!Debundle

debundle

This is a tool to decode javascript bundles produced by tools like Webpack and Browserify
into their original, pre-bundled source.


Why would I want to debundle my code?

Reasons vary, but this tool was originally developed to help me with a reverse engineering project.
Needless to say, sifting through minified bundles to try and figure out how a service works isn't
fun and is a lot easier when that bundle is broken into files and those files have semantic names.

Installation

``
npm i -g debundle
`

Running

`bash
$ debundle
Usage: debundle [input file] {OPTIONS}

Options:
--input, -i Bundle to debundle
--output, -o Directory to debundle code into.
--config, -c Configuration file

$ curl https://raw.githubusercontent.com/1egoman/debundle/master/test_bundles/browserify/bundle.js > bundle.js
$ curl https://raw.githubusercontent.com/1egoman/debundle/master/test_bundles/browserify/debundle.config.json > debundle.config.json
$ cat debundle.config.json
{
"type": "browserify",
"knownPaths": {}
}
$ debundle -i bundle.js -o dist/ -c debundle.config.json
$ tree dist/
dist/
├── index.js
└── node_modules
├── number
│   └── index.js
└── uuid
├── index.js
├── lib
│   ├── bytesToUuid.js
│   └── rng.js
├── v1.js
└── v4.js
4 directories, 7 files
`

Configuration

Simple configuration


`
{
"type": "browserify",
"entryPoint": 1,
"knownPaths": {}
}
`

(To debundle a simple Webpack bundle, replace browserify the above configuration with webpack)

A configuration can have a number of flags - they are documented in DOCS.md.

FAQ

$3

No. There a bunch of metadata that's lost when bundling:
- Any custom package.json settings for each node_module and the root package.
- In a webpack bundle, the names of modules aren't in the bundle. By default, debundling will produce
files named after the module id (ie, 1.js) unless manually overridden.
- If your code was minified, the output files from the debundling process will also be minified (ie,
no whitespace, single letter variables, etc). It's up to you to run source through other tools to
make it look nicer.

$3

- Make sure that either when rebundling or running with node that you're using the correct file as
your entrypoint.
- Read through all the configuration options. Some of them have caveats.
- You could have run into an edge case that I haven't seen yet. Feel free to open an issue if you believe that to be the case.

$3

Not officially. However, if a bundle shares the same type module layout as Browserify or Webpack it
may be possible to set the moduleAst
configuration option to point to the location of the modules.

Contributing


- After cloning down the project, run npm install - that should be it.
- Debundler entry point is ./src/index.js (that's how you run it!)
- A bunch of sample bundles are in test_bundles/. A script, test_bundles/run_test.sh can run the
debundler against a given bundle and try to debundle it into dist/. (CI will, as part of running
tests, debundle all the bundles in that folder.)
- Make sure any contribution pass the tests: npm test`

Legal note

Some companies specify in their terms of service that their code cannot be "reverse engineered".
Debundling can definitely (depending on how you're using the code) fall under that umbrella.
Understand what you are doing so you don't break any agreements :smile: