# invisi-data

> Invisible data at ease

Latest version **1.2.0** (published 2025-09-03) · MIT license · 0 weekly downloads

## Install

```sh
npm install invisi-data
pnpm add invisi-data
yarn add invisi-data
bun add invisi-data
```

## Health

**Score 60/100 (C)** — status: stable.

Positive: has types; esm support; no vulnerabilities; high quality score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 1.2.0 |
| Published | 2025-09-03 |
| First published | 2024-12-10 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 21 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 1 |
| Author | kobenguyent |
| Maintainers | thanh.nguyen |
| Keywords | invisible, mask, hide, obsfucate |

## Links

- npm: https://www.npmjs.com/package/invisi-data
- Repository: https://github.com/kobenguyent/invisi-data
- Homepage: https://github.com/kobenguyent/invisi-data#readme
- Issues: https://github.com/kobenguyent/invisi-data/issues
- npm.io page: https://npm.io/package/invisi-data

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## Recent versions

- 1.2.0 (latest) — 2025-09-03
- 1.1.2 — 2024-12-10
- 1.1.1 — 2024-12-10
- 1.1.0 — 2024-12-10
- 1.0.0 — 2024-12-10

## README

# `invisi-data` 

[![npm version](https://badge.fury.io/js/invisi-data.svg)](https://badge.fury.io/js/invisi-data)
[![MIT License](https://img.shields.io/badge/License-MIT-green.svg)](https://choosealicense.com/licenses/mit/)
[![Node.js CI](https://github.com/kobenguyent/invisi-data/actions/workflows/npm-publish.yml/badge.svg)](https://github.com/kobenguyent/invisi-data/actions/workflows/npm-publish.yml)

A lightweight, efficient utility for identifying and masking sensitive information in strings. Perfect for logging, debugging, and data sanitization without exposing sensitive data like API keys, tokens, passwords, and other credentials.

## ✨ Features

- **🎯 Smart Pattern Recognition**: Uses predefined regex patterns to detect various types of sensitive data
- **⚡ High Performance**: Optimized for handling large strings efficiently
- **🔧 Customizable**: Support for custom masking patterns alongside predefined ones  
- **🛡️ Type-Safe**: Full TypeScript support with comprehensive type definitions
- **📦 Zero Dependencies**: Lightweight with no external dependencies
- **🌐 Universal**: Works in Node.js, browsers, and other JavaScript environments
- **🔗 Multiple Formats**: Supports both ES modules and CommonJS

---

## 📦 Installation

```bash
npm install invisi-data
```

---

## 🚀 Quick Start

### ES Modules (Recommended)
```javascript
import { maskSensitiveData } from 'invisi-data';

const input = JSON.stringify({
    Authorization: "Bearer abc123token",
    "api-key": "sk_live_sensitive_key_123",
    password: "supersecret123"
});

const masked = maskSensitiveData(input);
console.log(masked);
// Output: {"Authorization": "Bearer ****", "api-key": "****", "password": "****"}
```

### CommonJS
```javascript
const { maskSensitiveData } = require('invisi-data');

const logData = '{"Authorization": "Bearer jwt_token_here", "user": {"password": "userpass"}}';
const sanitized = maskSensitiveData(logData);
console.log(sanitized);
// Output: {"Authorization": "Bearer ****", "user": {"password": "****"}}
```

---

## 📚 API Reference

### `maskSensitiveData(input, customPatterns?)`

Masks sensitive data in the provided string using predefined and custom patterns.

#### Parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `input` | `string` | ✅ | The input string containing potential sensitive data |
| `customPatterns` | `MaskingPattern[]` | ❌ | Optional array of custom masking patterns |

#### Returns

- **Type**: `string`
- **Description**: A new string with sensitive data replaced by `****`

#### Throws

- `InvalidInputError`: When input is not a valid string or is empty/whitespace only

### Type Definitions

```typescript
type MaskingPattern = {
  name: string;        // Human-readable pattern name
  regex: RegExp;       // Regular expression to match sensitive data
  mask: string;        // Replacement string for matches
};

class InvalidInputError extends Error {
  name: 'InvalidInputError';
}
```

---

## 🔍 Supported Sensitive Data Patterns

The library automatically detects and masks the following types of sensitive information:

| Pattern Type | Example Match | Masked Result |
|-------------|---------------|---------------|
| **Authorization Bearer** | `"Authorization": "Bearer abc123"` | `"Authorization": "Bearer ****"` |
| **cURL Authorization** | `"Authorization Bearer abc123"` | `"Authorization Bearer ****"` |
| **API Key** | `"api-key": "sk_live_123"` | `"api-key": "****"` |
| **Access Token** | `"access_token": "token123"` | `"access-token": "****"` |
| **Refresh Token** | `"refresh-token": "refresh123"` | `"refresh-token": "****"` |
| **Client ID** | `"client_id": "client123"` | `"client-id": "****"` |
| **ID Token** | `"id-token": "id123"` | `"id-token": "****"` |
| **Client Secret** | `"client_secret": "secret123"` | `"client-secret": "****"` |
| **Generic Token** | `"token": "abc123"` | `"token": "****"` |
| **Password** | `"password": "mypassword"` | `"password": "****"` |
| **Basic Auth** | `"Authorization": "Basic dXNlcjpwYXNz"` | `"Authorization": "Basic ****"` |

**Note**: All patterns are case-insensitive and support both hyphen (`-`) and underscore (`_`) variations.

---

## 🎨 Advanced Usage

### Custom Patterns

Create your own masking patterns for domain-specific sensitive data:

```javascript
import { maskSensitiveData, createPattern } from 'invisi-data';

// Create custom patterns
const customPatterns = [
    createPattern(
        'Database Password',
        /"db_password"\s*:\s*"([^"]+)"/gi,
        '"db_password": "****"'
    ),
    createPattern(
        'SSH Private Key',
        /"ssh_key"\s*:\s*"([^"]+)"/gi,
        '"ssh_key": "****"'
    )
];

const config = JSON.stringify({
    database: {
        host: "localhost",
        db_password: "super_secret_db_pass"
    },
    deployment: {
        ssh_key: "-----BEGIN PRIVATE KEY-----\nMIIEvQ...",
        api_key: "prod_api_key_123"
    }
});

const masked = maskSensitiveData(config, customPatterns);
console.log(masked);
```

### Real-World Scenarios

#### HTTP Request Logging
```javascript
const httpLog = `POST /api/auth - Headers: {"Authorization": "Bearer eyJhbGci...", "Content-Type": "application/json"} - Body: {"username": "user", "password": "secret123"}`;

const sanitizedLog = maskSensitiveData(httpLog);
console.log(sanitizedLog);
// Output: POST /api/auth - Headers: {"Authorization": "Bearer ****", "Content-Type": "application/json"} - Body: {"username": "user", "password": "****"}
```

#### Configuration File Sanitization
```javascript
const appConfig = {
    server: { port: 3000, host: "localhost" },
    auth: {
        "client-secret": "oauth_client_secret_xyz",
        "api-key": "prod_api_key_abc123"
    },
    database: {
        url: "postgres://localhost:5432/myapp",
        password: "db_password_456"
    }
};

const configString = JSON.stringify(appConfig);
const maskedConfig = maskSensitiveData(configString);
const parsedConfig = JSON.parse(maskedConfig);

console.log(parsedConfig);
// Sensitive values are now masked while preserving structure
```

#### Error Logging
```javascript
function logError(error, context) {
    const errorInfo = {
        message: error.message,
        stack: error.stack,
        context: context  // May contain sensitive data
    };
    
    // Safely log without exposing sensitive information
    console.error(maskSensitiveData(JSON.stringify(errorInfo)));
}
```

---

## ⚡ Performance Characteristics

- **Memory**: Minimal memory footprint with pre-compiled regex patterns
- **Speed**: Optimized for large strings (tested with 1MB+ inputs)
- **Scalability**: Linear time complexity O(n) where n is input string length
- **Efficiency**: Single-pass string processing for all patterns

### Benchmarks
- **Small strings** (< 1KB): ~0.1ms processing time
- **Medium strings** (1KB - 100KB): ~1-10ms processing time  
- **Large strings** (100KB - 1MB): ~10-100ms processing time

---

## 🛠️ Development

### Building the Project
```bash
npm run buildcjs    # Build CommonJS version
```

### Running Tests
```bash
npm test           # Run all tests
npm run test:basic # Run basic functionality tests only
npm run test:extended # Run extended/edge case tests only
```

### Project Structure
```
invisi-data/
├── index.js           # Main module (ES6)
├── patterns.js        # Pattern definitions
├── index.cjs          # CommonJS build output
├── types.d.ts         # TypeScript definitions
├── index_test.js      # Basic test suite
└── test/
    └── extended-tests.js # Extended test coverage
```

---

## 🤝 Contributing

We welcome contributions! Here's how you can help:

### Ways to Contribute
- 🐛 **Report Bugs**: Open an issue with reproduction steps
- 💡 **Suggest Features**: Propose new patterns or functionality
- 📝 **Improve Documentation**: Help make our docs clearer
- 🧪 **Add Tests**: Increase test coverage for edge cases
- 💻 **Submit Code**: Fix bugs or implement new features

### Development Setup
1. Fork and clone the repository
2. Run `npm install` to install dependencies
3. Make your changes
4. Run `npm test` to ensure all tests pass
5. Run `npm run buildcjs` to verify build works
6. Submit a pull request with a clear description

### Adding New Patterns
When adding new sensitive data patterns:

1. Add the pattern to `patterns.js`
2. Update `types.d.ts` if needed
3. Add comprehensive tests in `test/extended-tests.js`
4. Update this README with pattern documentation

---

## 🔒 Security Considerations

- **False Negatives**: Some sensitive data might not match predefined patterns
- **False Positives**: Non-sensitive data might occasionally be masked
- **Custom Patterns**: Always test custom patterns thoroughly
- **Data Validation**: The library masks but doesn't validate data formats
- **Encoding**: Assumes UTF-8 string encoding

---

## 📝 Changelog

### v1.2.0 (Current)
- ✨ Added modular pattern system with `patterns.js`
- 🛡️ Improved error handling with `InvalidInputError` class
- 🧪 Comprehensive test suite with 40+ test cases
- 📚 Enhanced documentation and examples
- ⚡ Performance optimizations for large strings
- 🔧 Better regex patterns supporting unicode and special characters

### v1.1.2 (Previous)
- Basic masking functionality
- Limited test coverage
- Simple error handling

---

## 📄 License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

---

## 🙏 Acknowledgments

- Thanks to all contributors who help improve this library
- Inspired by the need for better sensitive data handling in logging systems
- Built with ❤️ for the JavaScript community

---

## 📞 Support

- 🐛 **Issues**: [GitHub Issues](https://github.com/kobenguyent/invisi-data/issues)
- 📖 **Documentation**: This README and inline code comments
- 💬 **Discussions**: [GitHub Discussions](https://github.com/kobenguyent/invisi-data/discussions)

---

<div align="center">

**Made with ❤️ by [kobenguyent](https://github.com/kobenguyent)**

⭐ Star this repo if you find it helpful!

</div>

---
_Source: https://npm.io/package/invisi-data · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._