Parcel

这是一个无需配置的构建工具,能够处理
  • the web.
  • JavaScript.
  • CSS.
  • HTML.
  • TypeScript.
  • React.
  • images.
  • SASS.
  • SVG.
  • Vue.
  • libraries.
  • Less.
  • CoffeeScript.
  • Node.
  • Stylus.
  • Pug.
  • Electron.
  • Elm.
  • WebGL.
  • extensions.
  • GraphQL.
  • MDX.
  • XML.

Parcel 将出色的开箱即用的开发体验与可扩展的架构相结合,无论您的项目是雏形阶段还是大规模生产应用阶段,都能从容应对。

快速入门 GitHub
用户包括:

A build tool for the rest of us.

Parcel starts with a great development experience, from starting a new project, to iterating and debugging, and shipping to production. No more fiddling with configuration, or spending hours to keep up with best practices – it just works!

Zero config

只要一个 HTML 文件就能开始。然后添加 <script> 标签。也可以添加 CSS。TypeScript 呢?SASS 呢?图片呢?都没问题。Parcel 开箱即用,让你所想即所得。

Parcel 开箱即支持多种编程语言和文件类型,包括 HTML、CSS 和 JavaScript 等 web 技术,以及图片、字体、视频等静态资源。 当您使用的文档类型没有被默认支持时,Parcel 会为您 自动安装 所有必要的插件和开发依赖项!

开始使用 →
index.html
<html>
  <head>
    <title>My First Parcel App</title>
    <link rel="stylesheet" href="styles.css">
  </head>
  <body>
    <h1>Hello, World!</h1>
    <script type="module" src="app.tsx"></script>
  </body>
</html>

Dev server

Parcel 内置了一个开箱即用的开发服务器。只需运行 parcel index.html 即可开始使用。

需要 HTTPS? 运行 Parcel 时指定 --https 参数即可,它会自动为您生成证书!或者,如果你愿意,也可以使用自己的证书。

Parcel 还内置了 API 代理,有助于模拟生产环境。

了解更多 →

Hot reloading

当您编辑代码时,Parcel 会自动更新浏览器中显示的内容,并且无需重新加载页面!

Parcel 还集成了 React Fast RefreshVue Hot Reloading API ,可在每次更新之间自动保留应用程序的状态。这样,您在编辑代码时就能获得即时反馈,而不会丢失上下文。

了解更多信息 →

Diagnostics

如果您的代码或配置出错,Parcel 会在终端窗口(或命令行)和浏览器中显示 漂亮的诊断信息

每个错误都包含一个带有语法高亮显示的代码框,指向发生错误的确切位置,并提示如何解决该问题。

许多诊断信息甚至还包含一个文档链接,您可以从中了解更多信息。

$ parcel index.html
Server running at http://localhost:1234
🚨 Build failed.

@parcel/core: Cannot resolve 'ract' from './index.js'
/dev/app/index.js:1:19
> 1 | import React from 'ract';
>   |                   ^^^^^^
  2 | 
  3 | function Test() {

@parcel/resolver-default: Cannot find module 'ract'
Did you mean 'react'?

自动针对生产环境进行优化。

Parcel 会自动优化您的整个应用程序,使其适合生产环境。这些优化包括对 JavaScript、CSS 和 HTML 进行 tree-shaking 和精简(minifying),调整图片大小并进行优化,content hashing,自动代码拆分等。

Tree shaking

Parcel supports tree-shaking both ES modules and CommonJS out of the box! It statically analyzes the imports and exports of each module, and removes everything that isn't used.

Tree shaking even works across dynamic import() boundaries, shared bundles, and even across languages! If you use CSS modules, unused classes will be removed automatically.

Learn more →
index.js
import {add} from './math';

console.log(add(2, 3));
math.js
export function add(a, b) {
  return a + b;
}
export function square(a) {
  return a * a;
}

Minification

Parcel includes minifiers for JavaScript, CSS, HTML, and SVG out of the box! Just run parcel build index.html, and your whole application will be built and optimized automatically.

Learn more →

Image optimization

Parcel supports resizing, converting, and optimizing images! Just pass query parameters for the format and size you need when referencing the image file in your HTML, CSS, JavaScript, etc. and Parcel will take care of the conversion and optimization process.

You can even request multiple sizes or formats of the same source image for different devices or browsers!

