igmarin/rails-agent-skills

Curated library of 41 public AI agent skills for Ruby on Rails development. Organized by category: planning, testing, code-quality, ddd, engines, infrastructure, api, patterns, context, and orchestration. Covers code review, architecture, security, testing (RSpec), engines, service objects, DDD patterns, and TDD automation. Repository workflows remain documented in GitHub but are intentionally excluded from the Tessl tile.

1.77x

Quality

93%

Does it follow best practices?

Impact

96%

1.77x

Average score across 41 eval scenarios

Securityby

Passed

No known issues

DDD Rails Modeling Examples

Name: igmarin/rails-agent-skills
Rating: 95.72 (1 reviews)
Author: igmarin

Value Object — Money

# app/models/money.rb
class Money
  attr_reader :amount_cents, :currency

  def initialize(amount_cents, currency = "USD")
    @amount_cents = Integer(amount_cents)
    @currency = currency.upcase.freeze
    freeze
  end

  def ==(other)
    other.is_a?(Money) && amount_cents == other.amount_cents && currency == other.currency
  end

  alias eql? ==

  def hash
    [amount_cents, currency].hash
  end
end

Modeling choice: Value object — equality by value, immutable, no database identity needed.
Suggested home: app/models/money.rb
Avoid: Adding belongs_to or a database table — this is a calculation value, not an entity.

Application Service — CreateOrder

# app/services/orders/create_order.rb
module Orders
  class CreateOrder
    Result = Struct.new(:success?, :order, :errors, keyword_init: true)

    def self.call(**args) = new(**args).call

    def initialize(user:, product_id:, quantity:)
      @user, @product_id, @quantity = user, product_id, quantity
    end

    def call
      order = @user.orders.build(product: Product.find(@product_id), quantity: @quantity)
      order.save ? Result.new(success?: true, order: order, errors: [])
                 : Result.new(success?: false, order: nil, errors: order.errors.full_messages)
    rescue ActiveRecord::RecordNotFound
      Result.new(success?: false, order: nil, errors: ["Product not found"])
    end
  end
end

Modeling choice: Application service — coordinates persistence and follows up side effects for one use case.
Suggested home: app/services/orders/create_order.rb
Avoid: Fat controller method or a callback chain on Order.

Domain Event — OrderCreated

# app/events/orders/order_created_event.rb
module Orders
  class OrderCreatedEvent
    attr_reader :order_id, :occurred_at

    def initialize(order_id:)
      @order_id = order_id
      @occurred_at = Time.current.freeze
    end
  end
end

Modeling choice: Domain event — record of something that happened in the domain.
Suggested home: app/events/orders/order_created_event.rb

JSON Mapping (Machine Readable)

{
  "aggregates": [
    {
      "name": "Order",
      "model": "Order",
      "repository": "OrderRepository",
      "services": ["OrderCreator", "OrderCanceler"],
      "events": ["order.created", "order.canceled"],
      "owner": "team-orders"
    }
  ],
  "bounded_contexts": [
    {"name": "Orders", "path": "app/models/order*", "owner": "team-orders"},
    {"name": "Billing", "path": "app/services/billing/*", "owner": "team-billing"}
  ]
}