Should reading store accessor for attribute, initialize/mutate nil store attribute?

rubyonrails-core
1

If you are using store_accessor (such as for a JSONB column in postgres) and the attribute is nil, reading from any of your accessors for the attribute initializes the attribute to empty hash. This makes the object dirty which has implications downstream such as if you try to lock the object later on. So my question is, should reading an accessor on the attribute result in the attribute itself being mutated?

Example

# 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", "7.0.3.1"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
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 :posts, force: true do |t|
    t.json :data
  end
end

class Post < ActiveRecord::Base
  store_accessor :data, :title
end

class StoreTest < Minitest::Test
  def test_store
    post = Post.create!

    # data = nil
    refute post.changed?
    assert_nil post.title
    # fails because data = {} from previous accessor call to title
    refute post.changed?
  end
end

If not, fixing this seems fairly straight forward in read here rails/store.rb at a3d15ade680dac2f8a90293b6cf123aa13e8c72c · rails/rails · GitHub