Make state machine modules auto-loadable

.rubocop_todo.yml

@@ -512,7 +512,6 @@ Style/AccessorGrouping:
     - "core/app/models/spree/order.rb"
     - "core/lib/generators/spree/dummy/dummy_generator.rb"
     - "core/lib/spree/core/search/base.rb"
-    - "core/lib/spree/core/state_machines/order.rb"
     - "core/lib/spree/core/stock_configuration.rb"
 
 # Offense count: 1

core/app/models/spree/core/state_machines/inventory_unit.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Spree
+  module Core
+    class StateMachines
+      # Inventory Units' state machine
+      #
+      # for each event the following instance methods are dynamically implemented:
+      #   #<event_name>
+      #   #<event_name>!
+      #   #can_<event_name>?
+      #
+      # for each state the following instance methods are implemented:
+      #   #<state_name>?
+      #
+      module InventoryUnit
+        extend ActiveSupport::Concern
+
+        included do
+          state_machine initial: :on_hand do
+            event :fill_backorder do
+              transition to: :on_hand, from: :backordered
+            end
+            after_transition on: :fill_backorder, do: :fulfill_order
+
+            event :ship do
+              transition to: :shipped, if: :allow_ship?
+            end
+
+            event :return do
+              transition to: :returned, from: :shipped
+            end
+
+            event :cancel do
+              transition to: :canceled, from: ::Spree::InventoryUnit::CANCELABLE_STATES.map(&:to_sym)
+            end
+          end
+        end
+      end
+    end
+  end
+end

