Babel Polyfill Fetch

If omitted, fetch page 1. Code everything in Typescript. babelrc 文件读取配置。. JSFiddle or its authors are not responsible or liable for any loss or damage of any kind during the usage of provided code. Release date: 2017-10-05. That gets even better with methods like. Libraries We Use. I recently developed a ReactJS application and of course I used the ES6 syntax along with Babel and various other polyfills. CSS Grid Polyfill playground. Introduction. Provides polyfills necessary for a full ES2015+ environment. Window, fetch and promises. A fetch group holds an ordered list of fetch records. This package has been deprecated in favor of separate inclusion of required parts of core-js and regenerator-runtime. 8% of the global population uses IE8 and 0. Get Started with webpack, Rollup or Parcel. At home, I’m using Visual Studio 2019, NodeJS 10. js ), to ensure its executed just before the rest of the app loads:. Fetch API を利用すると、リクエストやレスポンスといった HTTP のパイプラインを構成する要素を操作できるようになります。 。また fetch() メソッドを利用することで、非同期のネットワーク通信を簡単にわかりやすく記述できるようになり. You can use promises and fetch and arrow functions and const and let - all the hip new gear - and it. Thanks to our Thunk middleware, our app will wait until this promise is resolved, and then dispatch the our action object with keys of type and either errors or distributions to our distributions reducer. io (or your own, newly installed Polyfill. babel-node – Run node cli with ES6 transpiling using Babel. entry: ['babel-polyfill', 'whatwg-fetch','. Entry Point index. Hi realone01, try deleting Temporary Internet Files, History and Cookies. EDIT: Forgot some of the details from before, but it's pretty clear there is some polyfill issue with IE11 and Symbols. Using Fetch. babel-polyfill / babel-runtime それぞれ内部的にcore-jsを利用している。 「じゃあ core-js を直接使うのはどうなのだろう? 」と考えた(regenerator-runtimeについては個人的にあまりお世話にならない都合で割愛させていただく。. Babel includes a polyfill that includes a custom regenerator runtime and core-js. OK, I Understand. polyfill() in alcuni tutorial ma idk perché essi erano in uso. In this post we'll see how to fix regeneratorRuntime and and how to handle errors with Fetch and async/await. npm install @wordpress/api-fetch --save This package assumes that your code will run in an ES2015+ environment. It doesn’t, can’t convert arbitrary browser APIs like fetch. io with Babel. Fetch polyfill 的基本原理是探测是否存在 window. The recommendations below represent the collective knowledge of developers who have been deep in the HTML5 trenches. ajax() ES6 arrow functions; Polymer bidirectional databinding + Chrome console debugging (aka $0. Babel CLI --out-dir runs into permissions errors on second compile Why does Karma fail to add the global babel polyfill? How to find variable declarator for an identifier using Babel?. Babel doesn't add polyfill for web specifications. Eveo - Senior Frontend Developer Oct 2012 - Jun 2015. This is a prototype for a 'visual-storytelling-through-maps' app, aka locations and pretty pictures. Quindi, se l’importazione di es6-promessa che ho bisogno di chiamare promessa. Refer to Babel's interactive setup guide for more information. Walsh, a condizione che funziona e richiede solo di importare il recupero ‘isomorfi-fetch”. $ npm install url-search-params-polyfill --save For Babel and ES2015+, make sure to import the file: but browsers which have fetch support and not URLSearchParams. Web pages should first import any polyfill scripts, then import Vega:. The proposal recently hit the candidate stage (stage 3) and is in need of usage and feedback. babelrc There are a few different changes needing to be made. Symfony Polyfill. If you aren’t using a boilerplate, you’ll need to install and configure Babel and Webpack yourself. As I was researching that Chrome 52 bug yesterday, my friend Smotko showed me something cool: fetch(). With the Fetch API and ES2017 features like Async/Await this could change now. A fetch group holds an ordered list of fetch records. 可也许你还是面对着不敢直接使用 fetch 或是 Object. By default, webpack will polyfill each library if there is a known polyfill or do nothing if there is not one. You can only use polyfills to implement ECMAScript's proposals listed here. babel-polyfill allows you to use the full set of ES6 features beyond syntax changes. 2) Create new branch and apply patch to new branch. To be able to use fetch inside Node. Summarized, Encore generates the Webpack configuration that's used in your webpack. In this last section I want to show you an example with a Parcel / Babel project and Polyfill. You may refer to MDN's guide on Using Fetch for additional information. React为了引入JSX,必须需要引入编译,这又间接促成Babel与webpack的壮大。