Checkmate

checkmate-ts is a library for validating objects in TypeScript applications. It supports validating various data types, nested objects, arrays, and custom rules, ensuring type safety and reliability in data validation scenarios.

Usage

import {Validator} from 'checkmate-ts'

const {user, title, topics} = Validator.create({
  'title': ['string', 'required', 'min:8'],
  'topics': ['array', 'min:1'],
  'topics.*': ['string', 'required'],
  'user': ['required'],
  'user.id': ['required', 'number'],
  'user.name': ['required', 'string'],
  'user.role': ['required', 'in:admin,moderator']
}).validateObject<{
  title: string,
  topics: string[],
  user: {
    id: number,
    name: string,
    role: 'admin' | 'moderator'
  }
}>(res)

Important information

Nested arrays currently only work with one level.

Installation

You can install the package via npm:

npm install checkmate-ts

Or via yarn:

yarn add checkmate-ts

Rules

The validator supports the following rules:

required: The field must be present.

string: The field must be a string.

number: The field must be a number.

array: The field must be an array.

min<number>: The field must be a string with a minimum length of .

max:<number>: The field must be a string with a maximum length of .

email: The field must be a valid email address.

in:<values>: The field value must be one of the specified .

Methods

Create

create<R extends Rules>(rules: R): Validator<R>

Creates a new instance of the Validator class with specified validation rules.

parameters: rules - The rules to match against returns: validator - An instance of the validator

validateObject

validateObject<T>(data: T): T Validates the provided data object against the rules defined in the validator instance.

parameters: data - The object to be validated returns: data - The data object, it doesn't mutate this object in any way.

Example

import {ValidationError, Validator} from 'checkmate-ts'

// Define validator with rules
const validator = Validator.create({
  // Simple fields
  'name': ['required', 'string', 'min:3', 'max:50'],
  'age': ['required', 'number'],

  // Nested object
  'address.street': ['string'],
  'address.city': ['required', 'string'],

  // Array of strings
  'skills': ['array'],
  'skills.*': ['string'],

  'email': ['required', 'email'],

  // Must be either "active" or "inactive"
  'status': ['in:active,inactive'],
})

const data = {
  name: 'John Doe',
  age: 30,
  address: {
    street: '123 Main St',
    city: 'Anytown'
  },
  skills: ['JavaScript', 'TypeScript'],
  email: '[email protected]',
  status: 'active'
}

try {
  // Validate the data object
  const validatedData = validator.validateObject<{
    name: string,
    age: number,
    address: {
      street?: string,
      city: string
    },
    skills: string[],
    email: string,
    status: 'active' | 'inactive'
  }>(data)

} catch (error) {
  if (error instanceof ValidationError) {
    console.log(error.errors)
  }
}