deprecate instead of replace

Author: Judahmeek

CHANGELOG.md

@@ -29,7 +29,7 @@ Changes since the last non-beta release.
 
 ### Removed (Breaking Changes)
 
-- Removed `defer_generated_component_packs` configuration option. You can use `generated_component_packs_loading_strategy` instead. [PR 1712](https://github.com/shakacode/react_on_rails/pull/1712) by [AbanoubGhadban](https://github.com/AbanoubGhadban).
+- Deprecated `defer_generated_component_packs` configuration option. You should use `generated_component_packs_loading_strategy` instead. [PR 1712](https://github.com/shakacode/react_on_rails/pull/1712) by [AbanoubGhadban](https://github.com/AbanoubGhadban).
 
 ### [15.0.0-alpha.2] - 2025-03-07
 

docs/release-notes/15.0.0.md

@@ -34,7 +34,7 @@ Major improvements to component and store hydration:
 
 ### Component Hydration Changes
 
-- The `defer_generated_component_packs` configuration has been removed. Use `generated_component_packs_loading_strategy` instead.
+- The `defer_generated_component_packs` configuration has been deprecated. Use `generated_component_packs_loading_strategy` instead.
 - The `generated_component_packs_loading_strategy` defaults to `:async` for Shakapacker ≥ 8.2.0 and `:sync` for Shakapacker < 8.2.0.
 - The `force_load` configuration now defaults to `true`.
 - The new default values of `generated_component_packs_loading_strategy: :async` and `force_load: true` work together to optimize component hydration. Components now hydrate as soon as their code and server-rendered HTML are available, without waiting for the full page to load. This parallel processing significantly improves time-to-interactive by eliminating the traditional waterfall of waiting for page load before beginning hydration (It's critical for streamed HTML).

lib/react_on_rails/configuration.rb

@@ -43,6 +43,7 @@ def self.configuration
       i18n_output_format: nil,
       components_subdirectory: nil,
       make_generated_server_bundle_the_entrypoint: false,
+      defer_generated_component_packs: false,
       # forces the loading of React components
       force_load: true,
       # Maximum time in milliseconds to wait for client-side component registration after page load.
@@ -60,7 +61,7 @@ class Configuration
                   :generated_assets_dirs, :generated_assets_dir, :components_subdirectory,
                   :webpack_generated_files, :rendering_extension, :build_test_command,
                   :build_production_command, :i18n_dir, :i18n_yml_dir, :i18n_output_format,
-                  :i18n_yml_safe_load_options,
+                  :i18n_yml_safe_load_options, :defer_generated_component_packs,
                   :server_render_method, :random_dom_id, :auto_load_bundle,
                   :same_bundle_for_client_and_server, :rendering_props_extension,
                   :make_generated_server_bundle_the_entrypoint,
@@ -70,7 +71,7 @@ class Configuration
     # rubocop:disable Metrics/AbcSize
     def initialize(node_modules_location: nil, server_bundle_js_file: nil, prerender: nil,
                    replay_console: nil, make_generated_server_bundle_the_entrypoint: nil,
-                   trace: nil, development_mode: nil,
+                   trace: nil, development_mode: nil, defer_generated_component_packs: nil,
                    logging_on_server: nil, server_renderer_pool_size: nil,
                    server_renderer_timeout: nil, raise_on_prerender_error: true,
                    skip_display_none: nil, generated_assets_dirs: nil,
@@ -122,6 +123,7 @@ def initialize(node_modules_location: nil, server_bundle_js_file: nil, prerender
       self.components_subdirectory = components_subdirectory
       self.auto_load_bundle = auto_load_bundle
       self.make_generated_server_bundle_the_entrypoint = make_generated_server_bundle_the_entrypoint
+      self.defer_generated_component_packs = defer_generated_component_packs
       self.force_load = force_load
       self.generated_component_packs_loading_strategy = generated_component_packs_loading_strategy
     end
@@ -152,9 +154,16 @@ def check_component_registry_timeout
       raise ReactOnRails::Error, "component_registry_timeout must be a positive integer"
     end
 
+    # rubocop:disable Metrics/CyclomaticComplexity
     def validate_generated_component_packs_loading_strategy
+      # rubocop:enable Metrics/CyclomaticComplexity
       if PackerUtils.shakapacker_version_requirement_met?([8, 2, 0])
         self.generated_component_packs_loading_strategy ||= :async
+      elsif defer_generated_component_packs
+        generated_component_packs_loading_strategy ||= :defer
+        Rails.logger.warn "[DEPRECATION] ReactOnRails: Use config." \
+                          "generated_component_packs_loading_strategy = :defer rather than " \
+                          "defer_generated_component_packs"
       elsif generated_component_packs_loading_strategy.nil?
         msg = <<~MSG
           **WARNING** ReactOnRails: Your current version of #{ReactOnRails::PackerUtils.packer_type.upcase_first} \