merge automatic group order invoice generation

see https://github.com/foodcoops/foodsoft/pull/907 for reference
and original work by viehlieb

Co-authored-by: viehlieb <pf@pragma-shift.net>

fix PDF Pdf

make explicit deposit in invoices work

add ordergroupname to invoice file name

mark bold sum for vat exempt foodcoops

download multiple group order invoice as zip

spec/models/group_order_invoice_spec.rb

@@ -0,0 +1,59 @@
+require_relative '../spec_helper'
+
+describe GroupOrderInvoice do
+  let(:user) { create :user, groups: [create(:ordergroup)] }
+  let(:supplier) { create :supplier }
+  let(:article) { create :article, supplier: supplier }
+  let(:order) { create :order }
+  let(:group_order) { create :group_order, order: order, ordergroup: user.ordergroup }
+
+  describe 'erroneous group order invoice' do
+    let(:goi) { create :group_order_invoice, group_order_id: group_order.id }
+    it 'does not create group order invoice if tax_number not set' do
+      expect { goi }.to raise_error(ActiveRecord::RecordInvalid, /.*/)
+    end
+  end
+
+  describe 'valid group order invoice' do
+    before do
+      FoodsoftConfig[:contact][:tax_number] = 123_457_8
+    end
+
+    invoice_number1 = Time.now.strftime("%Y%m%d") + '0001'
+    invoice_number2 = Time.now.strftime("%Y%m%d") + '0002'
+
+    let(:user2) { create :user, groups: [create(:ordergroup)] }
+
+    let(:goi1) { create :group_order_invoice, group_order_id: group_order.id }
+    let(:goi2) { create :group_order_invoice, group_order_id: group_order.id }
+
+    let(:group_order2) { create :group_order, order: order, ordergroup: user2.ordergroup }
+
+    let(:goi3) { create :group_order_invoice, group_order_id: group_order2.id }
+    let(:goi4) { create :group_order_invoice, group_order_id: group_order2.id, invoice_number: invoice_number1 }
+
+    it 'creates group order invoice if tax_number is set' do
+      expect(goi1).to be_valid
+    end
+
+    it 'sets invoice_number according to date' do
+      number = Time.now.strftime("%Y%m%d") + '0001'
+      expect(goi1.invoice_number).to eq(number.to_i)
+    end
+
+    it 'fails to create if group_order_id is used multiple times for creation' do
+      expect(goi1.group_order.id).to eq(group_order.id)
+      expect { goi2 }.to raise_error(ActiveRecord::RecordNotUnique)
+    end
+
+    it 'creates two different group order invoice with different invoice_numbers' do
+      expect(goi1.invoice_number).to eq(invoice_number1.to_i)
+      expect(goi3.invoice_number).to eq(invoice_number2.to_i)
+    end
+
+    it 'fails to create two different group order invoice with same invoice_numbers' do
+      goi1
+      expect { goi4 }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+  end
+end