Sourcemap Extractor

A Node.js command-line tool to extract source files from JavaScript source maps.

Installation

Global Installation

npm install -g sourcemap-extractor

Local Installation

npm install sourcemap-extractor

Usage

Command Line (Global)

# Basic usage
sourcemap-extractor https://example.com/app.js.map
# Specify output file
sourcemap-extractor -o my-sources.zip https://example.com/app.js.map
# Interactive mode (prompts for URL)
sourcemap-extractor

Command Line Options

• -o, --output <path> - Specify output ZIP file path (default: extracted_sources.zip)
• -h, --help - Show help message
• -v, --version - Show version

Programmatic Usage

const{ extractSourceMap }=require('sourcemap-extractor');asyncfunctionmain(){awaitextractSourceMap('https://example.com/app.js.map','output.zip');}

Features

• 🗂️ Preserves folder structure - Creates proper directory hierarchy in the ZIP file
• 📦 Handles multiple source types - Works with webpack, rollup, vite, and other bundlers
• 🔍 Detects package.json - Automatically identifies and reports package.json files
• 🌐 Fetches missing sources - Attempts to download source files not embedded in the map
• 🛡️ Error handling - Gracefully handles missing or inaccessible files
• ⚡ Fast extraction - Efficiently processes large source maps

Examples

Extract from a webpack bundle

sourcemap-extractor https://app.example.com/static/js/main.abc123.js.map

Extract to specific location

sourcemap-extractor -o ./extracted/sources.zip https://example.com/bundle.js.map

Use in a script

const{ extractSourceMap }=require('sourcemap-extractor');(async()=>{try{awaitextractSourceMap('https://example.com/app.js.map','extracted-sources.zip');console.log('Extraction completed!');}catch(error){console.error('Extraction failed:',error);}})();

Output Structure

The tool preserves the original folder structure:

extracted_sources.zip/
├── src/
│ ├── components/
│ │ ├── Button.js
│ │ └── Modal.js
│ ├── utils/
│ │ └── helpers.js
│ └── index.js
├── node_modules/
│ └── some-package/
│ └── index.js
└── package.json

Path Handling

The tool intelligently handles various path formats:

• webpack://./src/file.js → src/file.js
• ./utils/helper.js → utils/helper.js
• ../shared/constants.js → parent/shared/constants.js
• Illegal filesystem characters are replaced with underscores

Requirements

• Node.js 12.0.0 or higher
• Internet connection (for fetching source maps and missing files)

License

MIT

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request