Transaction transfers, payments, and matching (#883)

* Add transfer model and clean up family snapshot fixtures

* Ignore transfers in income and expense snapshots

* Add transfer validations

* Implement basic transfer matching UI

* Fix merge conflicts

* Add missing translations

* Tweak selection states for transfer types

* Add missing i18n translation

app/helpers/application_form_builder.rb

@@ -25,7 +25,7 @@ class ApplicationFormBuilder < ActionView::Helpers::FormBuilder
   # See `Monetizable` concern, which adds a _money suffix to the attribute name
   # For a monetized field, the setter will always be the attribute name without the _money suffix
   def money_field(method, options = {})
-    money = @object.send(method)
+    money = @object && @object.respond_to?(method) ? @object.send(method) : nil
     raise ArgumentError, "The value of #{method} is not a Money object" unless money.is_a?(Money) || money.nil?
 
     money_amount_method = method.to_s.chomp("_money").to_sym

app/helpers/transactions_helper.rb

@@ -17,4 +17,27 @@ module TransactionsHelper
       content: content
     }
   end
+
+  def unconfirmed_transfer?(transaction)
+    transaction.marked_as_transfer && transaction.transfer.nil?
+  end
+
+  def group_transactions_by_date(transactions)
+    grouped_by_date = {}
+
+    transactions.each do |transaction|
+      if transaction.transfer
+        transfer_date = transaction.transfer.inflow_transaction.date
+        grouped_by_date[transfer_date] ||= { transactions: [], transfers: [] }
+        unless grouped_by_date[transfer_date][:transfers].include?(transaction.transfer)
+          grouped_by_date[transfer_date][:transfers] << transaction.transfer
+        end
+      else
+        grouped_by_date[transaction.date] ||= { transactions: [], transfers: [] }
+        grouped_by_date[transaction.date][:transactions] << transaction
+      end
+    end
+
+    grouped_by_date
+  end
 end

app/helpers/transfers_helper.rb

@@ -0,0 +1,2 @@
+module TransfersHelper
+end