Add some basic test coverage to exchange_products_controller and exchange_products_renderer

spec/controllers/api/exchange_products_controller_spec.rb

@@ -4,31 +4,46 @@ module Api
   describe ExchangeProductsController, type: :controller do
     include AuthenticationWorkflow
 
-    let!(:order_cycle) { create(:order_cycle) }
-    let!(:coordinator) { order_cycle.coordinator }
+    let(:order_cycle) { create(:order_cycle) }
+    let(:exchange) { order_cycle.exchanges.incoming.first }
+    let(:coordinator) { order_cycle.coordinator }
+
+    let!(:renderer) { ExchangeProductsRenderer.new(order_cycle, coordinator.owner) }
 
     before do
       allow(controller).to receive_messages spree_current_user: coordinator.owner
+      allow(ExchangeProductsRenderer).to receive(:new) { renderer }
+      allow(renderer).
+        to receive(:exchange_products).
+        with(exchange.incoming, exchange.sender).
+        and_return(products_relation)
     end
 
     describe "#index" do
-      describe "for incoming exchanges" do
-        it "loads data" do
-          exchange = order_cycle.exchanges.incoming.first
-          spree_get :index, exchange_id: exchange.id
+      describe "when the product list is empty" do
+        let(:products_relation) { Spree::Product.where("1=0") }
 
-          expect(json_response["products"].first["supplier_name"]).to eq exchange.variants.first.product.supplier.name
+        it "handles it gracefully" do
+          spree_get :index, exchange_id: exchange.id
+          expect(json_response["products"].length).to eq 0
         end
       end
 
-      describe "for outgoing exchanges" do
-        it "loads data" do
-          exchange = order_cycle.exchanges.outgoing.first
-          spree_get :index, exchange_id: exchange.id
+      describe "when a product is returned" do
+        let(:products_relation) { Spree::Product.where(id: exchange.variants.first.product.id) }
 
-          suppliers = [exchange.variants[0].product.supplier.name, exchange.variants[1].product.supplier.name]
-          expect(suppliers).to include json_response["products"].first["supplier_name"]
-          expect(suppliers).to include json_response["products"].second["supplier_name"]
+        describe "when an exchange id param is provided" do
+          it "uses exchange order_cycle, incoming and enterprise to fetch products" do
+            spree_get :index, exchange_id: exchange.id, order_cycle_id: 666, enterprise_id: 666, incoming: false
+            expect(json_response["products"].first["supplier_name"]).to eq exchange.variants.first.product.supplier.name
+          end
+        end
+
+        describe "when an exchange id param is not provided" do
+          it "uses params order_cycle, incoming and enterprise to fetch products" do
+            spree_get :index, order_cycle_id: order_cycle.id, enterprise_id: exchange.sender_id, incoming: true
+            expect(json_response["products"].first["supplier_name"]).to eq exchange.variants.first.product.supplier.name
+          end
         end
       end
     end

spec/services/exchange_products_renderer_spec.rb

@@ -0,0 +1,29 @@
+require "spec_helper"
+
+describe ExchangeProductsRenderer do
+  let(:order_cycle) { create(:order_cycle) }
+  let(:coordinator) { order_cycle.coordinator }
+  let(:renderer) { described_class.new(order_cycle, coordinator.owner) }
+
+  describe "#exchange_products" do
+    describe "for an incoming exchange" do
+      it "loads products" do
+        exchange = order_cycle.exchanges.incoming.first
+        products = renderer.exchange_products(true, exchange.sender)
+
+        expect(products.first.supplier.name).to eq exchange.variants.first.product.supplier.name
+      end
+    end
+
+    describe "for an outgoing exchange" do
+      it "loads products" do
+        exchange = order_cycle.exchanges.outgoing.first
+        products = renderer.exchange_products(false, exchange.receiver)
+
+        suppliers = [exchange.variants[0].product.supplier.name, exchange.variants[1].product.supplier.name]
+        expect(suppliers).to include products.first.supplier.name
+        expect(suppliers).to include products.second.supplier.name
+      end
+    end
+  end
+end