Add new enterprise customers search API

spec/controllers/spree/admin/search_controller_spec.rb

@@ -31,5 +31,29 @@ describe Spree::Admin::SearchController do
         end
       end
     end
+
+    describe 'searching for customers' do
+      let!(:customer_1) { create(:customer, enterprise: enterprise, email: 'test1@email.com') }
+      let!(:customer_2) { create(:customer, enterprise: enterprise, name: 'test2') }
+      let!(:customer_3) { create(:customer, email: 'test3@email.com') }
+
+      before do
+        spree_get :customers, q: "test", distributor_id: enterprise.id
+        @results = JSON.parse(response.body)
+      end
+
+      describe 'when search query matches the email or name' do
+        it 'returns a list of customers of the enterprise' do
+          expect(@results.size).to eq 2
+
+          expect(@results.find { |c| c['id'] == customer_1.id}).to be_true
+          expect(@results.find { |c| c['id'] == customer_2.id}).to be_true
+        end
+
+        it 'does not return the customer of other enterprises' do
+          expect(@results.find { |c| c['id'] == customer_3.id}).to be_false
+        end
+      end
+    end
   end
 end