ruby

class AddLockVersionToPosts < ActiveRecord::Migration[6.1]
  def change
    add_column :posts, :lock_version, :integer, default: 0, null: false
  end
end

<%# locals: item %>
<button
  type="button"
  class="toggle-btn"
  data-controller="toggle"
  data-action="click->toggle#toggle"

class PaymentService
  def initialize
    Stripe.api_key = Rails.application.credentials.stripe[:secret_key]
  end

  def create_payment_intent(amount:, currency: 'usd')

class AttachmentContentTypeValidator < ActiveModel::EachValidator
  SIGNATURES = {
    "image/png"       => ["\x89PNG\r\n\x1a\n".b],
    "image/jpeg"      => ["\xFF\xD8\xFF".b],
    "image/gif"       => ["GIF87a".b, "GIF89a".b],
    "application/pdf" => ["%PDF-".b]

class Task < ApplicationRecord
  POSITION_GAP = 1024

  belongs_to :board

  scope :ordered, -> { order(:position) }

class SlidingWindowLimiter
  Result = Struct.new(:allowed, :count, :limit, :window_ms, keyword_init: true)

  SCRIPT = <<~LUA.freeze
    local key = KEYS[1]
    local now = tonumber(ARGV[1])

class Reminder < ApplicationRecord
  belongs_to :user

  validates :time_zone, inclusion: { in: ActiveSupport::TimeZone::MAPPING.values }
  validates :local_time, presence: true

class DebouncedReindexJob
  include Sidekiq::Job

  sidekiq_options queue: :indexing, retry: 5

  DEBOUNCE_DELAY = 5 # seconds

require 'sinatra/base'
require_relative 'cart'
require_relative 'cart_helpers'

class StoreApp < Sinatra::Base
  enable :sessions

module FlashHelper
  FLASH_CLASSES = {
    "notice" => "flash--success",
    "alert"  => "flash--error",
    "error"  => "flash--error"
  }.freeze

module Api
  module V1
    class PostsController < BaseController
      before_action :authenticate_user!

      def create

class ApplicationError < StandardError
  attr_reader :context

  class << self
    def context_keys(*keys)
      @context_keys = keys unless keys.empty?