@esp-labs/validators NPM

@esp-labs/validators

This library provides a clean and extensible way to validate data in your TypeScript/JavaScript applications.

Features

🎯 Strong TypeScript support
🏗️ Hexagonal Architecture design
🧩 Extensible validation system
📝 Comprehensive string validation
🔍 Pattern matching support
⚡ Zero dependencies
📚 Well-documented API
✅ 100% test coverage

Installation

npm install @esp-labs/validators

yarn add @esp-labs/validators

Quick Start

String Validation Example

import { StringValidator } from '@esp-labs/validators';

// Create a validator for an email field
const emailValidator = new StringValidator({
  fieldName: 'email',
  minLength: 5,
  maxLength: 100,
  pattern: /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/
});

try {
  // Validate an email
  emailValidator.validate('user@example.com'); // Returns true if valid
} catch (error) {
  console.error(error.message); // Handles validation errors
}

API Reference

StringValidator

The StringValidator class provides comprehensive string validation capabilities.

Constructor Options

interface StringValidationType {
  fieldName: string;
  minLength?: number;
  maxLength?: number;
  pattern?: RegExp;
}

Option	Type	Description
fieldName	string	Name of the field being validated (used in error messages)
minLength	number	(Optional) Minimum length requirement
maxLength	number	(Optional) Maximum length requirement
pattern	RegExp	(Optional) Regular expression pattern to match

Methods

validate(value: unknown): boolean

Validates the provided value against the configured options.

Returns true if validation passes
Throws ValidationErrorException if validation fails

Error Handling

The library uses custom ValidationErrorException for all validation errors. Each error includes a descriptive message indicating the specific validation failure.

try {
  validator.validate('test');
} catch (error) {
  if (error instanceof ValidationErrorException) {
    console.error(error.message);
  }
}

Project Structure

## Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

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

## Testing

The project maintains 100% test coverage. To run tests:

```bash
npm test

For coverage report: