Ignore or Skip attributes dynamically is not working

[pgonzaga]

• This is not a usage question, this is a bug report
• This bug can be reproduced with the script I provide below
• This bug can be reproduced in the latest release of the paper_trail gem

# frozen_string_literal: true

# Use this template to report PaperTrail bugs.
# Please include only the minimum code necessary to reproduce your issue.
require "bundler/inline"

# STEP ONE: What versions are you using?
gem 'paper_trail', '10.3.1'
gem 'rails', '5.2.3'

ActiveRecord::Schema.define do
  # STEP TWO: Define your tables here.
  create_table :users, force: true do |t|
    t.text :first_name, null: false
    t.timestamps null: false
  end

  create_table :versions do |t|
    t.string :item_type, null: false
    t.integer :item_id, null: false
    t.string :event, null: false
    t.string :whodunnit
    t.text :object, limit: 1_073_741_823
    t.text :object_changes, limit: 1_073_741_823
    t.datetime :created_at
  end
  add_index :versions, %i[item_type item_id]
end
ActiveRecord::Base.logger = Logger.new(STDOUT)
require "paper_trail"

# STEP FOUR: Define your AR models here.
class User < ActiveRecord::Base
  has_paper_trail on: %i[update destroy], ignore: { first_name: Proc.new { |obj|  true } }
end

# STEP FIVE: Please write a test that demonstrates your issue.
class BugTest < ActiveSupport::TestCase
  def test_1
    User.create(first_name: "Jane")
    assert_difference(-> { PaperTrail::Version.count },  0) {
      User.update(first_name: "Jane 2")
    }
  end
end

# STEP SIX: Run this script using `ruby my_bug_report.rb`

[tlynam]

Thank you for creating this bug report! I was able to reproduce the issue with your script and investigating.

[tlynam]

Hi @pgonzaga, it looks like a version is being created during an update because updated_at is being recorded as a change. Can you confirm this is the case for you?

user = User.create(first_name: 'jane')
user.update(first_name: 'jane 2')
user.versions.size
=> 1
user.versions.first.changeset
=> {"updated_at"=>[Sun, 26 Apr 2020 19:31:39 UTC +00:00, Sun, 26 Apr 2020 19:31:41 UTC +00:00]}

[tlynam]

Hi @pgonzaga, were you able to see if a version is being created during an update because updated_at is being recorded as a change?

[guigs]

I also encountered this issue. When using ignore: %w[foo] it also ignore changes in updated_at, but when using with a proc like ignore: { foo: Proc.new { |obj| true } } it does not ignore changes in updated_at.

I think this is a surprising behavior, and a bug. I think the cause and possible fix is in the method ignored_attr_has_changed? which doesn't consider ignore attributes with a Proc and it is called by changed_notably? method.

[tlynam]

Thank you @guigs! Now I understand the issue. Thank you also for pointing out where to fix this. I opened #1247 for a fix.