Add redirect specs for PaypalController#express

spec/controllers/spree/paypal_controller_spec.rb

@@ -57,6 +57,48 @@ module Spree
       end
     end
 
+    describe "#express" do
+      let(:order) { create(:order_with_distributor) }
+      let(:response) { true }
+      let(:provider_success_url) { "https://test.com/success" }
+      let(:response_mock) { double(:response, success?: response, errors: [] ) }
+      let(:provider_mock) { double(:provider, build_set_express_checkout: true,
+                                              set_express_checkout: response_mock,
+                                              express_checkout_url: provider_success_url) }
+
+      before do
+        allow(controller).to receive(:current_order) { order }
+        allow(controller).to receive(:provider) { provider_mock }
+        allow(controller).to receive(:express_checkout_request_details) { {} }
+      end
+
+      context "when processing is successful" do
+        it "redirects to a success URL generated by the payment provider" do
+          expect(spree_post :express).to redirect_to provider_success_url
+        end
+      end
+
+      context "when processing fails" do
+        let(:response) { false }
+
+        it "redirects to checkout_state_path with a flash error" do
+          expect(spree_post :express).to redirect_to checkout_state_path(:payment)
+          expect(flash[:error]).to eq "PayPal failed. "
+        end
+      end
+
+      context "when a SocketError is encountered during processing" do
+        before do
+          allow(response_mock).to receive(:success?).and_raise(SocketError)
+        end
+
+        it "redirects to checkout_state_path with a flash error" do
+          expect(spree_post :express).to redirect_to checkout_state_path(:payment)
+          expect(flash[:error]).to eq "Could not connect to PayPal."
+        end
+      end
+    end
+
     describe '#expire_current_order' do
       it 'empties the order_id of the session' do
         expect(session).to receive(:[]=).with(:order_id, nil)