Deprecate the creation of option_values without an option_type

It makes no sense to have dangling option_values without an associated
option_type.

Ref #3309 & #3517

api/app/controllers/spree/api/option_values_controller.rb

@@ -18,6 +18,13 @@ def show
  end
 
  def create
+ Spree::Deprecation.warn <<~MSG unless request.path.include?('option_types')
+ This route is deprecated, as it'll be no longer possible to create an
+ option_value without an associated option_type. Please, use instead:
+
+ POST api/option_types/{option_type_id}/option_values
+ MSG
+
  authorize! :create, Spree::OptionValue
  @option_value = scope.new(option_value_params)
  if @option_value.save

api/config/routes.rb

@@ -54,6 +54,7 @@
  resources :option_types do
  resources :option_values
  end
+ # TODO: Remove :create once option_type is required on Solidus v4.0
  resources :option_values
 
  get '/orders/mine', to: 'orders#mine', as: 'my_orders'

api/openapi/solidus-api.oas.yml

@@ -2544,6 +2544,8 @@ paths:
  $ref: '#/components/responses/unprocessable-entity'
  summary: Create option value
  description: |-
+ **DEPRECATED**: Use *POST /option_types/{option_type_id}/option_values* instead
+
  Creates an option value.
 
  Only users with the `create` permission on `Spree::OptionValue` can perform this action.

api/spec/requests/spree/api/option_values_spec.rb

@@ -110,7 +110,9 @@ module Spree::Api
  expect(option_value.name).to eq("Option Value")
  end
 
- it "can create an option value" do
+ it "can create but deprecates creating an option value without option type" do
+ expect(Spree::Deprecation).to receive(:warn).with(/deprecated/).at_least(:once)
+
  post spree.api_option_values_path, params: { option_value: {
  name: "Option Value",
  presentation: 'option value'

core/app/models/spree/option_value.rb

@@ -2,6 +2,8 @@
 
 module Spree
  class OptionValue < Spree::Base
+ # TODO: Remove optional on Solidus v4.0. Don't forget adding a migration to
+ # enforce at the database layer
  belongs_to :option_type, class_name: 'Spree::OptionType', inverse_of: :option_values, optional: true
  acts_as_list scope: :option_type
 
@@ -13,7 +15,14 @@ class OptionValue < Spree::Base
 
  after_save :touch, if: :saved_changes?
  after_touch :touch_all_variants
+ after_save do
+ Spree::Deprecation.warn <<~MSG if option_type.nil?
+ Having an option_value with no associated option_type will be deprecated
+ on Solidus v4.0
+ MSG
+ end
 
+ # TODO: Remove allow_nil once option_type is required on Solidus v4.0
  delegate :name, :presentation, to: :option_type, prefix: :option_type, allow_nil: true
 
  self.whitelisted_ransackable_attributes = %w[name presentation]

core/spec/models/spree/option_value_spec.rb

@@ -49,4 +49,10 @@
  expect(subject).to eq "Size - S"
  end
  end
+
+ it 'deprecates creating an option_value with no associated option_type' do
+ expect(Spree::Deprecation).to receive(:warn).with(/deprecated/)
+
+ create(:option_value, option_type: nil)
+ end
 end