Fortress Validator

A powerful and flexible form validation library, built to validate inputs through method chaining, with support for custom plugins.

Getting Started

Using with ES Modules

To get started with ES Modules, simply import the module and use it in your code:

import { FormValidator } from '@fortress-validator/fortress';

const validator = new FormValidator();

Using with UMD Modules

Alternatively, if you're using UMD modules, include the script in your HTML file and use it in your code:

<script src="https://unpkg.com/@fortress-validator/fortress/dist/index.umd.js"></script>
<script>
const validator = new window.Fortress.FormValidator();
</script>

Usage

Basic Validation

The defineField method sets up a field for validation, allowing you to chain validation rules like required and others to validate the input.

document.querySelector('input').addEventListener('input', (e) => {
  const result = validator
    .defineField('Input')
    .required()
    .alphaDash()
    .validate(e.target.value);

  console.log(result);
});

Conditional Validation

The when method allows you to conditionally apply validation rules like required and others based on specific conditions.

const result = validator
  .defineField('Input')
  .when({
    alphaDash: false,
  })
  .required()
  .alphaDash()
  .validate('@');

// Result:
// true

Available Rules

Name	Description
accepted	Passes if the field's value is considered accepted (i.e., "y", "yes", "on", "1", "true").
after	Passes if the field's value is a date that occurs after the specified date.
alpha	Passes if the field's value contains only letters.
alphaDash	Passes if the field's value contains only letters, numbers, dashes and underscores.
alphaDashDot	Passes if the field's value contains only letters, numbers, dashes, underscores and dots.
alphaNum	Passes if the field's value contains only letters and numbers.
array	Passes if the field's value is an array.
arrayLength	Passes if the field's length matches the specified length.
arrayLengthBetween	Passes if the field's length is between the specified minimum and maximum lengths.
arrayLengthGt	Passes if the field's length is greater than the specified length.
arrayLengthGte	Passes if the field's length is greater than or equal to the specified length.
arrayLengthLt	Passes if the field's length is less than the specified length.
arrayLengthLte	Passes if the field's length is less than or equal to the specified length.
ascii	Passes if the field's value contains only ASCII characters and symbols.
before	Passes if the field's value is a date that occurs before the specified date.
between	Passes if the field's value is between the specified minimum and maximum values.
boolean	Passes if the field's value is a boolean.
containsAll	Passes if the field's value contains all of the specified values.
containsAny	Passes if the field's value contains at least one of the specified values.
date	Passes if the field's value matches the specified date format.
declined	Passes if the field's value is considered declined (i.e., "n", "no", "off", "0", "false").
different	Passes if the field's value is different from the specified value in the given field.
distinct	Passes if the field's value contains only unique items.
domain	Passes if the field's value is a valid domain.
email	Passes if the field's value is a valid email address.
endsWith	Passes if the field's value ends with the specified value.
equals	Passes if the field's value is equal to the specified value.
file	Passes if the field's value is a file.
fileSize	Passes if the field's file size matches the specified file size.
fileSizeBetween	Passes if the field's file size is between the specified minimum and maximum file sizes.
fileSizeGt	Passes if the field's file size is greater than the specified file size.
fileSizeGte	Passes if the field's file size is greater than or equal to the specified file size.
fileSizeLt	Passes if the field's file size is less than the specified file size.
fileSizeLte	Passes if the field's file size is less than or equal to the specified file size.
gt	Passes if the field's value is greater than the specified value.
gte	Passes if the field's value is greater than or equal to the specified value.
http	Passes if the field's value starts with the "http://" protocol.
httpOrHttps	Passes if the field's value starts with the "http://" or "https://" protocols.
https	Passes if the field's value starts with the "https://" protocol.
integer	Passes if the field's value is an integer.
ip	Passes if the field's value is a valid IP address.
ipv4	Passes if the field's value is a valid IPv4 address.
ipv6	Passes if the field's value is a valid IPv6 address.
iso8601	Passes if the field's value is a valid ISO 8601 date.
json	Passes if the field's value is a valid JSON string.
jsonSchema	Passes if the field's value matches the specified JSON schema.
lowercase	Passes if the field's value contains only lowercase characters.
lt	Passes if the field's value is less than the specified value.
lte	Passes if the field's value is less than or equal to the specified value.
notContainsAll	Passes if the field's value does not contain all of the specified values together.
notContainsAny	Passes if the field's value does not contain any of the specified values.
notEndsWith	Passes if the field's value does not end with the specified value.
notEquals	Passes if the field's value is not equal to the specified value.
notOneOf	Passes if the field's value is not one of the specified values.
notStartsWith	Passes if the field's value does not start with the specified value.
notStartsWithNumber	Passes if the field's value does not start with a number.
notSubsetOf	Passes if the field's value is not a subset of the specified values.
number	Passes if the field's value is a number.
numeric	Passes if the field's value contains only numeric characters.
object	Passes if the field's value is an object.
oneOf	Passes if the field's value is one of the specified values.
protocol	Passes if the field's value starts with the specified protocol.
regex	Passes if the field's value matches the specified regular expression.
required	Passes if the field's value is not empty.
requiredWhen	Passes if the field's value is not empty when the specified condition is true.
same	Passes if the field's value is the same as the specified value in the given field.
size	Passes if the field's value matches the specified size.
startsWith	Passes if the field's value starts with the specified value.
startsWithNumber	Passes if the field's value starts with a number.
string	Passes if the field's value is a string.
stringContainsAll	Passes if the field's value contains all of the specified text.
stringContainsAny	Passes if the field's value contains at least one of the specified text.
stringLength	Passes if the field's string length matches the specified string length.
stringLengthBetween	Passes if the field's string length is between the specified minimum and maximum string lengths.
stringLengthGt	Passes if the field's string length is greater than the specified string length.
stringLengthGte	Passes if the field's string length is greater than or equal to the specified string length.
stringLengthLt	Passes if the field's string length is less than the specified string length.
stringLengthLte	Passes if the field's string length is less than or equal to the specified string length.
stringNotContainsAll	Passes if the field's value does not contain all of the specified text together.
stringNotContainsAny	Passes if the field's value does not contain any of the specified text.
subsetOf	Passes if the field's value is a subset of the specified values.
unique	Passes if the field's value does not exist in the provided values.
uppercase	Passes if the field's value contains only uppercase characters.
url	Passes if the field's value is a valid URL.

Available Methods

Name	Description
collect	Collects the rule functions.
validate	Validates the field's value.
apply	Applies the specified rule with the given arguments, useful for applying custom rules.
when	Determines whether to apply or skip validation based on the provided conditions.

Available Plugins

• fortress-validator/plugin-date
• fortress-validator/plugin-json-schema

Custom Plugin

A custom plugin is composed of rules and locales, allowing you to define custom validation logic and locale-specific messages.

const validator = new FormValidator({
  plugins: [
    {
      rules: {
        multipleOf: (({ factor }: { factor: number }) => (input: unknown) => Number(input) % factor === 0) as Rule<unknown>,
      },
      locales: {
        en: {
          multipleOf: (field, args) => {
            const { factor } = args as { factor: number };
            return `The ${field} field must be a multiple of ${factor}.`;
          },
        },
      },
    },
  ],
});

const result = validator
  .defineField('Input')
  .apply('multipleOf', { factor: 2 })
  .validate(1);

// Result:
// The input field must be a multiple of 2.

Development

To start a local development server, run:

npm run dev

Testing

To run the tests for this package, run:

npm run test

Contributors