Customers controller serializes data for json requests, just renders view without data for html

app/controllers/admin/customers_controller.rb

@@ -1,4 +1,28 @@
 module Admin
   class CustomersController < ResourceController
+    before_filter :load_managed_shops, only: :index, if: :html_request?
+
+    def index
+      respond_to do |format|
+        format.html
+        format.json do
+          render json: ActiveModel::ArraySerializer.new( @collection,
+            each_serializer: Api::Admin::CustomerSerializer, spree_current_user: spree_current_user
+          ).to_json
+        end
+      end
+    end
+
+    private
+
+    def collection
+      return Customer.where("1=0") if html_request? || params[:enterprise_id].nil?
+      enterprise = Enterprise.managed_by(spree_current_user).find_by_id(params[:enterprise_id])
+      Customer.of(enterprise)
+    end
+
+    def load_managed_shops
+      @shops = Enterprise.managed_by(spree_current_user).is_distributor
+    end
   end
 end

app/controllers/spree/admin/base_controller_decorator.rb

@@ -58,4 +58,8 @@ Spree::Admin::BaseController.class_eval do
         "Until you set these up, customers will not be able to shop at this hub."
     end
   end
+
+  def html_request?
+    request.format.html?
+  end
 end

app/serializers/api/admin/customer_serializer.rb

@@ -0,0 +1,3 @@
+class Api::Admin::CustomerSerializer < ActiveModel::Serializer
+  attributes :id, :email, :enterprise_id, :user_id, :code
+end

spec/controllers/admin/customers_controller_spec.rb

@@ -0,0 +1,62 @@
+describe Admin::CustomersController, type: :controller do
+  include AuthenticationWorkflow
+
+  describe "index" do
+    let(:enterprise) { create(:distributor_enterprise) }
+    let(:another_enterprise) { create(:distributor_enterprise) }
+
+    context "html" do
+      before do
+        controller.stub spree_current_user: enterprise.owner
+      end
+
+      it "returns an empty @collection" do
+        spree_get :index, format: :html
+        expect(assigns(:collection)).to eq []
+      end
+    end
+
+    context "json" do
+      let!(:customer) { create(:customer, enterprise: enterprise) }
+
+      context "where I manage the enterprise" do
+        before do
+          controller.stub spree_current_user: enterprise.owner
+        end
+
+        context "and enterprise_id is given in params" do
+          let(:params) { { format: :json, enterprise_id: enterprise.id } }
+
+          it "scopes @collection to customers of that enterprise" do
+            spree_get :index, params
+            expect(assigns(:collection)).to eq [customer]
+          end
+
+          it "serializes the data" do
+            expect(ActiveModel::ArraySerializer).to receive(:new)
+            spree_get :index, params
+          end
+        end
+
+        context "and enterprise_id is not given in params" do
+          it "returns an empty collection" do
+            spree_get :index, format: :json
+            expect(assigns(:collection)).to eq []
+          end
+        end
+      end
+
+      context "and I do not manage the enterprise" do
+        before do
+          controller.stub spree_current_user: another_enterprise.owner
+        end
+
+        it "returns an empty collection" do
+          spree_get :index, format: :json
+          expect(assigns(:collection)).to eq []
+        end
+      end
+    end
+
+  end
+end