尤其是Babel, 让我们在很旧的浏览器中使用非常新的语法,甚至一些还没有定案的语法。React从14升级到React 15,强制使用class语法,让这个推了好久的语法糖终于大规模落地。. 10 Closure 2018. io/ to load the required polyfills. The solution is quite simple. in this way, your need use babel to compile,. If you are using React through create-react-app then you are already using the transpiler Babel which converts all of your fancy classes, arrow functions, const and. Updated domain-wait package. If omitted, fetch page 1. Forcing IE to bust caches on AJAX get requests. With BootstrapVue you can build responsive, mobile-first projects on the web using Vue. and checked that the initial app from the template works in the. 4 abortcontroller-polyfill @1. EDIT: Forgot some of the details from before, but it's pretty clear there is some polyfill issue with IE11 and Symbols. What happened next was a little bit of this: Followed by a lot of this: In case you don't know, superagent is a popular library for executing AJAX requests in JavaScript. babelrc or babel. NET apps, Glimpse is a NuGet packages that provides detailed performance, It is fast, super-light and serve developer with best visual display for all performance metrices. This include the below versions. # Polyfills when Building as Library or Web Components. The polyfill is included already, that's why I was saying that my test will pass if I use e. 引入 fetch 的 polyfill: fetch-ie8 5. All this without having 2 codebases. For example if you use fetch in your JavaScript, babel will not provide fallback support (this is called “polyfill“-ing) because fetch is a Web API and not part of JavaScript proper. To set up my development environment, I started an Android emulator and my code editor. November 10, 2015 by David Keen · 0 Comment. Hi- The settings you have shown, should work. It’s effectively just fetch with extra superpowers! Let’s see this in action by creating a new HTML5 project: # Create directory with a name of your choosing $ mkdir axios-js && cd axios-js # Create files $ touch index. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. The fetch() function is a Promise-based mechanism for programmatically making web requests in the browser. This fork supports IE8 with es5-shim, es5-sham and es6-promise. In browsers that don't support it, provide a "good enough" polyfill. Fetch polyfill 的基本原理是探测是否存在 window. Let’s fix the main difference between Node. 5 whatwg/fetch @2. Flattening the API landscape if you will. Finally, one will notice that Create React App also includes a browserlist key in package. Has jQuery Become a Polyfill? jQuery has always been in everyone's JavaScript toolkit, but with the latest release, is it really required to build websites and do we really need it anymore? by. Flattening the API landscape if you will. なぜかfetch as googleで読めず… react-app-polyfill でIE対応すればChrome 41でも動くのでは? なぜかfetch as googleで読めず… 俺が悪かった import 'babel-polyfill' するわ 読めた! JSの容量は増えるが、まあ個人サービスなので目をつぶろう(11KB+だった). by Patrick Hund Testing a React-driven website's SEO using "Fetch as Google" Image credit: myself. Compilers/polyfills Desktop browsers Servers/runtimes Mobile; Feature name Current browser ES6 Trans-piler Traceur Babel 6 + core-js 2 Babel 7 + core-js 2 Babel 7 + core-js 3 Closure 2018. If you are using babel-preset-es2015, just replace it with babel-preset-env and you will get the latest Babel plugins support. Set up NPM build systems using Gulp, Browserify, Jade, and Stylus. While Babel does a good job of applying syntactical transforms to our ES6+ code, built-in features introduced in ES6+ — such as Promise, Map and Set, and new array and string methods — still need to be polyfilled. Today I discovered a strange problem; my Cordova application, which uses the new Fetch API was working fine on iOS, but was failing on Android (with Crosswalk). rant es6 babel polyfill fetch childnode. A cool, newer option for browsers is to use preset-env with the option useBuiltIns to pull in the needed parts of babel-polyfill. Release date: 2017-10-05. JavaScript can fetch() now and it's not THAT great Swizec Teller published on August 12, 2016 in Front End , Technical. In this post we’ll see how to perform HTTP requests using axios. fetch and Headers are undefined in IE11. A preset is a set of plugins. Advanced Webpack Config¶. You don’t have to use the `/api` prefix. npm install ywl-fetch --save;; Usage. Refer to Babel's interactive setup guide for more information. Yet there's a whole world of polyfills out there to let you