Я сам нашел выход после нескольких попыток:
it "the queue should be divided into two streams", focus: true do
ap expected = [queue_prop_3_30.id, queue_prop_31_45.id]
common_queue = CommonQueue.all
queue_numbers = common_queue.map { |queue_number| queue_number.queue_id }
ap actual = queue_numbers.uniq
ap expect(expected).to eq(actual)
end