Parcel 打包示例(React HelloWorld)

2019-11-19 14:31:13

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Parcel 打包特点

极速打包时间

Parcel 使用 worker 进程去启用多核编译。同时有文件系统缓存，即使在重启构建后也能快速再编译。

将你所有的资源打包

Parcel 具备开箱即用的对 JS, CSS, HTML, 文件及更多的支持，而且不需要插件。

自动转换

如若有需要，Babel, PostCSS, 和PostHTML甚至 node_modules 包会被用于自动转换代码.

配置代码分拆

使用动态 import() 语法, Parcel 将你的输出文件束(bundles)分拆，因此你只需要在初次加载时加载你所需要的代码。

热模块替换

Parcel 无需配置，在开发环境的时候会自动在浏览器内随着你的代码更改而去更新模块。

友好的错误日志

当遇到错误时，Parcel 会输出语法高亮的代码片段，帮助你定位问题。

使用 Parcel 打包的 React HelloWorld 应用。GitHub 地址: https://github.com/justjavac/parcel-example/tree/master/react-helloworld

0. 新建目录

mkdir react-helloworldcd react-helloworld

1. 初始化 npm

yarn init -y

或

npm init -y

此时会创建要给 package.json 文件，文件内容：

{ "name": "parcel-example-react-helloworld", "version": "1.0.0", "description": "", "main": "index.js", "scripts": {  "test": "echo /"Error: no test specified/" && exit 1" }, "keywords": [], "author": "", "license": "ISC"}

2. 添加 React

yarn：

yarn add react react-dom

npm:

npm install react react-dom --save

package.json 文件内容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",- "license": "ISC"+ "license": "ISC",+ "dependencies": {+  "react": "^16.2.0",+  "react-dom": "^16.2.0"+ } }

3. 添加 Babel

新建 .babelrc 文件

touch .babelrc

输入内容：

{ "presets": ["react"]}

添加 babel-preset-react：

yarn：

yarn add babel-preset-react -D

npm:

npm install babel-preset-react --D

此时 package.json 文件内容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"-  }+  },+  "devDependencies": {+   "babel-preset-react": "^6.24.1"+  } }

5. 添加 Parcel

yarn：

yarn add parcel-bundler -D

npm:

npm install parcel-bundler --D

此时 package.json 文件内容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"  },  "devDependencies": {-   "babel-preset-react": "^6.24.1"+   "babel-preset-react": "^6.24.1",+   "parcel-bundler": "^1.0.3"    } }

6. 新建 index.html 文件

内容

<html><body>  <div id="root"></div>  <script src="./index.js"></script></body></html>

7. 新建 index.js 文件

import React from "react";import ReactDOM from "react-dom";const App = () => { return <h1>Hello World!</h1>;};ReactDOM.render(<App />, document.getElementById("root"));

8. 添加打包命令

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {-  "test": "echo /"Error: no test specified/" && exit 1"+  "start": "parcel index.html"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"  },  "devDependencies": {    "babel-preset-react": "^6.24.1"    "babel-preset-react": "^6.24.1",    "parcel-bundler": "^1.0.3"    } }

9. 完成

运行