experiment and use new. So you're using the CLI to build your next Aurelia application and you want to use the Fetch client? You might have noticed by default it does not come configured with the Fetch client. Fetch: fetch needs to be polyfilled because by the definition mentioned earlier, when you compile code you're not adding any new global or primitive properties that you may need. Polyfills — Such as babel-polyfill and isomorphic-fetch to fill gaps where browsers do not provide certain javascript APIs yet Mocha — A Javascript unit testing framework making it easy to write both synchronous and asynchronous tests. The static analysis tools that come with eslint rival most statically typed languages. "Delete your Internet cookies"2. fetch Headers polyfill - 2. Has jQuery Become a Polyfill? jQuery has always been in everyone's JavaScript toolkit, but with the latest release, is it really required to build websites and do we really need it anymore? by. It basically acts like const babel = code => code, parsing the code and then generating the same code back out again. Babel; Browserify; Duo; Grunt; Gulp; Jspm; Webpack; MSBuild; NuGet; Babel # Install # npm install @babel/cli @babel/core @babel/preset-typescript --save-dev. (via tinyify and the latest version of Babel using @babel/preset-env and. Flattening the API landscape if you will. In this snippet, I am looking for Array. js This polyfill is automatically loaded when using babel-node. So, for example, for enough modern target So, for example, for enough modern target useBuiltIns: entry. scroll-behavior - @rill/http will automatically try to use the "smooth" scroll-behavior when scrolling to targets on link clicks. Babel will do this for you, here's an example via the Babel REPL - note how similar the transpiled code is. Window, fetch and promises. The problem is that when the user right-clicks on the placeholder text, the browser's context menu is "wrong", the browser shows the "general" menu instead of the "edit" menu, there is no Paste, Spellcheck, etc. (This decision is being reconsidered. Babel offers some good ways to automate the polyfilling. ascending) enterJS 2015 - Polymer & ES6 in action (hosted by Lars Gersmann. And Babel must be configured to use a bunch of presets: babel preset env for compiling Javascript ES6 code down to ES5 (please note that babel-preset-es2015 is now deprecated). This will emulate a full ES2015+ environment and is intended to be used in an application rather than a library/tool. What happened next was a little bit of this: Followed by a lot of this: In case you don't know, superagent is a popular library for executing AJAX requests in JavaScript. This populates the dependencies in package. js module, please take a look at this page. Best practices for software development teams seeking to optimize their use of open source components. @kaiyoma Are you including babel-polyfill? import 'babel-polyfill'; It wraps the core-js polyfill which includes Symbol support. isomorphic-form-data - Send multipart form data universally (able to send files and works with fetch). As such, we can confirm that both the Babel and fetch polyfills are indeed included with our configuration. Diffchecker is an online diff tool to compare text to find the difference between two text files. Polyfills are great for methods like String. Hi- The settings you have shown, should work. Updated domain-wait package. js This polyfill is automatically loaded when using babel-node. How to implement Promise polyfill for IE? { // load vendor bundle with fetch and promise. …We also use transpiling for languages…like CoffeeScript and TypeScript. Apparently the browser that the Googlebot runs in doesn't include an ES6 Promise implementation. Notable examples include:. StealJS uses babel-standalone internally, any plugin or preset builtin in babel-standalone will work after being declared in the babelOptions object; non-buitin plugins and presets need to be installed through npm first. Destructuring: Babel can transform every destructured object into normal variables using dot notation. signup login tour help xDi. For my project I decided to us the whatwg-fetch fetch polyfill. However, Babel doesn't show any specific polyfills that are used: This is because the entire @babel/polyfill is being imported directly. npm i babel-polyfill. See how to build SPA using Vue. io is pretty comprehensive, and it includes some bleeding-edge browser APIs like Fetch and Promises. So, for example, for enough modern target So, for example, for enough modern target useBuiltIns: entry. js in the Babel type. Svelte そのものの動作については、Babel の導入だけで十分なのですが、IE11 には現在のブラウザであればサポートされているいくつかの機能が不足している部分があるため、それを補完します。. 