Refactor data migration to use data sets

db/migrate/20220105085729_split_customers_name.rb

@@ -1,29 +1,38 @@
+require 'concerns/address_display'
+require 'spree/address'
+
 class SplitCustomersName < ActiveRecord::Migration[6.1]
-  class Customer < ActiveRecord::Base
+  class Customer < ApplicationRecord
+    belongs_to :bill_address, class_name: "Spree::Address"
   end
 
-  def change
+  def up
     add_column :customers, :first_name, :string, null: false, default: ""
     add_column :customers, :last_name, :string, null: false, default: ""
     rename_column :customers, :name, :backup_name
-    reversible do |dir|
-      dir.up { migrate_customer_name_data }
-    end
+
+    migrate_customer_name_data!
   end
 
-  def migrate_customer_name_data
-    Customer.includes(:bill_address).find_each do |customer|
+  def down
+    remove_column :customers, :first_name
+    remove_column :customers, :last_name
+    rename_column :customers, :backup_name, :name
+  end
+
+  def migrate_customer_name_data!
+    Customer.includes(:bill_address).where.not(bill_address_id: nil).find_each do |customer|
       bill_address = customer.bill_address
 
-      if bill_address.present? && bill_address.firstname.present? && bill_address.lastname?
-        customer.first_name = bill_address.firstname.strip
-        customer.last_name = bill_address.lastname.strip
-      else
-        first_name, last_name = customer.backup_name.strip.split(' ', 2)
-        customer.first_name = first_name
-        customer.last_name = last_name
-      end
+      customer.first_name = bill_address.firstname.strip
+      customer.last_name = bill_address.lastname.strip
+      customer.save
+    end
 
+    Customer.where(first_name: "", last_name: "").where.not(backup_name: [nil, ""]).find_each do |customer|
+      first_name, last_name = customer.backup_name.split(' ', 2)
+      customer.first_name = first_name
+      customer.last_name = last_name.to_s
       customer.save
     end
   end