core/app/models/spree/core/state_machines/order.rb

@@ -0,0 +1,250 @@
+# frozen_string_literal: true
+
+module Spree
+  module Core
+    class StateMachines
+      module Order
+        def self.included(klass)
+          klass.extend ClassMethods
+        end
+
+        module ClassMethods
+          attr_accessor :previous_states
+          attr_writer :next_event_transitions, :checkout_steps, :removed_transitions
+
+          def checkout_flow(&block)
+            if block_given?
+              @checkout_flow = block
+              define_state_machine!
+            else
+              @checkout_flow
+            end
+          end
+
+          def define_state_machine!
+            self.checkout_steps = {}
+            self.next_event_transitions = []
+            self.previous_states = [:cart]
+            self.removed_transitions = []
+
+            # Build the checkout flow using the checkout_flow defined either
+            # within the Order class, or a decorator for that class.
+            #
+            # This method may be called multiple times depending on if the
+            # checkout_flow is re-defined in a decorator or not.
+            instance_eval(&checkout_flow)
+
+            klass = self
+
+            # To avoid multiple occurrences of the same transition being defined
+            # On first definition, state_machines will not be defined
+            state_machines.clear if respond_to?(:state_machines)
+            state_machine :state, initial: :cart, use_transactions: false do
+              klass.next_event_transitions.each { |state| transition(state.merge(on: :next)) }
+
+              # Persist the state on the order
+              after_transition do |order, transition|
+                # Hard to say if this is really necessary, it was introduced in this commit:
+                # https://github.com/mamhoff/solidus/commit/fa1d66c42e4c04ee7cd1c20d87e4cdb74a226d3d
+                # But it seems to be harmless, so we'll keep it for now.
+                order.state = order.state # rubocop:disable Lint/SelfAssignment
+
+                order.state_changes.create(
+                  previous_state: transition.from,
+                  next_state:     transition.to,
+                  name:           'order',
+                  user_id:        order.user_id
+                )
+                order.save
+              end
+
+              event :cancel do
+                transition to: :canceled, if: :allow_cancel?, from: :complete
+              end
+
+              event :return do
+                transition to: :returned, from: [:complete, :awaiting_return], if: :all_inventory_units_returned?
+              end
+
+              event :resume do
+                transition to: :resumed, from: :canceled, if: :canceled?
+              end
+
+              event :authorize_return do
+                transition to: :awaiting_return, from: :complete
+              end
+
+              event :complete do
+                transition to: :complete, from: klass.checkout_steps.keys.last
+              end
+
+              if states[:payment]
+                event :payment_failed do
+                  transition to: :payment, from: :confirm
+                end
+
+                after_transition to: :complete, do: :add_payment_sources_to_wallet
+                before_transition to: :payment, do: :add_default_payment_from_wallet
+                before_transition to: :payment, do: :ensure_billing_address
+
+                before_transition to: :confirm, do: :add_store_credit_payments
+
+                # see also process_payments_before_complete below which needs to
+                # be added in the correct sequence.
+              end
+
+              before_transition from: :cart, do: :ensure_line_items_present
+
+              if states[:address]
+                before_transition to: :address, do: :assign_default_user_addresses
+                before_transition from: :address, do: :persist_user_address!
+              end
+
+              if states[:delivery]
+                before_transition to: :delivery, do: :ensure_shipping_address
+                before_transition to: :delivery, do: :create_proposed_shipments
+                before_transition to: :delivery, do: :ensure_available_shipping_rates
+              end
+
+              before_transition to: :resumed, do: :ensure_line_item_variants_are_not_deleted
+              before_transition to: :resumed, do: :validate_line_item_availability
+
+              # Sequence of before_transition to: :complete
+              # calls matter so that we do not process payments
+              # until validations have passed
+              before_transition to: :complete, do: :validate_line_item_availability
+              before_transition to: :complete, do: :ensure_promotions_eligible
+              before_transition to: :complete, do: :ensure_line_item_variants_are_not_deleted
+              before_transition to: :complete, do: :ensure_inventory_units
+              if states[:payment]
+                before_transition to: :complete, do: :process_payments_before_complete
+              end
+
+              after_transition to: :complete, do: :finalize
+              after_transition to: :resumed,  do: :after_resume
+              after_transition to: :canceled, do: :after_cancel
+
+              after_transition from: any - :cart, to: any - [:confirm, :complete] do |order|
+                order.recalculate
+              end
+
+              after_transition do |order, transition|
+                order.logger.debug "Order #{order.number} transitioned from #{transition.from} to #{transition.to} via #{transition.event}"
+              end
+
+              after_failure do |order, transition|
+                order.logger.debug "Order #{order.number} halted transition on event #{transition.event} state #{transition.from}: #{order.errors.full_messages.join}"
+              end
+            end
+          end
+
+          def go_to_state(name, options = {})
+            checkout_steps[name] = options
+            previous_states.each do |state|
+              add_transition({ from: state, to: name }.merge(options))
+            end
+            if options[:if]
+              previous_states << name
+            else
+              self.previous_states = [name]
+            end
+          end
+
+          def insert_checkout_step(name, options = {})
+            before = options.delete(:before)
+            after = options.delete(:after) unless before
+            after = checkout_steps.keys.last unless before || after
+
+            cloned_steps = checkout_steps.clone
+            cloned_removed_transitions = removed_transitions.clone
+            checkout_flow do
+              cloned_steps.each_pair do |key, value|
+                go_to_state(name, options) if key == before
+                go_to_state(key, value)
+                go_to_state(name, options) if key == after
+              end
+              cloned_removed_transitions.each do |transition|
+                remove_transition(transition)
+              end
+            end
+          end
+
+          def remove_checkout_step(name)
+            cloned_steps = checkout_steps.clone
+            cloned_removed_transitions = removed_transitions.clone
+            checkout_flow do
+              cloned_steps.each_pair do |key, value|
+                go_to_state(key, value) unless key == name
+              end
+              cloned_removed_transitions.each do |transition|
+                remove_transition(transition)
+              end
+            end
+          end
+
+          def remove_transition(options = {})
+            removed_transitions << options
+            next_event_transitions.delete(find_transition(options))
+          end
+
+          def find_transition(options = {})
+            return nil if options.nil? || !options.include?(:from) || !options.include?(:to)
+
+            next_event_transitions.detect do |transition|
+              transition[options[:from].to_sym] == options[:to].to_sym
+            end
+          end
+
+          def next_event_transitions
+            @next_event_transitions ||= []
+          end
+
+          def checkout_steps
+            @checkout_steps ||= {}
+          end
+
+          def checkout_step_names
+            checkout_steps.keys
+          end
+
+          def add_transition(options)
+            next_event_transitions << { options.delete(:from) => options.delete(:to) }.merge(options)
+          end
+
+          def removed_transitions
+            @removed_transitions ||= []
+          end
+        end
+
+        def checkout_steps
+          steps = self.class.checkout_steps.each_with_object([]) { |(step, options), checkout_steps|
+            next if options.include?(:if) && !options[:if].call(self)
+
+            checkout_steps << step
+          }.map(&:to_s)
+          # Ensure there is always a complete step
+          steps << "complete" unless steps.include?("complete")
+          steps
+        end
+
+        def has_checkout_step?(step)
+          step.present? && checkout_steps.include?(step)
+        end
+
+        def passed_checkout_step?(step)
+          has_checkout_step?(step) && checkout_step_index(step) < checkout_step_index(state)
+        end
+
+        def checkout_step_index(step)
+          checkout_steps.index(step).to_i
+        end
+
+        def can_go_to_state?(state)
+          return false unless has_checkout_step?(self.state) && has_checkout_step?(state)
+
+          checkout_step_index(state) > checkout_step_index(self.state)
+        end
+      end
+    end
+  end
+end

