Convert random seed to a small value

We are trying out a modulus function to return investments in random
order https://github.com/consul/consul/pull/2131

However we ran into the gotcha of having a seed value too big for the
modulus function to work as expected

If the seed is bigger than the investment id, the records are returned
ordered by id

By dividing the seed by a big number, this problem seems to get fixed

app/controllers/budgets/investments_controller.rb

@@ -112,7 +112,8 @@ module Budgets
       def set_random_seed
         if params[:order] == 'random' || params[:order].blank?
           seed = params[:random_seed] || session[:random_seed] || rand(-100000..100000)
-          params[:random_seed] ||= Float(seed) rescue 0
+          params[:random_seed] = Float(seed) / 1000000 rescue 0
+          session[:random_seed] = params[:random_seed]
         else
           params[:random_seed] = nil
         end

spec/features/budgets/investments_spec.rb

@@ -610,7 +610,15 @@ feature 'Budget Investments' do
       end
 
       expect(@first_user_investments_order).to eq(@second_user_investments_order)
+    scenario "Convert seed to a value small enough for the modulus function to return investments in random order", :focus do
+      12.times { |i| create(:budget_investment, heading: heading, id: i) }
 
+      visit budget_investments_path(budget, heading_id: heading.id, random_seed: '12')
+
+      order = investments_order
+      orderd_by_id = Budget::Investment.order(:id).limit(10).pluck(:title)
+
+      expect(order).to_not eq(orderd_by_id)
     end
 
     def investments_order