Dry::Initializer::ModelCoercer (instead of dry-initializer-rails)

model_coercer.rb

# frozen_string_literal: true

module Dry
  module Initializer
    # @example
    #   class CreateOrder
    #     extend Dry::Initializer
    #
    #     # Params and options
    #     param  :customer, model: 'Customer' # use either a name
    #     option :product,  model: Product    # or a class
    #
    #     def call
    #       Order.create customer: customer, product: product
    #     end
    #   end
    #
    # @api private
    class ModelCoercer
      # @param model [Class,ActiveRecord::Relation]
      # @param find_by [Symbol,String]
      # @param options [Hash]
      # @return [Hash] unchanged options or options with added type coercion
      def self.call(model: nil, find_by: :id, **options)
        return options unless model
        options.merge(type: new(model, find_by))
      end

      # @param model [Class,ActiveRecord::Relation]
      # @param find_by [Symbol,String]
      # @return [self]
      def initialize(model, find_by = :id)
        @model = model.is_a?(String) ? model.safe_constantize : model
        @find_by = find_by
      end

      # @param value [ActiveRecord::Base,Integer,String]
      # @return [ActiveRecord::Base]
      def call(value)
        return value if value.nil? || value.is_a?(klass)
        @model.find_by! @find_by => value
      end

      private def klass
        @model.is_a?(ActiveRecord::Relation) ? @model.klass : @model
      end
    end
  end
end