Add dummy calculator

This implements the interface required by Solidus, however it currently
just reports no taxes.

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/super_good/solidus_taxjar/tax_calculator.rb b/lib/super_good/solidus_taxjar/tax_calculator.rb
new file mode 100644
index 0000000..e2a398e
--- /dev/null
+++ b/lib/super_good/solidus_taxjar/tax_calculator.rb
@@ -0,0 +1,29 @@
+module SuperGood
+  module SolidusTaxJar
+    class TaxCalculator
+      def initialize(order)
+        @order = order
+      end
+
+      def calculate
+        Spree::Tax::OrderTax.new(
+          order_id: order.id,
+          line_item_taxes: line_item_rates,
+          shipment_taxes: shipment_rates
+        )
+      end
+
+      private
+
+      attr_reader :order
+
+      def line_item_rates
+        []
+      end
+
+      def shipment_rates
+        []
+      end
+    end
+  end
+end