASS, and LESS files. Each time webpack encounters a dynamic import like this:. If you need a refresher on what loaders and plugins are as far as Webpack goes, or what a basic webpack. Using with webpack 2. 다음과 같이 주석으로 이름을 지정하게 되면 그룹으로도 지정할 수 있게 됩니다. js: Webpack is a powerful module bundler which building a dependency graph, and emitting one or more bundles. Dynamic imports - this is my method of code splitting (page by page). 我在之前文章Webpack轻松入门(二)——CSS打包中提到过Webpack中的自动打包功能,很简单,在webpack. Dynamic import expressions are a new feature and part of ECMAScript that allows users to asynchronously request a module at any arbitrary point in your program. ` 我删除了UglifyJsPlugin但仍然产生相同的错误. Next webpack walks the graph and seals it together and then it applies plugins. Webpack 4: Beyond the Basics Section 5 - Server Side Rendering & Dynamic Importing\lesson 26 - Server Side Render any Filetype with Webpack. ae425fe 100644 --- a/NOTICE +++ b/NOTICE @@ -1,149 +1,148 @@ The MIT License: Copyright (c) 2014-2018 Google, Inc. NET Core ready for dev and production builds. This is well explained in the "Load components when needed with Vue async components" on Egghead. Please make sure you are at least familiar with the examples provided in them. I'm trying to migrate my app to webpack 4. json instead of tsconfig. Specifically, the new dynamic import statement,. js'; Namespace Imports. If you have an existing webpack config for your project and want to reuse this app’s configuration, you can either: Import your main webpack config into Storybook’s. The fix is simple: change the "module" configuration to "esnext". To quote the release blog post:. At the time of writing in January 2018, the official TC39 proposal for dynamic import() expressions is at stage 3 of the TC39 process and has been for a while, which means it's likely that. In this beginner-friendly Webpack 4 tutorial, Mark Brown demonstrates how to set up and configure Webpack to transform and bundle all your front-end assets. Oct 8, NOTE: This syntax is only possible with Webpack 2 (for System. An additional benefit of importing the CSS in our code is that we (developers) can see where the association between the CSS and its usage is. 4 dynamic import expressions は 自動的に チャンク化されたバンドルを生成し、最終的なJSバンドルを自動的に分割します。しかし、tsconfig. splitChunks. ensure允许使用可选的第三个参数进行简单的块. ensure() in the code while building. in “Add ‘tsconfig. This article is part of the Webpack from Zero to Hero series, for more background or for the index you can check the "Chapter 0: History". 0版本新特性介绍,小编觉得挺不错的,现在分享给大家,也给大家做个参考。一起跟随小编过来看看吧. In order to do that, it, in turn, needs the support of UglifyJS and Babel. Plugins are defined in the webpack config file, and there are also internal plugins that webpack calls automatically without your configuration. The final step is for webpack to seal the graph and creates the bundle. new dynamic import. Hi jfabian, There is no example and it looks okay. ensure" to dynamic load modules. Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you. With webpack 4, code splitting should be enabled by default without any extra work! This is great because it makes it easy to get started. storybook/main. js and it was fun and pretty straight-forward to finish it. For more information see webpack's documentation on dynamic requires. A dynamic pivot table is a great way to summarize data. Webpack is critical for faster build times to tweak the performance of website or web app. The magic behind the hood is all done by Webpack. Code splitting with SplitChunksPlugin5. The use of System. keep-alive with Dynamic Components. Code splitting is one of the most compelling features of webpack. js file looks like, check out this article [https. Webpack plugin to track time spent working on a webpack project. Powered by. There are really two problems contributing to this. mp4 Section 5 - Server Side Rendering & Dynamic Importing\lesson 27 - Server Side Render JS with Express and React. x (for longer than I’d like to admit) it all suddenly clicked. In all other modules (in each entry) we only import jQuery. I just need to replace our current gulp build task with webpack 4. 以上代码在你的项目中被打包过后,你会发现Webpack在utilities文件夹下为每个模块单独创建了异步chunk。这是因为Webpack不能在编译时知道哪些模块需要被导入。 你还需要知道像import(pathToFile)这样的完全的动态声明是不起作用的,因为Webpack至少需要一部分文件路径信息。. Importing Webix as Module. Import Path Resolver. ensure allows for easy chunk naming with the optional third argument, but import API doesn't offer that capability yet. A dynamic import is when an imported file is only known at runtime: When you're bundling this with … Continue reading "How webpack's ContextReplacementPlugin works". We can determine what Webpack does and how it does it with a JavaScript configuration file. 4 dynamic import expressions は 自動的に チャンク化されたバンドルを生成し、最終的なJSバンドルを自動的に分割します。しかし、tsconfig. The import statement cannot be used in embedded scripts unless such script has a type="module". js but no effect :. NET Core ready for dev and production builds. Parcel has out of the box support for JS, CSS, HTML, file assets, and more - no plugins needed. json), Typescript, Karma, Webpack, etc. Webpack dynamic import with variable + externals config not working 0 I'm trying to use a dynamic import that uses a variable, and at the same time leave all these modules as external libraries, so I'm doing this:. Code: VS2017 angular 4. With Webpack 3, you do not need them in this use case (frontend only react app). Getting started with Webpack Ahead-of-Time Configuration To quick start with Syncfusion JavaScript Angular components run the below commands to clone the repository for Webpack starter and installing required dependency packages. js and Rhino) or client-side (modern browsers only). This is a 500 pages concise technical eBook available in PDF, ePub (iPad), and Mobi (Kindle). Code splitting with webpack dynamic import in React. Search posts: it's natural to think (if we are using webpack in our dev workflow) that by using TypeScript 2. But I can't get it to work. Since the release of Webpack 4, extract-text-webpack-plugin is completely broken. 