Create Api::BaseController to allow use of ActiveModelSerializers

Also add index action to Api::CustomersController

spec/controllers/api/customers_controller_spec.rb

@@ -3,13 +3,32 @@ require 'spec_helper'
 module Api
   describe CustomersController, type: :controller do
     include AuthenticationWorkflow
+    include OpenFoodNetwork::ApiHelper
     render_views
 
     let(:user) { create(:user) }
-    let(:customer) { create(:customer, user: user) }
-    let(:params) { { format: :json, id: customer.id, customer: { code: '123' } } }
+
+    describe "index" do
+      let!(:customer1) { create(:customer) }
+      let!(:customer2) { create(:customer) }
+
+      before do
+        user.customers << customer1
+        allow(controller).to receive(:spree_current_user) { user }
+      end
+
+      it "lists customers associated with the current user" do
+        spree_get :index
+        expect(response.status).to eq 200
+        expect(json_response.length).to eq 1
+        expect(json_response.first[:id]).to eq customer1.id
+      end
+    end
 
     describe "#update" do
+      let(:customer) { create(:customer, user: user) }
+      let(:params) { { format: :json, id: customer.id, customer: { code: '123' } } }
+
       context "as a user who is not associated with the customer" do
         before do
           allow(controller).to receive(:spree_current_user) { create(:user) }
@@ -30,7 +49,7 @@ module Api
           it "returns the id of the updated customer" do
             spree_post :update, params
             expect(response.status).to eq 200
-            expect(response.body).to eq customer.id.to_s
+            expect(json_response[:id]).to eq customer.id
           end
         end
 
@@ -40,7 +59,7 @@ module Api
           it "returns a 422, with an error message" do
             spree_post :update, params
             expect(response.status).to be 422
-            expect(JSON.parse(response.body)['error']).to be
+            expect(json_response[:error]).to be
           end
         end
       end