Wakaru

Wakaru is the Javascript decompiler for modern frontend. It brings back the original code from a bundled and transpiled source.

• 🔪📦 Unpacks bundled JavaScript into separated modules from webpack and browserify.
• ⛏️📜 Unminifies transpiled code from Terser, Babel, SWC, and TypeScript.
• ✨📚 Detects and restores downgraded syntaxes (even with helpers!). See the list.
• 🧪🛡️ All cases are protected by tests. All code is written in TypeScript.

Demo

See live demo for detailed examples.

Features

Unminify

Converts transpiled code back to its readable form and restores downgraded syntaxes.

Supports the following transpilers:

• Terser
• Babel
• SWC
• TypeScript

Read the documentation for more information.

Unpacker

Converts bundled JavaScript into separated modules

Supports the following bundlers:

• webpack
• browserify

Try it out

Test the tool and see it in action at Playground.

🖥 Using the CLI

Interactive mode

By default, the CLI will run in interactive mode and guide you through the process.
You can also pass options to skip some steps in the interactive mode.

npx @wakaru/cli
# or
pnpm dlx @wakaru/cli

Options

Run npx @wakaru/cli --help to see the full list of options.

Option	Default	Description
--output	"out"	Output directory
--force	false	Force overwrite output directory
--concurrency	1	Specific the number of concurrent tasks
--perf	false	Show performance metrics
--perf-output		Performance metrics output directory

--concurrency can be used to speed up the process. But please aware that the process might OOM if the input file is too large.

Non-interactive mode

If you want to run the CLI in non-interactive mode, you can specify the feature by passing the feature name as the first argument.

unpacker and unminify will run only the corresponding feature.
all will run both unpacker and unminify sequentially.

npx @wakaru/cli all      <files...> [options]
npx @wakaru/cli unpacker <files...> [options]
npx @wakaru/cli unminify <files...> [options]

These options are only available in all mode.

Option	Default	Description
--unpacker-output	"out/unpack"	Override unpacker output directory
--unminify-output	"out/unminify"	Override unminify output directory

When running a single feature (either unpacker or unminify), the CLI will only uses the path specified in the --output option. This means that, unlike in the all mode where subdirectories (out/unpack and out/unminify) are automatically created within the output directory, in single feature mode, the output files are placed directly in the specified --output directory without any additional subdirectories.

📦 Using the API

npm install @wakaru/unpacker @wakaru/unminify
# or
pnpm install @wakaru/unpacker @wakaru/unminify
# or
yarn add @wakaru/unpacker @wakaru/unminify

Click to expand

@wakaru/unpacker

import { unpack } from '@wakaru/unpacker';

const { modules, moduleIdMapping } = await unpack(sourceCode);
for (const mod of modules) {
  const filename = moduleIdMapping[mod.id] ?? `module-${mod.id}.js`;
  fs.writeFileSync(outputPath, mod.code, 'utf-8');
}

@wakaru/unminify

import { runDefaultTransformationRules, runTransformationRules } from '@wakaru/unminify';

const file = {
  source: '...', // source code
  path: '...',   // path to the file, used for advanced usecases. Can be empty.
}
// This function will apply all rules that are enabled by default.
const { code } = await runDefaultTransformationRules(file);

// You can also specify the rules to apply. Order matters.
const rules = [
  'un-esm',
  ...
]
const { code } = await runTransformationRules(file, rules);

You can check all the rules at /unminify/src/transformations/index.ts.

Please aware that this project is still in early development. The API might change in the future.

And the bundle size of these packages are huge. It might be reduced in the future. Use with caution on the browser (Yes, like the playground, it can run on the browser ✨).

Legal Disclaimer

Usage of wakaru for attacking targets without prior mutual consent is illegal. It is the end user's responsibility to obey all applicable local, state and federal laws. Developers assume no liability and are not responsible for any misuse or damage caused by this program.

License

MIT