Example for Rails 4 Timestamp/Callback order regression.

record_timestamps_and_callbacks_regression_example.rb

class Thing < ActiveRecord::Base
  before_update :skip_record_timestamps
  def skip_record_timestamps
    self.record_timestamps = false
    return true
  end

  after_update :reset_record_timestamps
  def reset_record_timestamps
    self.record_timestamps = true
  end
end

# This passed in Rails 3, but not Rails 4.
t = Thing.find(1)
expected = t.updated_at
t.update_attributes(name: 'new name')
assert_equal expected, t.updated_at