Another Validator

Whether you're building a simple form or a complex application, this validator is a valuable tool for validating user input and data.

Features

• Configurable input requirements, such as minimum length, maximum length, lowercase, uppercase, digits, and special characters, making it easy to customize the validation rules to match your specific needs.
• Extensible capabilities. You can add custom validation functions for specific use cases, allowing you to easily create validation rules that are tailored to your application's unique requirements.
• Flexible configuration options, allowing you to specify which validation rules are required and which are optional.
• Customizable error messages.

Usage

Functions

If you only need to validate a simple condition, for example if the string is a mail or an url you can use a simple function. This package provides a set of functions that you can use to validate input. Go to the functions documentation for more information (is below the validators methods).

Validators

This package provides a set of validators that you can use to validate user input.

• Validator - Validates a single input, such as a password or a username.
• NumberValidator - Validates a number.
• CardValidator - Validates a credit card number (Uses Luhn's Algorithm). It can validate a number of different card types, including Visa, MasterCard, American Express, Discover, etc.
• SchemaValidator - Validates an object. It can validate multiple inputs at once. You can nest SchemaValidator for complex objects and arrays.
• ArrayValidator - Validates that each element in an array meets the specified requirements.

Add validations

When you create a new validator, you can specify the validation rules that you want to use. You can also specify the error messages that you want to use for each rule.

If you have specific requirements for your application, you can add custom validation rule. In order to do that you have to create your own validation function. The validation function should return a boolean value. If the function returns true, the input is considered valid. If the function returns false, the input is considered invalid.

Example:

// If no error messages are provided, the default error messages are used
const passwordValidator = new Validator()
  .minLength(5)
  .maxLength(10)
  .requireLowercase("this input requires a lowercase letter")
  .requireUppercase()
  .requireNumber()
  .requireSpecialCharacter()
  .addRule((input) => {
    return !input.includes("example");
  });

const ageValidator = new NumberValidator()
  .min(18)
  .max(65)
  .notNull("this input cannot be null");

const cardValidator = new CardValidator();

const productValidator = new SchemaValidator({
  name: new Validator().notEmpty(),
  price: new NumberValidator().min(0),
  sku: new Validator().fixedLength(10).onlyNumbers(),
});

const productsValidator = new ArrayValidator(productValidator)
  .notEmpty()
  .noDuplicates()
  .comparator((a, b) => a.sku === b.sku);

const schemaValidator = new SchemaValidator({
  username: new Validator().notEmpty(),
  password: passwordValidator, 
  age: ageValidator, 
  card: new CardValidator(), 
  products: productsValidator,
});

schemaValidator.validate(someObject);

Sanitizers

This package offers some sanitizers for strings. You can use them to sanitize user input before validating it.

Available methods

Each validator has three common methods:

• isValid(inpput) - Returns true if the input meets the requirements, otherwise returns false.
• validate(input) - Throws an error if the input does not meet the requirements. The error object contains information about all the errors.
• getErrorMessages(input) - Returns an array of error messages. It does not throw an error.

SchemaValidator and ArrayValidator have a getErrors(input) method that returns an object with the error messages.

You should use getErrors if you want to get detailed information about the errors.

Validator

When setting a max or min these values are inclusive.

NumberValidator

When setting a max or min these values are inclusive.

CardValidator

If it is used with SchemaValidator it will only validate the card number.

If you are using TypeScript, you must use the CardProvider enum to specify the card provider

Providers:

• Visa
• MasterCard
• AmericanExpress
• Discover
• JBC
• DinersClub
• Maestro
• UnionPay
• TarjetaNaranja

SchemaValidator

Usage example:

const validator = new SchemaValidator({
    name: new Validator().notBlank().minLength(3),
    payment: new SchemaValidator({
        sku: new Validator().fixedLength(4).onlyNumbers(),
        price: new NumberValidator().min(0, "cannot be 0 or less"),
        cardNumber: new CardValidator(),
    }),
});

const input = {
    name: ' ',
    payment: {
        cardNumber: '1234',
        sku: '123',
        price: -1,
    },
}

const errors = validator.getErrors(input);

console.log(errors);
/* If no error messages are provided, the default error messages are used:
{
  name: [
    'the value cannot be empty',
    'the value does not meet the minimum length'
  ],
  payment: {
    sku: [ 'the value does not meet the fixed length' ],
    price: [ 'cannot be 0 or less' ],
    cardNumber: [ 'Invalid card number' ]
  }
}
*/

ArrayValidator

If you use noDuplicates without setting a custom comparator function, the validator will use the === operator to check for duplicates. When setting a max or min these values are inclusive.

Usage example:

import { ArrayValidator, CardValidator, NumberValidator, SchemaValidator, Validator } from "another-validator";

const nameValidator = new Validator().minLength(2).maxLength(20).notEmpty();

const validator = new ArrayValidator(nameValidator)
    .minLength(2)
    .maxLength(5)
    .notEmpty()
    .noDuplicates();


const input = ["John", "Doe", "John", ""];

const errors = validator.getErrorMessages(input);

console.log(errors);
/* If no error messages are provided, the default error messages are used:
[
  'the array must not contain any duplicates',
  'the value does not meet the minimum length',
  'the value cannot be empty'
]
*/

Functions

String validations

Credit Card validations

Providers:

• Visa
• MasterCard
• AmericanExpress
• Discover
• JBC
• DinersClub
• Maestro
• UnionPay
• TarjetaNaranja

Example:

isCreditCardValid({
  cardNumber: "4111111111111111", 
  provider: CardProvider.Visa, 
  expirationDate: "12/03"
}); 

Date validations

Sanitizers

TypeScript Support

This library is written in TypeScript and includes type definitions.

Contributing

Contributions are welcome! Please feel free to submit a pull request, report an issue, or suggest new features.

License

This project is licensed under the MIT License.