app/controllers/finance/ordergroups_controller.rb

@@ -11,7 +11,10 @@ class Finance::OrdergroupsController < Finance::BaseController
     @ordergroups = Ordergroup.undeleted.order(sort)
     @ordergroups = @ordergroups.include_transaction_class_sum
     @ordergroups = @ordergroups.where('groups.name LIKE ?', "%#{params[:query]}%") unless params[:query].nil?
-
     @ordergroups = @ordergroups.page(params[:page]).per(@per_page)
+
+    @total_balances = FinancialTransactionClass.sorted.each_with_object({}) do |c, tmp|
+      tmp[c.id] = c.financial_transactions.reduce(0) { | sum, t | sum + t.amount }
+    end
   end
 end

app/views/finance/ordergroups/_ordergroups.html.haml

@@ -22,3 +22,12 @@
         %td
           = link_to t('.new_transaction'), new_finance_ordergroup_transaction_path(ordergroup), class: 'btn btn-mini'
           = link_to t('.account_statement'), finance_ordergroup_transactions_path(ordergroup), class: 'btn btn-mini'
+  %thead
+    %tr
+      %th= t 'Total'
+      %th
+      - FinancialTransactionClass.sorted.each do |c|
+        - name = FinancialTransactionClass.has_multiple_classes ? c.display : heading_helper(Ordergroup, :account_balance)
+        %th.numeric= format_currency @total_balances[c.id]
+      %th.numeric
+        = format_currency @total_balances.values.reduce(:+)

spec/controllers/finance/ordergroups_controller_spec.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Finance::OrdergroupsController do
+  let(:user) { create(:user, :role_finance, :role_orders, :ordergroup) }
+  let(:fin_trans_type1) { create(:financial_transaction_type) }
+  let(:fin_trans_type2) { create(:financial_transaction_type) }
+  let(:fin_trans1) do
+    create(:financial_transaction,
+           user: user,
+           ordergroup: user.ordergroup,
+           financial_transaction_type: fin_trans_type1)
+  end
+  let(:fin_trans2) do
+    create(:financial_transaction,
+           user: user,
+           ordergroup: user.ordergroup,
+           financial_transaction_type: fin_trans_type1)
+  end
+  let(:fin_trans3) do
+    create(:financial_transaction,
+           user: user,
+           ordergroup: user.ordergroup,
+           financial_transaction_type: fin_trans_type2)
+  end
+
+  before { login user }
+
+  describe 'GET index' do
+    before do
+      fin_trans1
+      fin_trans2
+      fin_trans3
+    end
+
+    it 'renders index page' do
+      get_with_defaults :index
+      expect(response).to have_http_status(:success)
+      expect(response).to render_template('finance/ordergroups/index')
+    end
+
+    it 'calculates total balance sums correctly' do
+      get_with_defaults :index
+      expect(assigns(:total_balances).size).to eq(2)
+      expect(assigns(:total_balances)[fin_trans_type1.id]).to eq(fin_trans1.amount + fin_trans2.amount)
+      expect(assigns(:total_balances)[fin_trans_type2.id]).to eq(fin_trans3.amount)
+    end
+  end
+end