02 Closure 2019. Exceptions not shown when raised inside a promise. Asynchronous patterns are becoming more common and more important to moving web programming forward. /* After that we have to include 3 polyfills but before code is executed. 刚接触 babel 的同学一开始可能都认为在使用了 babel 后就可以无痛的使用 es2015 了,之后被各种 undefined 的报错无情打脸。一句话概括, babel 的编译不会做 polyfill。那么 polyfill 是指什么呢?. You'll need to chain your module actions from there. As I was researching that Chrome 52 bug yesterday, my friend Smotko showed me something cool: fetch(). json lockfile. Main script to load all the below mentioned additional polyfills: Fetch Polyfill: wp-polyfill-fetch: Polyfill that implements a subset of the standard Fetch specification: Promise Polyfill: wp-polyfill-promise: Lightweight ES6 Promise polyfill for the browser and node: Formdata. ES6+ Polyfills. At home, I’m using Visual Studio 2019, NodeJS 10. Added new React components to prevent a headake when you build web applications: ModalComponent, Input, MultiSelect, Form. Getting data from the browser is done using an XMLHttpRequest or using the new fetch API that is defined on the global object window. jQuery's promises have a poorly thought out API that will likely just confuse you. その他の Polyfill の導入. 刚接触 babel 的同学一开始可能都认为在使用了 babel 后就可以无痛的使用 es2015 了,之后被各种 undefined 的报错无情打脸。一句话概括, babel 的编译不会做 polyfill。那么 polyfill 是指什么呢?. HTML5 Please helps you out with recommendations for polyfills and implementation so you can decide if and how to put each of these features to use. Mocha – A JavaScript unit testing framework making it easy to write both synchronous and asynchronous tests. assign 的难题? babel 和 polyfill. (babel-polyfill has a check so that it can only be required once, and errors out otherwise. 浪子神剑 前端面试每日3+1&前端剑解. Finally, one will notice that Create React App also includes a browserlist key in package. 为什么?我想大家猜到了,因为babel-runtime实现的polyfill是局部实现而不是全局实现,fetch底层实现用到Promise就是从全局中去取的,拿不到这报上述错误。 另外,顺便补充一下fetch的polyfill实现思路是:. /static/ 映射到 /static/ (可以 创建一个静态目录 在你的项目中) 这里有个简单的案例,可以下载看看 sample app - nextgram. It's technically impossible to polyfill them. # Zowe Third Party Library Usage. To be able to use fetch inside Node. In production, these are. io with Babel. Please do not edit this page by hand. December 4th 2016; 40K; A polyfill, or polyfiller, is a piece of code (or plugin) that provides the technology that you, the developer, expect the browser to provide natively. The following are two alphabetical lists of third-party libraries distributed with TeamCity. {"categories":[{"categoryid":387,"name":"app-accessibility","summary":"The app-accessibility category contains packages which help with accessibility (for example. 一开始只用了transform-runtime,后来发现有些es6的方法不能用,比如字符串的includes。后来又在入口文件加上babel-polyfill,能用了。 但不知道babel-runtime能否去掉,babel-polyfill和babel-runtime功能是否有重复?. JavaScript Can fetch() Now and It's Not THAT Great You can use this Babel fetch polyfill to bridge the gap. Making requests. 手写bind()函数,理解MSDN上的标准Polyfill. I’m really excited for the Async/Await proposal to move forward. This module is out of maintanance, use fetch-ie8 instead. fetch Headers polyfill - 2. In this tutorial, you will learn how to ensure that the Javascript you write works in any browser. Aside: Babel doesn’t include Web APIs. This fork supports IE8 with es5-shim, es5-sham and es6-promise. The fetch() Polyfill. So beside annoying code regenerator So beside annoying code regenerator which is required for async await to work, we also need promise and fetch polyfill. asynchronous things like data fetching and impure things like accessing the browser cache) easier to manage, more efficient to execute, easy to test, and better at handling failures. Fetch provides a better alternative that can be easily used by other technologies such as Service Workers. Using babel-polyfill helps with the latter. json and will also generate a jspm. Obsviusly babel-loader makes use of Babel. babel-polyfill @7. assign 的难题? babel 和 polyfill 刚接触 babel 的同学一开始可能都认为在使用了 babel 后就可以无痛的使用 es2015 了,之后被各种 undefined 的报错无情打脸。一句话概括, babel 的编译不会做 polyfill。. However, you still do not get new language features, like arrow functions, template strings, and so on. Example usage modulename. fetch and sinon stubs to test API requests. These files are parsed by one of the. Where polyfill came from / on coining the term. We have very different definitions of easy. babel-polyfill / babel-runtime それぞれ内部的にcore-jsを利用している。 