prepack README

The project's README from github.com/facebookarchive/prepack. As one markdown file: README.md.

Prepack Circle CI

Prepack is a partial evaluator for JavaScript. Prepack rewrites a JavaScript bundle, resulting in JavaScript code that executes more efficiently. For initialization-heavy code, Prepack works best in an environment where JavaScript parsing is effectively cached.

See the official prepack.io website for an introduction and an interactive REPL playground.

Status

We, the Prepack team at Facebook, have temporarily set down work on Prepack including the React compiler project. You won't see many Prepack PRs while we are currently prioritizing some other projects.

How to use Prepack

Install the CLI via npm,

$ npm install -g prepack

Or if you prefer yarn, make sure you get yarn first,

$ npm install -g yarn

and then install the Prepack CLI via yarn:

$ yarn global add prepack

You may need to prepend (pun intended!) the command with sudo in some cases.

Let the party begin

To compile a file and print the output to the console:

$ prepack script.js

If you want to compile a file and output to another file:

$ prepack script.js --out script-processed.js

Detailed instructions and the API can be found at Prepack CLI: Getting Started

Plugins to other tools

The following are a few plugins to other tools. They have been created and are maintained separately from Prepack itself. If you run into any issues with those plugins, please ask the plugin maintainers for support.

Test Results and Code Coverage

How to get the code

  1. Clone repository and make it your current directory.
  2. git submodule init
  3. git submodule update --init
  4. Get yarn and node, then do yarn

Note: For development work you really need yarn, as many scripts require it.

How to build, lint, type check

  1. Get the code
  2. yarn build
    You can later run yarn watch in the background to just compile changed files on the fly.
  3. yarn lint
  4. yarn flow

How to run tests

  1. Get the code
  2. Make sure the code is built, either by running yarn build or yarn watch
  3. yarn test

You can run individual test suites as follows:

How to run the interpreter

  1. Get the code
  2. Make sure the code is built, either by running yarn build or yarn watch
  3. yarn repl
    This starts an interactive interpreter session.

How to run Prepack

  1. Get the code

  2. Make sure the code is built, either by running yarn build or yarn watch.

  3. Have a JavaScript file handy that you want to prepack, for example:
    echo "function hello() { return 'hello'; } function world() { return 'world'; } s = hello() + ' ' + world();" >/tmp/sample.js

  4. cat /tmp/sample.js | yarn prepack-cli
    Try --help for more options.

How to validate changes

Instead of building, linting, type checking, testing separately, the following does everything together:
yarn validate

How to edit the website

The content for prepack.io resides in the website directory of this repository. To make changes, submit a pull request, just like for any code changes.

In order to run the website locally at localhost:8000:

  1. Build prepack into the website: yarn build && mv prepack.min.js website/js
  2. Run python -m SimpleHTTPServer (Python 2) or python -m http.server (Python 3) from the website/ directory

How to contribute

To read more about the project, check out this suggested reading wiki

For more information about contributing pull requests and issues, see our Contribution Guidelines.

License

Prepack is BSD-licensed. We also provide an additional patent grant.

prepack (facebookarchive/prepack)

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Prepack
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这是什么？Prepack 是一个面向 JavaScript 的部分求值器，它会把 JS 打包文件改写成执行效率更高的代码，对初始化逻辑较多的代码尤其有用。
这是编译器还是运行时库？它是一个命令行编译工具，你对 JS 文件运行它，即可生成经过优化的输出文件；此外还为 Rollup、Webpack、Parcel、VS Code 和 Babel 提供了单独的插件。
我该如何在自己的代码上运行它？通过 npm 或 yarn 安装命令行工具，然后用 'prepack-cli' 处理一个 JS 文件，将优化后的输出打印到控制台，或写入另一个文件。
这个项目还在继续开发吗？不在了。Facebook Prepack 团队已暂停该项目的工作，相关的 React 编译器工作也一并暂停，因此新的 PR 或修复应该很少。
我能在 Windows 和 Mac 上使用它，而不只是 Linux 吗？可以。它是一个 Node.js 命令行工具，没有操作系统方面的特殊要求，只要环境中可用 Node 6.1+，就能在 Windows、macOS 和 Linux 上运行。
不安装任何东西，我能试用 Prepack 吗？可以。官方网站 prepack.io 提供了交互式 REPL 演示环境，可以直接在浏览器中体验优化器。
Prepack 的输出可靠吗？其符合性通过 test262 测试套件和一个序列化器测试套件进行检查，但 README 指出并非所有 test262 用例都已通过，因此正确性仍在持续改进中。
Prepack 能与我现有的构建流程配合使用吗？可以。目前有单独维护的 Rollup、Webpack 和 Parcel 插件，还有一个 Visual Studio Code 扩展，以及一个用于 Flow-to-Prepack 模型注解的 Babel 插件。
What are similar projects?typescript-go, closure-compiler, YarnPrism, tools, pkg, tsx, svgr, critical
Which topics is it in?vscode-extension, webpack, optimization, compiler, bsd, deprecated, performance, npm, tool, nodejs, library, javascript
Creator
facebookarchive
Size
18.6 MB
Stars
14.1K
Updated
CommitJan 21Releasev0.2.54Oct 08
Age
10y
Commits · 90 Days