Flex Validator

A flexible schema-based validation library for JavaScript and TypeScript.

Features

• Schema-based validation: Define validation rules using a simple and intuitive schema object.
• Type-safe: Written in TypeScript for robust type checking and autocompletion.
• Flexible: Supports validation of nested objects, arrays, and primitive types.
• Extensible: Easily extendable with custom validation logic.
• Comprehensive validation options:
  • Required fields
  • String patterns (regex)
  • Enums
  • Number ranges (min/max values)
  • Array length constraints (min/max length)

Installation

npm install flex-validator

Usage

Basic Usage

To use Flex Validator, you need to define a validation schema and then use the isValid function to validate your data against that schema.

import { isValid, ObjectValidationScheme } from 'flex-validator';

const schema: ObjectValidationScheme = {
  name: { type: 'string', required: true },
  age: { type: 'number', required: true, minValue: 18 },
  email: { type: 'string', required: true, regex: /^[^\s@]+@[^\s@]+\.[^\s@]+$/ },
};

const data = {
  name: 'John Doe',
  age: 30,
  email: '[email protected]',
};

if (isValid(data, schema)) {
  console.log('Validation successful!');
} else {
  console.log('Validation failed!');
}

Nested Objects

You can validate nested objects by defining an objectScheme within your schema.

import { isValid, ObjectValidationScheme } from 'flex-validator';

const schema: ObjectValidationScheme = {
  user: {
    type: 'object',
    required: true,
    objectScheme: {
      firstName: { type: 'string', required: true },
      lastName: { type: 'string', required: true },
    },
  },
  address: {
    type: 'object',
    required: true,
    objectScheme: {
      street: { type: 'string', required: true },
      city: { type: 'string', required: true },
      zipCode: { type: 'string', required: true, regex: /^\d{5}$/ },
    },
  },
};

const data = {
  user: {
    firstName: 'John',
    lastName: 'Doe',
  },
  address: {
    street: '123 Main St',
    city: 'Anytown',
    zipCode: '12345',
  },
};

if (isValid(data, schema)) {
  console.log('Validation successful!');
} else {
  console.log('Validation failed!');
}

Arrays

You can validate arrays by setting the isArray property to true.

import { isValid, ObjectValidationScheme } from 'flex-validator';

const schema: ObjectValidationScheme = {
  tags: {
    type: 'string',
    isArray: true,
    minLength: 1,
    maxLength: 5,
  },
  users: {
    type: 'object',
    isArray: true,
    objectScheme: {
      name: { type: 'string', required: true },
      email: { type: 'string', required: true, regex: /^[^\s@]+@[^\s@]+\.[^\s@]+$/ },
    },
  },
};

const data = {
  tags: ['typescript', 'javascript', 'validation'],
  users: [
    { name: 'John Doe', email: '[email protected]' },
    { name: 'Jane Doe', email: '[email protected]' },
  ],
};

if (isValid(data, schema)) {
  console.log('Validation successful!');
} else {
  console.log('Validation failed!');
}

Enums

You can validate that a string value is one of a predefined set of values using the enum property.

import { isValid, ObjectValidationScheme } from 'flex-validator';

const schema: ObjectValidationScheme = {
  status: {
    type: 'string',
    required: true,
    enum: ['active', 'inactive', 'pending'],
  },
};

const data = {
  status: 'active',
};

if (isValid(data, schema)) {
  console.log('Validation successful!');
} else {
  console.log('Validation failed!');
}