Diff/Challenges ActiveRecord Playground

experiment.rb

# idea to tinker around with active records with an in memory db from here:
# https://makandracards.com/makandra/32401-activerecord-how-to-use-activerecord-standalone-within-a-ruby-script

# Run this script with `$ ruby my_script.rb`
require 'sqlite3'
require 'active_record'
require 'paper_trail'

# Use `binding.pry` anywhere in this script for easy debugging
require 'pry'

# Connect to an in-memory sqlite3 database
ActiveRecord::Base.establish_connection(
  adapter: 'sqlite3',
  database: ':memory:'
)

# Define a minimal database schema
ActiveRecord::Schema.define do
  create_table :diffs do |t|
    t.string :title
    t.text :source
  end

  create_table :challenges do |t|
    t.string :title
  end

  create_table :reviews do |t|
    t.references :challenge
    t.references :diff
    t.bigint :diff_version_id
  end

  create_table :versions do |t|
    t.string :item_type, null: false
    t.bigint :item_id, null: false
    t.string :event, null: false
    t.string :whodunnit
    t.json :object
    t.json :object_changes
    t.datetime :created_at
  end
end

# Define the models
class Diff < ActiveRecord::Base
  has_paper_trail only: [:source]
  # include ActiveSnapshot

  has_many :reviews

  after_save :create_snapshot_if_reviewed

  private

  def create_snapshot_if_reviewed
    return unless reviews.any?

    reviews.find_each do |review|
      review.update!(diff_version_id: versions.last.id)
    end
  end
end

class Challenge < ActiveRecord::Base
  has_many :reviews
  has_many :diffs, through: :reviews
end

class Review < ActiveRecord::Base
  validates_uniqueness_of :diff_id, scope: :challenge_id

  belongs_to :challenge
  belongs_to :diff

  def source
    original_source || diff.source
  end

  def original_diff
    self.diff.versions.find_by(id: diff_version_id)&.reify
  end

  def outdated?
    original_diff.present?
  end

  def original_source
    original_diff&.source
  end
end

def print_stats(review)
  review.reload
  print <<~HEREDOC
    \nStats:
     review.outdated?: #{review.outdated?}
     review.source: #{review.source}
     actual source: #{review.diff.source}

  HEREDOC
end

diff = Diff.create!(title: 'Big Bang Theory', source: 'original source')
challenge = Challenge.create!(title: 'My Challenge')

review = Review.create!(challenge: challenge, diff: diff)

p "-- diff title updated"
diff.update_attribute(:title, "new title")

print_stats(review)

p "-- diff source updated"
diff.update_attribute(:source, "new source")
print_stats(review)

# outputs:
#
# Stats:
#   review.outdated?: false
# review.source: original source
# actual source: original source
#
# "-- diff source updated"
#
# Stats:
#   review.outdated?: true
# review.source: original source
# actual source: new source