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

Method	Description	Parameters
notEmpty	Validates that the input is not empty.	message?: string (optional)
notBlank	Validates that the input is not blank (contains non-whitespace characters).	message?: string (optional)
fixedLength	Validates that the input has a fixed length.	length: number, message?: string (optional)
isEmail	Validates that the input is a valid email.	message?: string (optional)
isUrl	Validates that the input is a valid URL.	message?: string (optional)
minLength	Validates that the input has a minimum length.	length: number, message?: string (optional)
maxLength	Validates that the input has a maximum length.	length: number, message?: string (optional)
requireUppercase	Validates that the input contains at least one uppercase character.	message?: string (optional)
requireLowercase	Validates that the input contains at least one lowercase character.	message?: string (optional)
requireNumber	Validates that the input contains at least one number.	message?: string (optional)
requireSpecialCharacter	Validates that the input contains at least one special character.	message?: string (optional)
noWhitespaces	Validates that the input contains no whitespace characters.	message?: string (optional)
noNumbers	Validates that the input contains no numbers.	message?: string (optional)
noSpecialCharacters	Validates that the input contains no special characters.	message?: string (optional)
onlyNumbers	Validates that the input contains only numbers.	message?: string (optional)
noRepeatedCharacters	Validates that the input contains no repeated characters.	message?: string (optional)
onlyCharacters	Validates that the input contains only alphabetical characters.	message?: string (optional)
addRule	Adds a custom validation rule. 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.	(input?) => boolean, message?: string (optional)

When setting a max or min these values are inclusive.

NumberValidator

Method	Description	Parameters
min	Sets the minimum allowed value for the input.	value: number, message?: string (optional)
max	Sets the maximum allowed value for the input.	value: number, message?: string (optional)
isNegative	Checks if the input is negative	message?: string
isPositive	Checks if the input is positive (bigger than 0)	message?: string
isNonNegative	Checks if the input is non-negative (i.e., zero or positive)	message?: string
addRule	Adds a custom validation rule. 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.	(input?) => boolean, message?: string (optional)

When setting a max or min these values are inclusive.

CardValidator

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

Method	Description	Parameters
isCardProviderValid	Checks if the card number is valid for the given card provider	cardNumber: string, provider: CardProvider
validateExpiration	Validates the expiration date of a credit card	expiration: string
validate	Validates the credit card input based on the card number, provider, and expiration date. The date must have the format (MM/YY)	input: {cardNumber: string, provider?: CardProvider, expirationDate?: string} | string
getErrorMessages	Returns an array of error messages based on the card number, provider, and expiration date	input: {cardNumber: string, provider?: CardProvider, expirationDate?: string} | string
addRule	Adds a custom validation rule. 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.	(input?) => boolean, message?: string (optional)

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

Method	Description	Parameters
getErrors	Returns an object containing error messages for the input object, with keys corresponding to the fields in the schema.	input: any

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

Method	Description	Parameters
minLength	Sets the minimum allowed length for the input array.	value: number, message?: string (optional)
maxLength	Sets the maximum allowed length for the input array.	value: number, message?: string (optional)
notEmpty	Requires the input array to be non-empty.	message?: string (optional)
noDuplicates	Requires the input array to have no duplicate elements.	message?: string (optional)
comparator	Sets the custom comparator function to be used for checking duplicates.	func: (a: any, b: any) => boolean
addRule	Adds a custom validation rule. 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.	(input?) => boolean, message?: string (optional)

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

Method	Description	Parameters
isEmail	Checks if is a valid email address	email: string
isUrl	Checks if is a valid URL. If strict = true, the url must have a valid protocol (https, http), by default this value is false	url: string, strict?: boolean
containsOnlyNumbers	Checks if contains only numbers	input: string
containsOnlyLetters	Checks if contains only letters	input: string
containsUppercase	Checks if contains at least one uppercase letter	input: string
containsLowercase	Checks if contains at least one lowercase letter	input: string
containsSpecialCharacter	Checks if contains at least one special character	input: string
containsNumbers	Checks if contains at least one number	input: string
notContainsNumbers	Checks if does not contain any numbers	input: string
notContainsSpecialCharacter	Checks if does not contain any special characters	input: string
notContainsWhitespace	Checks if does not contain any whitespace	input: string
isIP	Checks if is a valid IP address	input: string
isISO8601	Checks if is a valid ISO 8601 date or datetime string	dateString: string
isBTCAddress	Checks if is a valid Bitcoin address	address: string
isETHAddress	Checks if is a valid Ethereum address	address: string
isJWT	Checks if is a valid JSON Web Token (JWT)	token: string
isNotBlank	Checks if is not blank (contains non-whitespace chars)	input: string
hasLength	Checks if has a specific length	input: string, length: number
isNotEmpty	Checks if is not empty	input: string
containsRepeatedChars	Checks if contains any repeated characters	str: string

Credit Card validations

Method	Description	Parameters
isAValidCreditCardNumber	Checks if a string is a valid credit card number using Luhn algorithm	cardNumber: string
isExpirationDateValid	Checks if a credit card expiration date is valid. The format must be (MM/YY)	expirationDate: string
isCreditCardNumberAndProviderValid	Checks if a credit card number is valid for a given card provider	cardNumber: string, provider: CardProvider
isCreditCardValid	Checks if a credit card has a valid number, provider, and expiration date	{cardNumber: string, provider: CardProvider, expirationDate: string}

Providers:

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

Example:

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

Date validations

Method	Description	Params
isPastDate	Check if a date is in the past	date: Date
isFutureDate	Check if a date is in the future	date: Date
isSameDay	Check if two dates are on the same day	date1: Date, date2: Date
isSameMonth	Check if two dates are in the same month	date1: Date, date2: Date
isSameYear	Check if two dates are in the same year	date1: Date, date2: Date
isLeapYear	Determine if a year is a leap year	year: number
isValidDate	Validate a date object	date: Date
isDateInRange	Check if a date is within a specified range	date: Date, startDate: Date, endDate: Date

Sanitizers

Method	Description	Parameters
keepAlphanumeric	Removes all non-alphanumeric characters from the input string	input: string
keepOnlyNumbers	Keeps only numeric characters in the input string	input: string
keepOnlyCharacters	Keeps only alphabetic characters in the input string	input: string
camelCaseToSnakeCase	Converts a camelCase string to a snake_case string	input: string
snakeCaseToCamelCase	Converts a snake_case string to a camelCase string	input: string
normalizeSpanishInput	Removes tildes from Spanish vowels and replaces ñ with n in the input string	input: string

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.