diff --git a/.rubocop_manual_todo.yml b/.rubocop_manual_todo.yml
index 94fdd0bd31..c5b16934f0 100644
--- a/.rubocop_manual_todo.yml
+++ b/.rubocop_manual_todo.yml
@@ -391,6 +391,7 @@ Metrics/AbcSize:
   - app/models/spree/order_decorator.rb
   - app/models/spree/payment_decorator.rb
   - app/models/spree/product_decorator.rb
+  - app/models/spree/shipment.rb
   - app/models/spree/taxon_decorator.rb
   - app/models/spree/tax_rate_decorator.rb
   - app/serializers/api/admin/enterprise_serializer.rb
@@ -400,6 +401,9 @@ Metrics/AbcSize:
   - app/services/create_order_cycle.rb
   - app/services/order_cycle_form.rb
   - app/services/order_syncer.rb
+  - engines/order_management/app/services/order_management/stock/estimator.rb
+  - engines/order_management/app/services/order_management/stock/package.rb
+  - engines/order_management/app/services/order_management/stock/packer.rb
   - engines/order_management/app/services/order_management/subscriptions/validator.rb
   - lib/active_merchant/billing/gateways/stripe_decorator.rb
   - lib/active_merchant/billing/gateways/stripe_payment_intents.rb
@@ -457,6 +461,7 @@ Metrics/BlockLength:
     "scenario"
   ]
   Exclude:
+  - app/models/spree/shipment.rb
   - lib/tasks/data.rake
   - spec/controllers/spree/admin/invoices_controller_spec.rb
   - spec/factories/enterprise_factory.rb
@@ -496,6 +501,7 @@ Metrics/CyclomaticComplexity:
   - app/models/spree/product_decorator.rb
   - app/models/variant_override_set.rb
   - app/services/cart_service.rb
+  - engines/order_management/app/services/order_management/stock/estimator.rb
   - lib/active_merchant/billing/gateways/stripe_payment_intents.rb
   - lib/discourse/single_sign_on.rb
   - lib/open_food_network/bulk_coop_report.rb
@@ -520,6 +526,7 @@ Metrics/PerceivedComplexity:
   - app/models/spree/ability_decorator.rb
   - app/models/spree/order_decorator.rb
   - app/models/spree/product_decorator.rb
+  - engines/order_management/app/services/order_management/stock/estimator.rb
   - lib/active_merchant/billing/gateways/stripe_payment_intents.rb
   - lib/discourse/single_sign_on.rb
   - lib/open_food_network/bulk_coop_report.rb
@@ -585,11 +592,14 @@ Metrics/MethodLength:
   - app/models/spree/payment_decorator.rb
   - app/models/spree/payment_method_decorator.rb
   - app/models/spree/product_decorator.rb
+  - app/models/spree/shipment.rb
   - app/serializers/api/admin/order_cycle_serializer.rb
   - app/serializers/api/cached_enterprise_serializer.rb
   - app/services/order_cycle_form.rb
   - app/services/permitted_attributes/checkout.rb
   - engines/order_management/app/services/order_management/reports/enterprise_fee_summary/scope.rb
+  - engines/order_management/app/services/order_management/stock/estimator.rb
+  - engines/order_management/app/services/order_management/stock/package.rb
   - lib/active_merchant/billing/gateways/stripe_payment_intents.rb
   - lib/discourse/single_sign_on.rb
   - lib/open_food_network/bulk_coop_report.rb
@@ -652,6 +662,7 @@ Metrics/ClassLength:
   - app/models/product_import/entry_validator.rb
   - app/models/product_import/product_importer.rb
   - app/models/spree/ability_decorator.rb
+  - app/models/spree/shipment.rb
   - app/models/spree/user.rb
   - app/serializers/api/cached_enterprise_serializer.rb
   - app/serializers/api/enterprise_shopfront_serializer.rb
@@ -676,6 +687,7 @@ Metrics/ModuleLength:
   - app/helpers/injection_helper.rb
   - app/helpers/spree/admin/base_helper.rb
   - app/helpers/spree/admin/navigation_helper.rb
+  - engines/order_management/spec/services/order_management/stock/package_spec.rb
   - engines/order_management/spec/services/order_management/subscriptions/estimator_spec.rb
   - engines/order_management/spec/services/order_management/subscriptions/form_spec.rb
   - engines/order_management/spec/services/order_management/subscriptions/proxy_order_syncer_spec.rb
diff --git a/app/models/spree/shipment.rb b/app/models/spree/shipment.rb
index 99d3a57fc0..43b0b586c0 100644
--- a/app/models/spree/shipment.rb
+++ b/app/models/spree/shipment.rb
@@ -67,7 +67,6 @@ module Spree
     end
 
     def to_param
-      number if number
       generate_shipment_number unless number
       number.to_s.to_url.upcase
     end
@@ -136,7 +135,7 @@ module Spree
     alias_method :amount, :cost
 
     def display_cost
-      Spree::Money.new(cost, { currency: currency })
+      Spree::Money.new(cost, currency: currency)
     end
 
     alias_method :display_amount, :display_cost
@@ -146,7 +145,7 @@ module Spree
     end
 
     def display_item_cost
-      Spree::Money.new(item_cost, { currency: currency })
+      Spree::Money.new(item_cost, currency: currency)
     end
 
     def total_cost
@@ -154,7 +153,7 @@ module Spree
     end
 
     def display_total_cost
-      Spree::Money.new(total_cost, { currency: currency })
+      Spree::Money.new(total_cost, currency: currency)
     end
 
     def editable_by?(_user)
diff --git a/engines/order_management/spec/services/order_management/stock/estimator_spec.rb b/engines/order_management/spec/services/order_management/stock/estimator_spec.rb
index 892b7e1cf2..6d14903cbd 100644
--- a/engines/order_management/spec/services/order_management/stock/estimator_spec.rb
+++ b/engines/order_management/spec/services/order_management/stock/estimator_spec.rb
@@ -19,7 +19,7 @@ module OrderManagement
             to receive_message_chain(:calculator, :compute).and_return(4.00)
           allow_any_instance_of(Spree::ShippingMethod).
             to receive_message_chain(:calculator, :preferences).
-            and_return({ currency: order.currency })
+            and_return(currency: order.currency)
           allow_any_instance_of(Spree::ShippingMethod).
             to receive_message_chain(:calculator, :marked_for_destruction?)
 
diff --git a/lib/spree/core/environment.rb b/lib/spree/core/environment.rb
index 443b110c0a..4cd6fb5133 100644
--- a/lib/spree/core/environment.rb
+++ b/lib/spree/core/environment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Spree
   module Core
     class Environment