Unique job showing weird behavior

[kapso]

Given the following worker:

class ReminderWorker < BaseWorker
  sidekiq_options queue: :reminder,
                  unique: true,
                  unique_unlock_order: :never,
                  unique_job_expiration: 7.days.to_i

  def perform(user_id)
    wrap_perform do
      Reminder.call(user_id: user_id)
    end
  end
end

I enqueue the following job:

irb(main)> ReminderWorker.perform_in(7.days, 45)
=> "eb0890b735275ada958c75cd"

I would expect the job to be de-duped, however when I run the following a day later, enqueuing is a success, why? _Is this expected or a bug?_

# A day after enqueuing the above job, enqueuing this job is a success? Why?
irb(main)> ReminderWorker.perform_in(5.seconds, 45)
=> "a8ae57d4ccbfd1922874ad62"

# A minute later, enqueuing job is rejected as expected
irb(main)> ReminderWorker.perform_async(45)
=> nil

Using the following gems:

gem 'sidekiq-unique-jobs', '3.0.15'
gem 'sidekiq', '4.0.1'

[mhenrixon]

Upgrade to 4.0.12