vanilla-rails-models

name	vanilla-rails-models
description	Use when writing Rails models - enforces state-as-records not booleans, concerns as adjectives namespaced under model, and concern extraction triggers

Vanilla Rails Models

Rich domain models with concerns. Decompose with concerns, not services.

For method ordering and private indentation rules, see vanilla-rails-style.

State as Separate Records (NOT Booleans)

Don't use boolean columns for state. Create state records that capture who/when.

# Bad - boolean
add_column :cards, :starred, :boolean, default: false

# Good - state record
create_table :stars, id: :uuid do |t|
  t.uuid :card_id, null: false
  t.uuid :user_id, null: false
  t.timestamps
end

class Card < ApplicationRecord
  has_one :star, dependent: :destroy

  def star(user: Current.user)
    create_star!(user: user) unless starred?
  end

  def starred?
    star.present?
  end
end

Binary state (one per item): has_one — closure, triage, goldness

Multi-user state: has_many — pins, watches, assignments

Concerns as Adjectives, Namespaced Under Model

Name as adjectives (-able/-ible ONLY). Namespace under the model. File at app/models/card/closeable.rb.

Wrong	Right	Why
Card::Closing	Card::Closeable	Verb → adjective
Card::Stars	Card::Starrable	Noun → adjective
Card::Closed	Card::Closeable	Past participle → capability
Starrable	Card::Starrable	Must namespace under model
concerns/starrable.rb	card/starrable.rb	File under model directory

Full pattern:

# app/models/card/closeable.rb
module Card::Closeable
  extend ActiveSupport::Concern

  included do
    has_one :closure, dependent: :destroy
    scope :closed, -> { joins(:closure) }
    scope :open, -> { where.missing(:closure) }
  end

  def close(user: Current.user)
    unless closed?
      transaction do
        create_closure!(user: user)
        track_event :closed, creator: user
      end
    end
  end

  def reopen(user: Current.user)
    if closed?
      transaction do
        closure&.destroy
        track_event :reopened, creator: user
      end
    end
  end

  def closed?
    closure.present?
  end
end

Multi-user pattern:

module Card::Pinnable
  extend ActiveSupport::Concern

  included do
    has_many :pins, dependent: :destroy
  end

  def pinned_by?(user)
    pins.exists?(user: user)
  end

  def pin_by(user)
    pins.find_or_create_by!(user: user)
  end

  def unpin_by(user)
    pins.find_by(user: user)&.destroy
  end
end

When to Extract

• Feature adds 3+ methods to model
• Clear adjective name exists (-able/-ible)
• Even if only one model uses it (decomposition, not just reuse)
• Model exceeds ~100 lines

Red Flags

Red flag	Fix
Boolean column for state	State record table (see data-modeling)
Concern not ending in -able/-ible	Rename immediately
Concern not namespaced under model	Move to Card::Closeable
Concern in app/models/concerns/ for single model	Move to app/models/card/
Service object for domain logic	Rich model method instead
"Only extract if reused"	Extract for decomposition at 3+ methods