This library helps validate attributes to specific types in the same way that ActiveModel valiations work. Able to chain additional modifiers to each validation.

Keep your code DRY by inferring column validations from table properties! Automagically validate presence, length, numericality, inclusion and uniqueness of ActiveRecord backed columns.

Easily add Judge client side validation to your SimpleForm forms.

Provide validation/generation for UPC/EAN/GTIN numbers

Headhunter is an HTML and CSS validation tool that injects itself into your Rails feature tests and automagically checks all your generated HTML and CSS for validity. In addition, it also looks out for unused (and therefore superfluous) CSS selectors.

A small wrapper around ActiveModel Validations.

A development toolkit for Ruby with several small/cohesive abstractions (monads, enums, business logic, data validation...) to empower your development workflow - It's totally free of dependencies.

DataValidator has almost active_recorde validation methods.

This gem can parse values, validations, documentation, types, groups and conditions of parameters from your puppet modules

This gem helps to create wizard like interfaces in terminal applications, has support for nesting and value validation

AddressValidate is a ruby wrapper for integrating with the USPS address validation api.

Full-featured type system for any ruby project. Supports custom type definition, type validation, type casting and type categorizing. Provides a set of commonly used type categories and general purpose types. Has a flexible and simplest type definition toolchain.

Combine email validation and transformations to produce canonical email addresses.

It validates request params outside your controller logic in order to get a clean and nice code, and also helping with the documentation of the operations.

A managing interface layer for handling the creation and validation of JWTs

Standalone PORO assertions and validations

A wrapper for backbone.validation in the Rails asset pipeline

Interpol is a toolkit for working with API endpoint definition files, giving you a stub app, a schema validation middleware, and browsable documentation.

Validation for Dutch bank account numbers, Citizen Service Numbers (BSN) and Payment reference

Easy client side validation for your ActiveRecord models