「じゃあ core-js を直接使うのはどうなのだろう? 」と考えた(regenerator-runtimeについては個人的にあまりお世話にならない都合で割愛させていただく。. We thank the open source community for all of their contributions. This result falls beyond the top 1M of websites and identifies a large and not optimized web page that may take ages to load. Besides, there is really no need to use two viewport meta tags here since their contents are virtually identical. Fetch polyfill 的基本原理是探测是否存在 window. fetch and Headers are undefined in IE11. Forcing IE to bust caches on AJAX get requests. If you use one of the options above, you put babel or rollup in charge of the compilation of typescript. Scroll down to find the library name: whatwg-fetch. Finally, one will notice that Create React App also includes a browserlist key in package. H/T @Nexii for pointing this out. But if anyone looks at the source code, it's just like two import statements. difference except that it accepts iteratee which is invoked for each element of array and values to generate the criterion by which they're compared. …There are many different transpiling tools available. They can be challenging to work with in JavaScript. INTELLECTUAL PROPERTY NOTICES. It’s up to you if you want to include the polyfill in the module, or suggest to users that they use it. JavaScript can fetch() now and it’s not THAT great Swizec Teller published on August 12, 2016 in Front End , Technical. yarn add react react-dom redux react-redux redux-logger redux-thunk isomorphic-fetch babel-polyfill # 開発用のライブラリ yarn add --dev webpack babel-core babel-loader babel-preset-es2015 babel-preset-react babel-plugin-transform-class-properties babel-plugin-transform-object-rest-spread. Why is "no-cors" supported in service workers but not the. As such, we can confirm that both the Babel and fetch polyfills are indeed included with our configuration. Example usage modulename. Note: the function is not executed for array elements without values. However, Babel doesn't show any specific polyfills that are used: This is because the entire @babel/polyfill is being imported directly. Using babel-polyfill helps with the latter. This means that both the Promise and fetch APIs are used directly by Parcel’s loadng script in the destination browser, APIs that IE11 doesn’t have. 61 Mb which makes up the majority of the site volume. getElementById('root')) Action Creators and. Notice the inclusion of babel-polyfill on line 7. Main script to load all the below mentioned additional polyfills: Fetch Polyfill: wp-polyfill-fetch: Polyfill that implements a subset of the standard Fetch specification: Promise Polyfill: wp-polyfill-promise: Lightweight ES6 Promise polyfill for the browser and node: Formdata. assign 的难题? babel 和 polyfill. In this example, the message "Symfony is great!" will be translated into the locale set in the constructor (fr_FR) if the message exists in one of the message catalogs. As such, we can confirm that both the Babel and fetch polyfills are indeed included with our configuration. Open in Browser. js like so:. APIPart, onebabel-polyfillAfter compression, it's almost 100k in size, which is really terrible. In browsers that don't support it, provide a "good enough" polyfill. It's effectively just fetch with extra superpowers! Let's see this in action by creating a new HTML5 project: # Create directory with a name of your choosing $ mkdir axios-js && cd axios-js # Create files $ touch index. This is going to be the future of communicating with remote APIs. The compiler for next generation JavaScript. H/T @Nexii for pointing this out. Load polyfills individually # By default, Babel includes every polyfill needed for a complete ES2015+ environment when @babel/polyfill is imported into a file. Provides polyfills necessary for a full ES2015+ environment. Let's move on to our second topic: polyfills. It's a nice new feature of the language when working with async operations like data fetching. Instead I recommend using babel-polyfill. Sometimes this is not enough and you will hav. Для поиска полифила обычно достаточно ввести в поисковике "polyfill", и нужное свойство либо метод. Scroll down to find the library name: whatwg-fetch. babel-polyfill and whatwg-fetch: They are bringing older browsers up to speed. Using polyfills you can use the fetch API. The transform-runtime plugin is a great option if you're building an application targeted for Node. MIT · Repository · Original npm · Tarball · package. Example usage modulename. Please try again later. 