Interactors are a pattern for structuring your business logic into units. They have a flexible context that they pass between them, which makes them easy-to-write, but hard-to-understand after you've written them. Much of this confusion comes from not knowing what the interactor is supposed to ta...

Handles application errors and model validations

Validatable is a library for adding validations.

CPF and CNPJ validations for ActiveModel and Rails

A Rails plugin that adds an ActiveRecord validation helper to do range and start/end date checking in.

Schema-based validation and coercion for Ruby data structures, inspired by Prismatic/schema for Clojure.

Callback Hell analyzes your Rails application models and provides useful insights on callbacks and validations defined

Model.validates { presence_of :name }

A custom validation for your Active Model that check if an array is included in another one

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.

Provides JSON Schema validation for ElasticGraph.

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

Personnummer handles validation of Swedish personal identity numbers.

IBAN + SWIFT/BIC: Information, Validation and Formatting.

Provides a form field validation JavaScript library for your Rails application. Built for use with jQuery and Twitter Bootstrap 3. Source code: https://github.com/nghuuphuoc/bootstrapvalidator

Ruby gem for runtime data validation and monitoring using the contracts approach.

Easily add Judge client side validation to your SimpleForm forms.

LHS ia a Rails-Gem, providing an ActiveRecord like interface to access HTTP-JSON-Services from Rails Applications. Special features provided by this gem are: Multiple endpoint configuration per resource, active-record-like query-chains, scopes, error handling, relations, request cycle cache, batc...