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Form Validator

Form Validator is a lightweight npm package that provides a set of validation rules to validate form fields. It can be used in any JavaScript or TypeScript project to handle form input validation and ensure data integrity.

Features

• Provides common form validation rules (e.g., required fields, email validation, min/max length, etc.).
• Supports both JavaScript and TypeScript projects.
• Lightweight and easy to use.

Installation

To install the Form Validator package, use npm or yarn:

npm install form-validator

or

yarn add form-validator

Usage

import { validateField } from 'form-validator';

// Example usage const value = '[e-mail]'; const rules = ['required', 'email'];

const result = validateField(value, rules);

console.log(result.isValid); // true if validation passes, false otherwise console.log(result.errorMessage); // error message if validation fails, empty string if validation passes

Validation Rules

The validateField function accepts an input value and an array of validation rules. The supported validation rules are as follows:

required: Checks if the field is not empty. minLength: Validates the minimum length of the field (default: 5 characters). maxLength: Validates the maximum length of the field (default: 20 characters). email: Validates if the input is a valid email address. numeric: Validates if the input is a valid number. url: Validates if the input is a valid URL. password: Validates if the input meets the criteria for a strong password. minValue: Validates the minimum numeric value (default: 10). maxValue: Validates the maximum numeric value (default: 100). startsWith: Validates if the input starts with a specific value (default: empty string). endsWith: Validates if the input ends with a specific value (default: empty string).

Example

import { validateField } from 'form-validator';

const value = 'abc'; const email = '[e-mail]'; const age = '25'; const website = 'https://www.example.com'; const password = 'Abc123';

const result1 = validateField(value, ['required', 'minLength']); console.log(result1.isValid); // false, as value is less than 5 characters

const result2 = validateField(email, ['required', 'email']); console.log(result2.isValid); // true, as email is valid

const result3 = validateField(age, ['numeric', 'minValue:18']); console.log(result3.isValid); // true, as age is numeric and greater than or equal to 18

const result4 = validateField(website, ['url']); console.log(result4.isValid); // true, as website is a valid URL

const result5 = validateField(password, ['password']); console.log(result5.isValid); // true, as password meets the criteria for a strong password