core/app/models/spree/core/state_machines/payment.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+module Spree
+  module Core
+    class StateMachines
+      # Payments' state machine
+      #
+      # for each event the following instance methods are dynamically implemented:
+      #   #<event_name>
+      #   #<event_name>!
+      #   #can_<event_name>?
+      #
+      # for each state the following instance methods are implemented:
+      #   #<state_name>?
+      #
+      module Payment
+        extend ActiveSupport::Concern
+
+        included do
+          state_machine initial: :checkout do
+            # With card payments, happens before purchase or authorization happens
+            #
+            # Setting it after creating a profile and authorizing a full amount will
+            # prevent the payment from being authorized again once Order transitions
+            # to complete
+            event :started_processing do
+              transition from: [:checkout, :pending, :completed, :processing], to: :processing
+            end
+            # When processing during checkout fails
+            event :failure do
+              transition from: [:pending, :processing], to: :failed
+            end
+            # With card payments this represents authorizing the payment
+            event :pend do
+              transition from: [:checkout, :processing], to: :pending
+            end
+            # With card payments this represents completing a purchase or capture transaction
+            event :complete do
+              transition from: [:processing, :pending, :checkout], to: :completed
+            end
+            event :void do
+              transition from: [:pending, :processing, :completed, :checkout], to: :void
+            end
+            # when the card brand isnt supported
+            event :invalidate do
+              transition from: [:checkout], to: :invalid
+            end
+
+            after_transition do |payment, transition|
+              payment.state_changes.create!(
+                previous_state: transition.from,
+                next_state:     transition.to,
+                name:           'payment'
+              )
+            end
+          end
+        end
+      end
+    end
+  end
+end

core/app/models/spree/core/state_machines/reimbursement.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Spree
+  module Core
+    class StateMachines
+      # Reimbursement' state machine
+      #
+      # for each event the following instance methods are dynamically implemented:
+      #   #<event_name>
+      #   #<event_name>!
+      #   #can_<event_name>?
+      #
+      # for each state the following instance methods are implemented:
+      #   #<state_name>?
+      #
+      module Reimbursement
+        extend ActiveSupport::Concern
+
+        included do
+          state_machine :reimbursement_status, initial: :pending do
+            event :errored do
+              transition to: :errored, from: [:pending, :errored]
+            end
+
+            event :reimbursed do
+              transition to: :reimbursed, from: [:pending, :errored]
+            end
+          end
+        end
+      end
+    end
+  end
+end