Form Validation Library

Description

form-validation-lib is a simple and customizable JavaScript library designed for handling form validation and error messages in web applications. It provides a set of validation functions to ensure that user inputs meet specific criteria, such as required fields, valid email addresses, password complexity, and more.

Installation

To install the library, use npm:

npm install form-validation-lib

Usage

Importing the Library

First, import the validation functions into your project:

const {
  validateRequired,
  validateEmail,
  validateMinLength,
  validateMaxLength,
  validateAlphanumeric,
  validateSpecialChars,
  validateNumeric,
  validateRange,
  validatePasswordComplexity,
  validateDate,
  validatePhoneNumber,
  validateURL,
  validateMatch
} = require('form-validation-lib');

Available Functions

validateRequired(value, message)

• Description: Validates that the input is not empty.
• Parameters:
  • value (string): The input value to validate.
  • message (string, optional): The error message to return if validation fails. Default is "This field is required".
• Returns: true if valid; otherwise, the error message.

validateEmail(value, message)

• Description: Validates the format of an email address.
• Parameters:
  • value (string): The email address to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Invalid email address".
• Returns: true if valid; otherwise, the error message.

validateMinLength(value, min, message)

• Description: Validates that the input meets the minimum length requirement.
• Parameters:
  • value (string): The input value to validate.
  • min (number): The minimum length requirement.
  • message (string, optional): The error message to return if validation fails. Default is "Minimum length is X", where X is the minimum length.
• Returns: true if valid; otherwise, the error message.

validateMaxLength(value, max, message)

• Description: Validates that the input does not exceed the maximum length.
• Parameters:
  • value (string): The input value to validate.
  • max (number): The maximum length requirement.
  • message (string, optional): The error message to return if validation fails. Default is "Maximum length is X", where X is the maximum length.
• Returns: true if valid; otherwise, the error message.

validateAlphanumeric(value, message)

• Description: Validates that the input contains only letters and numbers.
• Parameters:
  • value (string): The input value to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Only letters and numbers are allowed".
• Returns: true if valid; otherwise, the error message.

validateSpecialChars(value, allowedChars, message)

• Description: Validates that the input contains only allowed special characters.
• Parameters:
  • value (string): The input value to validate.
  • allowedChars (string): A string of allowed special characters.
  • message (string, optional): The error message to return if validation fails. Default is "Allowed characters: X", where X is the allowed characters.
• Returns: true if valid; otherwise, the error message.

validateNumeric(value, message)

• Description: Validates that the input is a number.
• Parameters:
  • value (string | number): The input value to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Must be a number".
• Returns: true if valid; otherwise, the error message.

validateRange(value, min, max, message)

• Description: Validates that the input is within a specified range.
• Parameters:
  • value (number): The input value to validate.
  • min (number): The minimum value.
  • max (number): The maximum value.
  • message (string, optional): The error message to return if validation fails. Default is "Must be between X and Y", where X is the minimum and Y is the maximum.
• Returns: true if valid; otherwise, the error message.

validatePasswordComplexity(value, message)

• Description: Validates the complexity of a password.
• Parameters:
  • value (string): The password to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Password must include uppercase, lowercase, numbers, and special characters".
• Returns: true if valid; otherwise, the error message.

validateDate(value, message)

• Description: Validates the format of a date (YYYY-MM-DD).
• Parameters:
  • value (string): The date to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Invalid date format".
• Returns: true if valid; otherwise, the error message.

validatePhoneNumber(value, message)

• Description: Validates the format of a phone number.
• Parameters:
  • value (string): The phone number to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Invalid phone number".
• Returns: true if valid; otherwise, the error message.

validateURL(value, message)

• Description: Validates the format of a URL.
• Parameters:
  • value (string): The URL to validate.
  • message (string, optional): The error message to return if validation fails. Default is "Invalid URL".
• Returns: true if valid; otherwise, the error message.

validateMatch(value, compareTo, message)

• Description: Validates that the input matches a specified value.
• Parameters:
  • value (string): The input value to validate.
  • compareTo (string): The value to compare against.
  • message (string, optional): The error message to return if validation fails. Default is "Fields do not match".
• Returns: true if valid; otherwise, the error message.

Running Tests

To run tests for the library, use the following command:

npm test

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please open an issue or submit a pull request on the GitHub repository.

Contact

For any questions or feedback, you can reach me at Syed Fardeen Jeelani.