Learn more →
index.html
<picture>
  <source type="image/webp" srcset="image.jpg?as=webp&width=400, image.jpg?as=webp&width=800 2x">
  <source type="image/jpeg" srcset="image.jpg?width=400, image.jpg?width=800 2x">
  <img src="image.jpg?width=400" width="400">
</picture>

Compression

Compress your app before you deploy using Gzip and Brotli.

Learn more →

Code splitting

When multiple parts of your application depend on the same common modules, they are automatically deduplicated into a separate bundle. This allows commonly used dependencies to be loaded in parallel with your application code and cached separately by the browser!

Code splitting is also supported for CSS. If you import CSS from your JavaScript, a sibling CSS bundle will be produced and loaded in parallel with the JS bundle.

Learn more →
Dashboard Profile React Lodash

Content hashing

dashboard.js react.js dashboard.a96cdf.js

Parcel automatically includes content hashes in the names of all output files. This enables long-term browser caching, because the output is guaranteed not to change unless the name does.

Parcel also resolves all referenced bundles relative to their parent using a manifest in each entry. This means that changes to referenced bundles don't invalidate the cache for their parents as well, and output files can be moved between locations without rebuilding.

Learn more →

Scalable from small websites to massive applications.

Parcel requires zero configuration to get started. But as your application grows and your build requirements become more complex, it's possible to extend Parcel in just about every way.

Simple configuration?!

Configuring Parcel is like a breath of fresh air. .parcelrc is a simple JSON-based config format that uses globs to match your source files to build pipelines. You can extend the default config and add plugins to handle custom file types, or override and extend the defaults.

Learn more →

Extends

Start with the default config, or a community preset.

Transformers

Compile individual source files and extract dependencies.

Resolvers

Resolve a dependency to a file path or virtual module.

Namers

Determine the name of an output file.

Packagers

Combine multiple assets together into a single output file.

Optimizers

Minify, optimize, and transform output files.

Compressors

Compress and encode output files in multiple formats.

Reporters

Receive events on build progress and completion.

.parcelrc
{
  "extends": ["@parcel/config-default"],
  "transformers": {
    "*.svg": ["@parcel/transformer-svg-react"]
  },
  "resolvers": ["@parcel/resolver-glob", "..."],
  "namers": ["@company/parcel-namer", "..."],
  "packagers": {
    "*.{jpg,png}": "parcel-packager-image-sprite"
  },
  "optimizers": {
    "*.js": ["parcel-optimizer-license-headers"]
  },
  "compressors": {
    "*.js": ["...", "@parcel/compressor-gzip"]
  },
  "reporters": ["...", "parcel-reporter-manifest"]
}

Powerful plugins

import {Transformer} from '@parcel/plugin';

export default new Transformer({
  async transform({asset}) {
    let source = await asset.getCode();
    let sourceMap = await asset.getMap();

    let {code, map} = compile(source, sourceMap);
    asset.setCode(code);
    asset.setMap(map);

    return [asset];
  }
});

Parcel has a plugin for everything. In fact, Parcel core is completely language agnostic! From transforming files, to resolving dependencies, to bundling and optimizing – everything is customizable.

Each plugin type has a specific, well defined API designed for its purpose. All objects and methods are fully documented, and include TypeScript definitions for autocomplete and type safety.

As you're developing a plugin, it even hot reloads as you save without needing to re-run your build from scratch! This makes it super fast to debug and iterate. It even works with dependencies in node_modules!

Learn more →

Named pipelines

Want to transform the same types of files in multiple ways in a single build? Create a named pipeline, and use it as a URL scheme in your code.

For example, you could inline the compiled contents of a bundle as text, a data URL, an ArrayBuffer, or anything else! Or if you're building a documentation site, you could import both the generated API docs and source code for a file. The possibilities are endless.

Learn more →
.parcelrc
{
  "extends": "@parcel/config-default",
  "transformers": {
    "buffer:*": ["...", "parcel-transformer-buffer"]
  }
}
App.js
import buffer from 'buffer:./logo.png';

Designed for performance

Parcel's plugin system has been designed from the ground up with performance in mind. Plugins are automatically parallelized across multiple threads, and integrated with Parcel's cache. Any dependencies or configs your plugin uses are automatically tracked and invalidate the build.

Learn more →

API

Integrate Parcel into any existing build system using Parcel's API, which allows you to perform builds programmatically.

Learn more →

Diagnostics

All Parcel plugins use a unified diagnostic format that supports highlighted code frames, rich Markdown formatting, hints, and documentation links.

Learn more →