更新:随着 babel-preset-es2015 的废弃及 babel-preset-env 的到来,现在有更好的方法来做 polyfill ,详见我的另一篇文章《再见,babel-preset-2015》。 最近在知乎上看到一个问题:Babel 编译出来还是 ES 6?难…. Babel doesn't add polyfill for web specifications. A fetch record has an associated fetch (a fetch algorithm or null). But still have no clue how to include this NPM package npm install --save-dev babel-polyfill. This is in this spirit are babel-plugin-macros designed. Aside: Babel doesn't include Web APIs. 但不管怎样,加载 polyfills 是当今网络上非常普遍的做法。 对 HTTPArchive 数据集的快速查询显示 Alexa 排名靠前的网站,有 85,181个网站在其代码包引入了babel-polyfill,core-js, 或者regenerator-runtime。然而6个月前这个数量仅仅是34,588个。. On this site I load select bits from core-js as well as Github's fetch polyfill. /containers/Root' render(< Root />, document. babel-polyfill / babel-runtime それぞれ内部的にcore-jsを利用している。 「じゃあ core-js を直接使うのはどうなのだろう? 」と考えた(regenerator-runtimeについては個人的にあまりお世話にならない都合で割愛させていただく。. On the server, you don’t need a compiler—you can start using for – of in io. To generate the polyfill bundle, I recommend using a module bundler like Webpack or Browserify and simply require each of the polyfills you want to include. 可选:如果你还使用了 jsonp,引入 fetch-jsonp 6. Ravi Kiran demonstrates how to combine powerful new ES6 features (namely generators, Promises and the Fetch API) to create asynchronous APIs in JavaScript. from and fetch support — if I do not find them, then I just load the polyfill for that browser. If you don’t have Fetch, polyfill it, or use Bluebird, Request or Axios, and handle all your promises with await. First of all, Babel requires a runtime to work. But, when there is a totally new feature, like fetch(), Babel doesn't handle that. Donate $5 to cdnjs via Bountysource, Open Collective or Patreon, or contribute on GitHub to make cdnjs sustainable! Twitter Discourse. Fetch helper library for JSON APIs. Babel to the rescue again. As mentioned above, fetch needs Promises to work, so I'm also polyfilling that conditionally as well. I am using babel-preset-env to transpile code down to ES that is supported. x js: js/mylibrary. Libraries We Use. This is very similar to the client-side stack, but it will have more networking code to communicate with the backend. At the bottom in the bundles section, more specifically vendor. (This decision is being reconsidered. /static/ 映射到 /static/ (可以 创建一个静态目录 在你的项目中) 这里有个简单的案例,可以下载看看 sample app - nextgram. Lo dico perché ho visto l’. Instead I recommend using babel-polyfill. Get Started with webpack, Rollup or Parcel. 提示:polyfill指的是“用于实现浏览器不支持原生功能的代码”,比如,现代浏览器应该支持fetch函数,对于不支持的浏览器,网页中引入对应fetch的polyfill后,这个polyfill就给全局的window对象上增加一个fetch函数,让这个网页中的JavaScript可以直接使用fetch函数了. io) Should you use jQuery in 2018?. Thanks to our Thunk middleware, our app will wait until this promise is resolved, and then dispatch the our action object with keys of type and either errors or distributions to our distributions reducer. Using ES6 and ES7 in the Browser, with Babel 6 and Webpack posted in ES6 , Javascript , Meta , React on November 10, 2015 by James K Nelson This guide is part of The Complete Guide to ES6 with Babel 6 series. There's a lot of ways to load polyfills. babelrc or babel. 刚接触 babel 的同学一开始可能都认为在使用了 babel 后就可以无痛的使用 es2015 了,之后被各种 undefined 的报错无情打脸。一句话概括, babel 的编译不会做 polyfill。那么 polyfill 是指什么呢?. babel-polyfill # Babel默认只转换新的JavaScript句法(syntax),而不转换新的API,比如Iterator、Generator、Set、Maps、Proxy、Reflect、Symbol、Promise等全局对象,以及一些定义在全局对象上的方法(比如Object. It's modular, so you can only pick what you need. React为了引入JSX,必须需要引入编译,这又间接促成Babel与webpack的壮大。尤其是Babel, 让我们在很旧的浏览器中使用非常新的语法,甚至一些还没有定案的语法。React从14升级到React 15,强制使用class语法,让这个推了好久的语法糖终于大规模落地。. In browsers that don’t support it, provide a “good enough” polyfill. For example, in my project I have an App component which contains a container which all other components in the app render into. There are all these options. fetch polyfill The fetch() function is a Promise-based mechanism for programmatically making web requests in the browser. A script that updates/adds new functions is called “polyfill”. This is very similar to the client-side stack, but it will have more networking code to communicate with the backend. 11 Closure 2019. json are runnable by typing npm run build or npm run start from the command prompt. In the first, we used sinon. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. 2k(gzipped 27. entry: ['babel-polyfill', 'whatwg-fetch','. Set up NPM build systems using Gulp, Browserify, Jade, and Stylus. If the promise rejects, it throws with the rejection value, so you can deal with it using catch. OK, I Understand. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: