Testing sidekiq worker using rspec-sidekiq not working

Question

This is my test code:

require 'rails_helper'

describe CookCookieWorker do
  let(:user) { FactoryGirl.create(:user) }
  let(:oven) { user.ovens.first }

  it { is_expected.to be_processed_in :cookies }

  it 'enqueues the cook cookies worker to be processed in 5 seconds' do
    oven.cookies.create!({ fillings: 'Vanilla' })
    cookie = oven.cookies.last

    expect(CookCookieWorker).to have_enqueued_sidekiq_job(cookie.id).in(5.seconds)
  end
end

And this is the result I get

expected to have an enqueued CookCookieWorker job
         arguments: [1]
         options: {"in"=>5 seconds}
       found
         arguments: []
         options: []

Just to clarify, I have an after_save callback in the Cookie model that calls the worker this way:

CookCookieWorker.perform_in(5.seconds, id)

at the beginning I thought that probably I could not test the worker this way, probably the model callbacks doesn't have effect? However I tried to manually call the worker in the test:

require 'rails_helper'

describe CookCookieWorker do
  let(:user) { FactoryGirl.create(:user) }
  let(:oven) { user.ovens.first }

  it { is_expected.to be_processed_in :cookies }

  it 'enqueues the cook cookies worker to be processed in 5 seconds' do
    oven.cookies.create!({ fillings: 'Vanilla' })
    cookie = oven.cookies.last

    CookCookieWorker.perform_in(5.seconds, cookie.id) # Calling it manually
    expect(CookCookieWorker).to have_enqueued_sidekiq_job(cookie.id).in(5.seconds)
  end
end

But I get the same result, the test fails. Any idea?