use Customer#with_completed_orders on the customers listing endpoints

app/controllers/admin/customers_controller.rb

@@ -83,7 +83,7 @@ def collection
     def customers
       return @customers if @customers.present?
 
-      @customers = Customer.managed_by(spree_current_user)
+      @customers = Customer.with_completed_orders.managed_by(spree_current_user)
       return @customers if params[:enterprise_id].blank?
 
       @customers = @customers.where(enterprise_id: params[:enterprise_id])

app/controllers/api/v0/customers_controller.rb

@@ -6,7 +6,7 @@ class CustomersController < Api::V0::BaseController
       skip_authorization_check only: :index
 
       def index
-        @customers = current_api_user.customers
+        @customers = current_api_user.customers.with_completed_orders
         render json: @customers, each_serializer: CustomerSerializer
       end
 

app/controllers/api/v1/customers_controller.rb

@@ -80,7 +80,7 @@ def search_customers
       end
 
       def visible_customers
-        Customer.managed_by(current_api_user)
+        Customer.with_completed_orders.managed_by(current_api_user)
       end
 
       def customer_params

app/models/customer.rb

@@ -36,6 +36,7 @@ class Customer < ApplicationRecord
 
   scope :of, ->(enterprise) { where(enterprise_id: enterprise) }
   scope :managed_by, ->(user) { user&.persisted? ? where(user: user).or(of(Enterprise.managed_by(user))) : none }
+  scope :with_completed_orders, -> { joins(:orders).merge(Spree::Order.complete).distinct }
 
   before_create :associate_user
 

spec/models/customer_spec.rb

@@ -111,5 +111,21 @@
         expect(Customer.managed_by(guest)).to match_array []
       end
     end
+
+    context 'with_completed_orders' do
+      let!(:customer) { create(:customer) }
+      let!(:customer2) { create(:customer) }
+      let!(:customer3) { create(:customer) }
+      let!(:customer4) { create(:customer) }
+
+      let!(:order_ready_for_details) { create(:order_ready_for_details, customer: customer) }
+      let!(:order_ready_for_payment){ create(:order_ready_for_payment, customer: customer2) }
+      # let!(:order_ready_for_confirmation) { create(:order_ready_for_confirmation, state: :confirmation, customer: customer3) }
+      let!(:completed_order) {create(:completed_order_with_totals, customer: customer4)}
+
+      it 'returns customers with completed orders' do
+        expect(Customer.with_completed_orders).to match_array [customer4]
+      end
+    end
   end
 end