Integrate the jQuery Validation plugin into the Rails asset pipeline

Regressor generates regression specs based on ActiveRecord models. Currently relations, validations, attributes, and database indexes are supported.

Includes a couple of core functions such as callbacks, timestamping, typecasting and lots of generic validation routines.

Phone number validation

Validatable is a library for adding validations.

Rumale::ModelSelection provides model validation techniques, such as k-fold cross-validation, time series cross-validation, and grid search, with Rumale interface.

Validatable is a library for adding validations. Now compatible with Ruby 1.9.2+

AutoStripAttributes helps to remove unnecessary whitespaces from ActiveRecord or ActiveModel attributes. It's good for removing accidental spaces from user inputs. It works by adding a before_validation hook to the record. It has option to set empty strings to nil or to remove extra spaces inside...

Machinery is a systems management toolkit for Linux. It supports configuration discovery, system validation, and service migration. It's based on the idea of a universal system description.

Rack middleware for Weixin apps: message validation/parser/generator

TLSPretense provides a set of tools to test SSL/TLS certificate validation. It includes a library for generating certificates and a test framework for running tests against a client by intercepting client network traffic."

A Ruby wrapper for the World Wide Web Consortium’s online validation services.

Cloudformation tasks for apply(create/update), delete, recreate on stack along with validations on templates

ActiveRecord extension. Allows to save record without calling callbacks and validations.

This plugin gives you the option to not have your custom validation error message prefixed with the attribute name

Introspects your database string field maximum lengths and automatically defines length validations.

Formtastic Plugin for ClientSideValidaitons

SmartProperties are a more flexible and feature-rich alternative to traditional Ruby accessors. They provide support for input conversion, input validation, specifying default values and presence checking.

Add a validation filter to your controller.

Writing specs for complex validations is annoying. AcceptValuesFor makes iteasy to test your validations with real world values, asserting which valuesshould be accepted by your model and which should not.