Playing around with one central location to define Feature flags using `Current` as the backing.

feature.rb

# app/models/feature.rb
module Feature
  include Flipper::Context

  flag :like # Assumed to be via: :user
  flag :soon_to_ship_cool_feature, via: :account
end

module Flipper::Context
  def self.included(klass) = klass.extend(ClassMethods, self)

  module ClassMethods
    # Feature.like.enabled? # or Feature.like?
    def flag(*keys, via: :user)
      keys.each do |key|
        define_method(key) { Flag.new(key, via) }
        define_method("#{key}?") { enabled?(key) }
      end
    end
  end

  class Flag < Data.define(:key, :via)
    # Relies on Current.user or Current.account and then the context being read as late as possible
    def enabled?  = Flipper.enabled?(key, Current.public_send(via))
    def disabled? = !enabled?
  
    # Allow Flags to be used as routing constraints, e.g.:
    #   resources :likes, only: %i[create destroy], constraints: Feature.like
    # (haven't tested this yet)
    def matches?(request) = enabled?
  end

  # For dynamic keys, like in requires_feature
  def enabled?(key)  = public_send(key).enabled?
  def disabled?(key) = public_send(key).disabled?
end

def self.requires_feature(key, **)
  before_action(**) { head :bad_request unless Feature.enabled?(key) }
end

class LikesController < ApplicationController
  requires_feature :like
  # requires_feature :like, except: :destroy

  def create
    @like = Like.create(like_params)
    redirect_to @like.article
  end

  def destroy
    @like = Like.find(params[:id]).tap(&:destroy)
    redirect_to @like.article
  end
end