deprecation.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "activerecord", "6.0.3.2"
  gem "sqlite3"
end

require "active_record"
require "logger"

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :authors, force: true do |t|
  end

  create_table :posts, force: true do |t|
    t.references :author
    t.timestamps
  end
end

class Author < ActiveRecord::Base
  has_many :posts
end

class Post < ActiveRecord::Base
  belongs_to :author

  validate :rate_limit

  def rate_limit
    if Post.where(author: author_id).where('created_at > ?', 1.hour.ago).any?
      errors[:base] << 'Rate limit reached'
    end
  end
end

Post.where(author_id: 1).first_or_create