Add comprehensive improvements based on feedback

- Add CHANGELOG entry explaining version requirement fixes and backward compatibility
- Add defensive programming with shakapacker_gem_available? check
- Improve error handling for LoadError when Shakapacker gem is missing
- Add comprehensive version requirements matrix in configuration documentation
- Include feature compatibility table showing exactly what works with each Shakapacker version
- Enhanced configuration comments with version requirement notes

These improvements address all suggestions for migration guidance, defensive programming, and documentation clarity.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

CHANGELOG.md

@@ -26,6 +26,7 @@ Changes since the last non-beta release.
 #### