@elpandev/validator

A powerful TypeScript validation library for complex payloads with nested objects, arrays, and multiple validation rules. Perfect for API request validation, form data validation, and complex data structure validation.

Features

• ✅ Nested Object Validation: Validate deeply nested objects with ease
• ✅ Array Validation: Support for validating arrays and array elements
• ✅ Multiple Rules: Apply multiple validation rules to single fields
• ✅ Custom Messages: Customizable error messages for each rule
• ✅ TypeScript First: Full TypeScript support with detailed type definitions
• ✅ Flexible Rules: Support for simple values, objects, and arrays in the same schema
• ✅ Bail Strategy: Optional early exit on first validation failure

Key Benefits

• Enterprise Ready: Built for complex validation scenarios with type safety
• Developer Friendly: Intuitive API with excellent TypeScript support
• Highly Extensible: Easy to add custom validation rules
• Performance Optimized: Efficient validation with minimal overhead
• Comprehensive: Handles all common validation scenarios and edge cases

Installation

npm i @elpandev/validator

Quick Start

import { validate_payload, required, email, min } from '@elpandev/validator'

const payload = {
  name: 'John',
  email: '[email protected]',
  age: 25
}

const rules = {
  name: { required },
  email: { required, email },
  age: { required, min: min(18) }
}

const errors = validate_payload({ payload, rules })

// errors will be an empty object if validation passes
// or contain error messages for failed validations

Usage

import { array, integer, IPMessages, IPRules, max, min, required, some, validate_payload } from '@elpandev/validator'

const payload = {
  id: 987,
  status: 'active',
  info: {
    level: 3,
    tags: ['new', 'urgent']
  },
  preferences: null,
  meta: ['1', 1],
  labels: []
}

const rules = {
  id: { required, integer, min: min(1), max: max(100) },
  status: { required, some: some(['active', 'inactive']) },
  info: {
    level: { required: integer, max: max(10) },
    tags: [
      { required, array, min: min(2) },
      { required, some: some(['new', 'old']) }
    ]
  },
  preferences: { required },
  meta: [ {}, { required, integer } ],
  labels: [ { required, array, min: min(1) } ],
}

const messages = {
  id: { max: 'id max' },
  preferences: { required: 'preferences required' },
  info: { tags: [ {}, { some: 'info.tags some' } ] },
  meta: [ {}, { integer: 'meta integer' } ],
}

const errors = validate_payload({ payload, rules, messages })

// {
//   id: { max: 'id max' },
//   info: { tags: { '1': { some: 'info.tags some' } } },
//   preferences: { required: 'preferences required' },
//   meta: { '0': { integer: 'meta integer' } },
//   labels: { min: 'min' }
// }

Available Validation Rules

• required - Field must be present and not empty
• email - Valid email format
• integer - Integer number validation
• numeric - Numeric value validation
• min / max - Minimum and maximum value constraints
• min_length / max_length - String length constraints
• array - Array type validation
• some - Value must be one of the allowed values
• string - String type validation
• boolean - Boolean type validation
• And many more...

TypeScript Support

Full TypeScript support with comprehensive type definitions for:

• Validation rules structure
• Error messages format
• Nested object validation
• Array validation patterns

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - feel free to use in commercial projects.

Keywords: validation, validator, typescript, payload, form-validation, api-validation, data-validation, schema-validation, nested-validation, array-validation