@decompiler/core

Production-grade reverse engineering toolkit — reconstructs readable, structured source approximations from minified JavaScript, transpiled output, or bytecode artifacts.

Features

• AST-based decompilation — fault-tolerant JS parsing via Acorn + acorn-loose
• Code beautification — configurable reformatting with js-beautify + escodegen
• Symbol renaming — heuristic rename of mangled identifiers to semantic placeholders
• Pluggable parsers & transformers — extend by adding one file per format
• CLI interface — decompiler -i file.min.js -o recovered.js
• Structured logging — JSON or pretty-print via Winston
• Jest test suite with coverage thresholds enforced

Quick Start

npm install
npm test
node src/cli/index.js --input fixtures/input/sample.min.js --output fixtures/output/result.js

CLI Usage

Usage: decompiler [options]

Options:
  -i, --input <file>        Input compiled/minified file (required)
  -o, --output <file>       Output path (omit for stdout)
  -p, --parser <name>       javascript | bytecode  [default: javascript]
  -t, --transformer <name>  beautify | rename | full  [default: full]
  -l, --log-level <level>   error | warn | info | debug  [default: info]
  -f, --format <fmt>        pretty | json  [default: pretty]
  -V, --version             Print version
  -h, --help                Show help

Examples

# Decompile a minified bundle
decompiler -i dist/bundle.min.js -o src-recovered/bundle.js

# Beautify only (skip rename heuristics)
decompiler -i lib/util.js -o lib/util.pretty.js --transformer beautify

# Emit raw JSON AST
decompiler -i app.min.js --format json

# Debug logging
decompiler -i file.js --log-level debug

Project Structure

src/
├── index.js                 Public API entry point
├── cli/index.js             Commander-based CLI
├── core/
│   ├── decompiler.js        Orchestration engine
│   └── pipeline.js          Composable transform runner
├── parsers/
│   ├── index.js             Parser registry
│   ├── javascript.js        Acorn fault-tolerant JS parser
│   └── bytecode.js          Bytecode stub (extend here)
├── transformers/
│   ├── index.js             Transformer registry + generator
│   ├── beautifier.js        escodegen + js-beautify
│   └── renamer.js           Heuristic identifier renaming
└── utils/
    ├── logger.js            Winston logger factory
    ├── fileHandler.js       Safe file I/O
    └── validator.js         Input validation
tests/            Mirror of src/ — one test file per module
fixtures/
├── input/sample.min.js      Bundled minified fixture
└── output/                  Git-ignored decompilation output

npm Scripts

| Command | Purpose | |-----------------------|--------------------------------------------------| | npm start | Run CLI (append -- -i file.js for args) | | npm test | Run Jest suite | | npm run test:coverage | Coverage report (thresholds enforced) | | npm run lint | ESLint (zero warnings) | | npm run lint:fix | Auto-fix lint violations | | npm run build | Lint + test gate (CI entry point) |

Extending the Pipeline

Add a parser — create src/parsers/myformat.js:

'use strict';
function parse(source, opts) { /* return ESTree AST */ }
module.exports = { name: 'myformat', parse };

Register in src/parsers/index.js.

Add a transformer — create src/transformers/mytransform.js:

'use strict';
function transform(ast, opts) { /* return AST */ }
module.exports = { name: 'mytransform', transform };

Register in src/transformers/index.js.

License

MIT