Call #credit with right arguments

app/models/spree/payment_method/taler.rb

@@ -75,10 +75,10 @@ module Spree
         ActiveMerchant::Billing::Response.new(success, message)
       end
 
-      def credit(money, gateway_options)
+      def credit(money, response_code, gateway_options)
         amount = money / 100 # called with cents
         payment = gateway_options[:payment]
-        taler_order = taler_order(id: payment.response_code)
+        taler_order = taler_order(id: response_code)
         status = taler_order.fetch("order_status")
 
         raise "Unsupported action" if status != "paid"

spec/models/spree/payment_method/taler_spec.rb

@@ -69,7 +69,7 @@ RSpec.describe Spree::PaymentMethod::Taler do
         response_code: "taler-order-8",
       )
       expect {
-        response = taler.credit(100, { payment: order.payments[0] })
+        response = taler.credit(100, "taler-order-8", { payment: order.payments[0] })
         expect(response.success?).to eq true
       }.to enqueue_mail(PaymentMailer, :refund_available)
     end
@@ -85,7 +85,7 @@ RSpec.describe Spree::PaymentMethod::Taler do
         response_code: "taler-order-8",
       )
       expect {
-        taler.credit(100, { payment: order.payments[0] })
+        taler.credit(100, "taler-order-8", { payment: order.payments[0] })
       }.to raise_error StandardError, "Unsupported action"
     end
   end

spec/system/admin/payments_taler_spec.rb

@@ -25,7 +25,7 @@ RSpec.describe "Admin -> Order -> Payments" do
     login_as distributor.owner
   end
 
-  it "allows to refund a Taler payment" do
+  it "allows to void a Taler payment" do
     order_status = {
       order_status: "paid",
       contract_terms: {
@@ -49,4 +49,35 @@ RSpec.describe "Admin -> Order -> Payments" do
       expect(page).not_to have_link "Void"
     end
   end
+
+  it "allows to credit a Taler payment" do
+    order_status = {
+      order_status: "paid",
+      contract_terms: {
+        amount: "KUDOS:2",
+      }
+    }
+    order_endpoint = "https://taler.example.com/private/orders/taler-id-1"
+    refund_endpoint = "https://taler.example.com/private/orders/taler-id-1/refund"
+    stub_request(:get, order_endpoint).to_return(body: order_status.to_json)
+    stub_request(:post, refund_endpoint).to_return(body: "{}")
+
+    visit spree.admin_order_payments_path(order.number)
+
+    within row_containing("Taler") do
+      expect(page).to have_text "COMPLETED"
+      expect(page).to have_link "Credit"
+
+      click_link class: "icon-credit"
+
+      expect(page).to have_text "COMPLETED"
+      expect(page).not_to have_link "Credit"
+    end
+
+    # Our payment system creates a new payment to show the credit.
+    within row_containing("$-9.75") do
+      # TODO: don't offer to void a credited amount.
+      expect(page).to have_link "Void"
+    end
+  end
 end