Patch jsonapi-resources 0.9.12 for Rails 7.2 compatibility

Port fixes from speee PR JSONAPI-Resources#1480 (cerebris/jsonapi-resources):

- Fix Rack 3.0+ status code lookup: :unprocessable_entity was removed
  in favor of :unprocessable_content. Add Error.status_code_for class
  method with fallback mapping.

- Fix ActiveSupport::Deprecation.warn becoming private in Rails 7.2.
  Add JSONAPI.warn_deprecated helper that falls back to Kernel#warn.

- Fix lazy initialization of JSONAPI.configuration to use proper
  accessor pattern.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: lukemelia

lib/jsonapi/configuration.rb

@@ -261,12 +261,26 @@ def default_processor_klass=(default_processor_klass)
   end
 
   class << self
-    attr_accessor :configuration
-  end
+    attr_writer :configuration
 
-  @configuration ||= Configuration.new
+    def configuration
+      @configuration ||= Configuration.new
+    end
+  end
 
   def self.configure
-    yield(@configuration)
+    yield(configuration)
+  end
+
+  # Rails 7.2+ made ActiveSupport::Deprecation.warn a private method
+  # This helper provides backward-compatible deprecation warnings
+  def self.warn_deprecated(message)
+    if defined?(ActiveSupport::Deprecation) && ActiveSupport::Deprecation.respond_to?(:warn)
+      # Rails < 7.2
+      ActiveSupport::Deprecation.warn(message)
+    else
+      # Rails 7.2+ or fallback
+      warn "[DEPRECATION] #{message}"
+    end
   end
 end

lib/jsonapi/error.rb

@@ -2,6 +2,26 @@ module JSONAPI
   class Error
     attr_accessor :title, :detail, :id, :href, :code, :source, :links, :status, :meta
 
+    # Rack 3.0+ deprecated :unprocessable_entity in favor of :unprocessable_content
+    # This mapping ensures compatibility across Rack versions
+    DEPRECATED_STATUS_SYMBOLS = {
+      unprocessable_entity: :unprocessable_content
+    }.freeze
+
+    def self.status_code_for(status_symbol)
+      return nil if status_symbol.nil?
+
+      # Try the symbol directly first
+      code = Rack::Utils::SYMBOL_TO_STATUS_CODE[status_symbol]
+
+      # If not found and it's a deprecated symbol, try the new symbol
+      if code.nil? && DEPRECATED_STATUS_SYMBOLS.key?(status_symbol)
+        code = Rack::Utils::SYMBOL_TO_STATUS_CODE[DEPRECATED_STATUS_SYMBOLS[status_symbol]]
+      end
+
+      code&.to_s
+    end
+
     def initialize(options = {})
       @title          = options[:title]
       @detail         = options[:detail]
@@ -15,7 +35,7 @@ def initialize(options = {})
       @source         = options[:source]
       @links          = options[:links]
 
-      @status         = Rack::Utils::SYMBOL_TO_STATUS_CODE[options[:status]].to_s
+      @status         = self.class.status_code_for(options[:status])
       @meta           = options[:meta]
     end
 

lib/jsonapi/resource.rb

@@ -541,7 +541,7 @@ def attribute(attribute_name, options = {})
         check_reserved_attribute_name(attr)
 
         if (attr == :id) && (options[:format].nil?)
-          ActiveSupport::Deprecation.warn('Id without format is no longer supported. Please remove ids from attributes, or specify a format.')
+          JSONAPI.warn_deprecated('Id without format is no longer supported. Please remove ids from attributes, or specify a format.')
         end
 
         check_duplicate_attribute_name(attr) if options[:format].nil?
@@ -581,11 +581,11 @@ def has_one(*attrs)
       end
 
       def belongs_to(*attrs)
-        ActiveSupport::Deprecation.warn "In #{name} you exposed a `has_one` relationship "\
-                                        " using the `belongs_to` class method. We think `has_one`" \
-                                        " is more appropriate. If you know what you're doing," \
-                                        " and don't want to see this warning again, override the" \
-                                        " `belongs_to` class method on your resource."
+        JSONAPI.warn_deprecated "In #{name} you exposed a `has_one` relationship "\
+                                " using the `belongs_to` class method. We think `has_one`" \
+                                " is more appropriate. If you know what you're doing," \
+                                " and don't want to see this warning again, override the" \
+                                " `belongs_to` class method on your resource."
         _add_relationship(Relationship::ToOne, *attrs)
       end