TypedAttrs integrates Sorbet's T::Struct with ActiveRecord's JSON/JSONB columns, providing type-safe structured data storage with runtime and static type checking. Supports nested structs, arrays, hashes, union types, and automatic validation.

A new check for puppet-lint that validates that all parameters are typed.

A puppet-lint plugin to check that Optional class/defined type parameters don't default to anything other than `undef`.

Type checking tasks for Bake.

Check yardoc format like tag type.

strong_csv is a type checker for a CSV file. It lets developers declare types for each column to ensure all cells are satisfied with desired types.

LCN (Location Condition Notation) provides a rule-agnostic format for describing location conditions in abstract strategy board games. This gem implements the LCN Specification v1.0.0 with a modern Ruby interface featuring immutable condition objects and functional programming principles. LCN enables standardized representation of environmental constraints on board locations using reserved keywords ("empty", "enemy") and QPI piece identifiers with CELL coordinate system integration. Perfect for movement validation, pre-condition checking, constraint evaluation, and rule-agnostic game logic requiring precise location state requirements across multiple game types and traditions.

A tiny pre-processor for ruby that adds runtime type checking to methods.

A puppet-lint plugin to check for class parameters with undef as value but not Optional type

Kumi is a declarative rules-and-calculation DSL for Ruby that compiles your business logic into a typed, analyzable dependency graph with vector semantics over ragged data. It does static checks at definition time, lowers to a small IR, and compiles to zero-runtime modules

Enums, properties, generics, structured objects and runtime type checking.

A lightweight gem that validates required environment variables at application boot time, providing type checking, format validation, and helpful error messages to prevent production disasters caused by missing or invalid configuration.

EnvCheck is a lightweight Ruby gem that ensures your required and optional environment variables are present and valid before your app boots. Features smart config discovery (.env_check.yml or config/env_check.yml), comprehensive type validation with 9 built-in validators, .env loading with dotenv, and professional CLI tools. Framework-agnostic design works with Rails 7.1+ through Rails 8.0+, Ruby 3.0+.

ruby-contract provides support for describing and using types via unit-tests. It offers support for specifying contracts (Contract), method signature checks (Module#signature), automatic adaption between types (Kernel#adaption) and integration with the classic message- and class-based typing.

Methods for defining type-checked arrays and attributes

The strongtyping gem is a Ruby library that provides type checking and method overloading.

The code to check for the iPhone user agent is from http://developer.apple.com. This doesn't have any dependencies. - in app/controllers/application.rb require 'is_it_iphone' class ApplicationController < ActionController::Base include IsItIPhone before_filter :adjust_format_for_iphone # Always show iPhone views end You will have these functions: iphone_user_agent? Returns true if the user agent is an iPhone. (as spec'ed on http://developer.apple.com) iphone_request? Returns true if the request came from an iPhone. Override being an iPhone with ?format=xxxx in the URL. adjust_format_for_iphone Call when you want to show iPhone views to iPhone users. Note: It is recommended by Apple that you default to showing your "normal" html page to iPhone users and allow them to choose if they want an iPhone version. With Rails 2.0, you can use its multiview capabilities by simply adding this to your app: - in config/initializers/mime_types.rb Mime::Type.register_alias "text/html", :iphone Then, just create your views using suffices of iphone.erb instead of html.erb: index.iphone.erb show.iphone.erb etc. Note: you will probably want to use a Web library specific for iPhone applications. FWIW, I use Da shcode (in the iPhone SDK) to write and debug the iPhone application and then integrate it with my Rails project.

QuacksLike is a module for RSpec to add matchers that test if an object is fully duck-typed to pretend to be another class. This kind of thing is really only necessary when passing such an object as the return value in an API where you don't know exactly how it will be consumed, but it needs to "quack like an Array" or something. It does its job by checking every instance method in the class that the target object needs to "quack like" and makes sure the target both responds to that method name and that the arity of the method is appropriate.

RubyLess is an interpreter for "safe ruby". The idea is to transform some "unsafe" ruby code into safe, type checked ruby, eventually rewriting some variables or methods.

Allows checking of reply content type with request accept types. Also allows contracting of downstream apps to supplying a single type.