6+, this comes built in where you can manually specify which dependencies you want to preload or prefetch using inline import directives which Webpack will automatically output as resource hits without the need to install the plugins I mentioned above. Webpack 4 course - part three. Here, we wait for Webpack's HMR plugin to inform us that ReloadRoot has been updated. i ve downloaded and all karma dependencies. Because it’s still a proposal, browsers do not support it yet. In order to do that, it, in turn, needs the support of UglifyJS and Babel. Angular Version I have used – 4. Entry, output and ES6 modules2. Dynamic import is a TC39 proposal in stage 3. js file looks like, check out this article [https. With a very minor tweak to our Webpack configuration, we can get it to load files relative to the app root. keep-alive with Dynamic Components. This is a note on Webpack, @Angular and miscellaneous topics. But when you use import() like a function. The resulting bundle will be placed inside a tag. are all exported into the destination folder specified in the Webpack configuration file. Webpack version 4 is as fast as the Flash, okay maybe not that fast but its faster than previous versions of Webpack. json” section, it seems like you attached the code same as the package. Babel provides the dynamic-import-webpack plugin for such a syntax, which you can install and your import() operators will be processed by it. NET core using webpack, a JavaScript library, so that we can start focusing on writing Angular features rather than spending time in setting up an environment to run. Make sure to include stage-0 in your babel presets. The dynamic import Proposal. I have tried to convert them to lowercase, but still same issue. When I startup my project and go to a page which doesn't use this component, I can still found that webpackJsonp sometimes is function, and sometimes is array. UPDATE: If you're now using Webpack 3, On Frontend Engineering. You will notice that compiling still takes a lot of time if you try this example. import a module on-demand (or conditionally) compute the module specifier at runtime; import a module from within a regular script (as opposed to a module) None of those are possible with static import. Webpack - using the dynamic import() May 09, 2017 in javascript , webpack I recently implemented some big optimizations for the company that I work for and I wanted to share with you how I tackled the topic step by step. This tutorial explains how to use webpack dynamic imports to make your application faster. The resulting bundle will be placed inside a tag. With plugins and rules, Webpack can preprocess and minify different non-JavaScript files such as TypeScript, SASS, and LESS files. The static import statement is used to import bindings which are exported by another module. 4,normal,normal,29,Awaiting Review,feature request,new,,2015-08-20T21:01:36Z,2017-09-18T15:12:07Z,"Templating engines are being used everywhere, not just in other languages, but nearly all. 9: Maven; Gradle; SBT; Ivy; Grape; Leiningen; Buildr. Webpack 4 course: what are dynamic imports? Back in the days, ECMAScript modules were completely static. diff --git a/NOTICE b/NOTICE index e4989be. 透過 dynamic import 的機制引入程式碼 如果我們要在 component 當中動態引入對應的 module 的話,最方便的方法應該是透過 dynamic import 的機制。它能夠讓 import() 變成一個 return Promise 的函數,在 webpack build 的時候,會自動把這些檔案拆分出來. For Babel transpiling, you also need the babel-plugin-syntax-dynamic-import plugin, to allow Babel parse dynamic import() correctly. So whatever your interest, you can always find fresh thinking and unique perspectives. 🐠 Automatic transforms. Code splitting and tree shaking with Typescript and Webpack. Webpack 4 course – part one. You will receive a link and will create a new password via email. webpack; plugin; vendor; vendors; import; dynamic-import; dynamic-vendor-webpack-plugin; Publisher. Read React Cookbook: Create dynamic web apps with React using Redux, Webpack, Node. An Annotated webpack 4 Config for Frontend Web Development As web devel­op­ment becomes more com­plex, we need tool­ing to help us build mod­ern web­sites. And that tool, most likely, is webpack. Stage 4 is the "finished" stage, so it's getting really close to becoming a standard. This is how TypeScript translates the dynamic import() for the "commonjs" setting. 4 KB; Download the-good-old-systemjs - 8. 1 Helpers and standard library via imports: babel-plugin-transform-runtime. This tutorial explains how to use webpack dynamic imports to make your application faster. js is a regular Node. Because it's still a proposal, browsers do not support it yet. The following methods are supported by webpack: import. splitChunks option allows the main. 다음과 같이 주석으로 이름을 지정하게 되면 그룹으로도 지정할 수 있게 됩니다. This mechanism can be confusing, and makes interfacing with a dynamic library awkward. It will do everything out of the box. Importing Webix as Module. When I first started using Webpack 4 years ago, it had the most finnicky, difficult-to-configure (perhaps even magic) API I can think of. With webpack 4, a new way of extracting CSS from bundles was introduced, called mini-extract-css-plugin. amCharts 4 has excellent support for Webpack. Webpack will automatically resolve and add the imports during transpilation using the module rule and loader we added in the previous step. 本篇文章主要介绍了webpack 4. It worked really well once you got it configured, and wSokra was incredibly helpful and supportive in the chat room; but if you didn't have a known-working config and/or access to wSokra, well, good luck. A null value during import for a dynamic partitioning column will abort the Sqoop job. Webpack 4 course – part one. 使用 "module": "esnext" 选项:TypeScript 保留 import() 语句,该语句用于 Webpack Code Splitting。; 进一步了解有关信息,推荐阅读这篇文章:Dynamic Import Expressions and webpack 2 Code Splitting integration with TypeScript 2. Read that first if you are new to components.