Create refund transaction with negative amounts

Refunds in taxjar are transactions that have a negative delta against
the original order. Our API was incorrectly using TaxJar's refund
API by calling it with positive numbers, which would represent the
customer getting paid more, not getting refunded.

2 files changed, 6 insertions, 7 deletions

diff --git a/lib/super_good/solidus_taxjar/api_params.rb b/lib/super_good/solidus_taxjar/api_params.rb
index 2e0e92c..d9d30e5 100644
--- a/lib/super_good/solidus_taxjar/api_params.rb
+++ b/lib/super_good/solidus_taxjar/api_params.rb
@@ -60,9 +60,9 @@ module SuperGood
               transaction_id: reimbursement.number,
               transaction_reference_id: reimbursement.order.number,
               transaction_date: reimbursement.order.completed_at.to_formatted_s(:iso8601),
-              amount: reimbursement.total - additional_taxes,
+              amount: -1 * (reimbursement.total - additional_taxes),
               shipping: 0,
-              sales_tax: additional_taxes
+              sales_tax: -1 * additional_taxes
             )
         end
 
diff --git a/spec/super_good/solidus_taxjar/api_params_spec.rb b/spec/super_good/solidus_taxjar/api_params_spec.rb
index 5ba565b..af8981d 100644
--- a/spec/super_good/solidus_taxjar/api_params_spec.rb
+++ b/spec/super_good/solidus_taxjar/api_params_spec.rb
@@ -328,17 +328,16 @@ RSpec.describe SuperGood::SolidusTaxjar::ApiParams do
         number: "RI123123123",
         order: order,
         return_items: [
-          Spree::ReturnItem.new(additional_tax_total: 0.33),
-          Spree::ReturnItem.new(additional_tax_total: 33.0)
+          Spree::ReturnItem.new(additional_tax_total: 12, amount: 36),
         ],
-        total: 333.33
+        total: 36
       )
     end
 
     it "returns params for creating/updating a refund" do
       expect(subject).to eq({
-        amount: BigDecimal("300.00"),
-        sales_tax: BigDecimal("33.33"),
+        amount: BigDecimal("-24"),
+        sales_tax: BigDecimal("-12"),
         shipping: 0,
         to_city: "Los Angeles",
         to_country: "US",