Data Validation Library

A lightweight JavaScript library for data validation, allowing you to define and apply validation rules to your data objects.

Installation

You can install the Data Validation Library via npm:

npm install data-validation-library

Usage

const { Validator, validators } = require('data-validation-library');

// Create a new instance of the Validator class
const validator = new Validator();

// Add validation rules for your fields
validator.addRule('username', 'string', { minLength: 3, maxLength: 20, message: 'Invalid username' });
validator.addRule('age', 'number', { min: 18, max: 100, message: 'Age must be between 18 and 100' });

// Define your data object
const data = {
  username: 'john_doe',
  age: 25
};

// Validate the data
const errors = validator.validate(data);

if (Object.keys(errors).length === 0) {
  console.log('Data is valid!');
} else {
  console.error('Validation errors:', errors);
}

API

Validator Class

constructor()

Creates a new instance of the Validator class.

addRule(fieldName, type, options)

Adds a validation rule for a field.

• fieldName (string): The name of the field to validate.
• type (string): The data type to validate (e.g., 'string', 'number', 'boolean').
• options (object, optional): Additional options for the validation rule, such as minimum length, maximum length, etc.

validate(data)

Validates a data object against the defined validation rules.

• data (object): The data object to validate.

Returns an object containing validation errors, where the keys are the field names and the values are the error messages.

validators Object

Contains built-in validators for common data types:

• string(value, options)
• number(value, options)
• boolean(value, options)

License

This library is licensed under the MIT License.