Case Converter

An ultra-lean and fast CLI tool for converting text to various case formats. Built with TypeScript and optimised for performance whilst maintaining readability.

Features

• 5 Case Conversion Types: Sentence case, lowercase, UPPERCASE, Title Case, and tOGGLE cASE
• Multiple Input Methods: Command-line arguments or stdin
• High Performance: Optimised for speed with large text inputs
• Comprehensive Error Handling: Robust handling of edge cases and invalid inputs
• Unicode Support: Works with international characters, emojis, and special symbols
• Zero Dependencies: Lightweight with no external runtime dependencies
• Global Installation: Can be run from any directory after installation

Installation

Global Installation (Recommended)

npm install -g case-converter

Local Installation

npm install case-converter

From Source

git clone https://github.com/Sharma-IT/case-converter.git
cd case-converter
npm install
npm run build
npm link

Usage

Command Line Arguments

# Convert text provided as arguments
case-converter "hello WORLD"
case-converter hello beautiful WORLD

# Show help
case-converter --help
case-converter -h

# Show version
case-converter --version
case-converter -v

Stdin Input

# Pipe text from other commands
echo "hello WORLD" | case-converter

# Read from file
cat myfile.txt | case-converter

# Interactive input (type text and press Ctrl+D)
case-converter

Output Format

Input: hello WORLD

Sentence case: Hello world
lowercase: hello world
UPPERCASE: HELLO WORLD
Title Case: Hello World
tOGGLE cASE: HELLO world

Case Conversion Types

| Type | Description | Example Input | Example Output | |------|-------------|---------------|----------------| | Sentence case | First letter capitalised, rest lowercase | hello WORLD | Hello world | | lowercase | All letters in lowercase | Hello WORLD | hello world | | UPPERCASE | All letters in uppercase | hello world | HELLO WORLD | | Title Case | First letter of each word capitalised | hello world | Hello World | | tOGGLE cASE | Invert the case of each letter | Hello World | hELLO wORLD |

Advanced Examples

Working with Special Characters

case-converter "café naïve"
# Output includes proper handling of accented characters

case-converter "[email protected]"
# Handles email addresses and special characters

case-converter "version-1.2.3"
# Works with version strings and hyphens

Working with Unicode

case-converter "Hello 世界 WORLD"
# Supports mixed scripts and Unicode characters

case-converter "hello 🌍 WORLD!"
# Handles emojis and symbols correctly

Performance with Large Inputs

# The tool efficiently handles large text files
cat large-document.txt | case-converter

# Works with very long strings
case-converter "$(cat /usr/share/dict/words | head -1000 | tr '\n' ' ')"

Development

Prerequisites

• Node.js 14.0.0 or higher
• npm or yarn

Setup

# Clone the repository
git clone https://github.com/Sharma-IT/case-converter.git
cd case-converter

# Install dependencies
npm install

# Build the project
npm run build

# Run tests
npm test

# Run tests with coverage
npm run test:coverage

# Watch mode for development
npm run dev

Project Structure

case-converter/
├── src/
│   ├── types.ts          # TypeScript type definitions
│   ├── converters.ts     # Core case conversion functions
│   ├── cli.ts           # CLI interface and argument parsing
│   ├── index.ts         # Main entry point
│   └── *.test.ts        # Test files
├── dist/                # Compiled JavaScript files
├── coverage/            # Test coverage reports
├── package.json         # Package configuration
├── tsconfig.json        # TypeScript configuration
├── jest.config.js       # Jest test configuration
└── README.md           # This file

Testing

The project follows test-driven development (TDD) principles with comprehensive test coverage:

# Run all tests
npm test

# Run specific test file
npm test -- src/converters.test.ts

# Run tests in watch mode
npm run test:watch

# Generate coverage report
npm run test:coverage

Scripts

| Script | Description | |--------|-------------| | npm run build | Compile TypeScript to JavaScript | | npm test | Run all tests | | npm run test:watch | Run tests in watch mode | | npm run test:coverage | Run tests with coverage report | | npm run dev | Watch mode for development | | npm run lint | TypeScript compilation check | | npm start | Run the CLI tool |

API

Programmatic Usage

You can also use the case converter functions programmatically:

import { 
  toSentenceCase, 
  toLowerCase, 
  toUpperCase, 
  toTitleCase, 
  toToggleCase,
  getCaseConverters 
} from 'case-converter';

// Individual functions
const sentence = toSentenceCase('hello WORLD'); // "Hello world"
const lower = toLowerCase('Hello WORLD');       // "hello world"
const upper = toUpperCase('hello world');       // "HELLO WORLD"
const title = toTitleCase('hello world');       // "Hello World"
const toggle = toToggleCase('Hello World');     // "hELLO wORLD"

// Get all converters
const converters = getCaseConverters();
const results = Object.entries(converters).map(([type, converter]) => ({
  type,
  result: converter('hello WORLD')
}));

Error Handling

The tool provides comprehensive error handling for various scenarios:

• Empty Input: Clear error message when no input is provided
• Invalid Arguments: Helpful usage information for incorrect usage
• Large Inputs: Performance warnings for very large text inputs
• Unicode Edge Cases: Graceful handling of special Unicode characters
• System Errors: Proper error reporting for file system or stdin issues

Performance

• Optimised Algorithms: Efficient string manipulation algorithms
• Memory Management: Minimal memory footprint with proper cleanup
• Large Input Handling: Can process files with millions of characters
• Concurrent Processing: Supports multiple simultaneous conversions

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes following the existing code style
4. Add tests for new functionality
5. Ensure all tests pass (npm test)
6. Commit your changes (git commit -m 'Add amazing feature')
7. Push to the branch (git push origin feature/amazing-feature)
8. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Author

Shubham Sharma

• Email: [email protected]
• GitHub: @Sharma-IT

Changelog

v1.0.0

• Initial release
• Support for 5 case conversion types
• CLI interface with argument and stdin support
• Comprehensive test suite
• Unicode and international character support
• Performance optimisations
• Error handling and edge case management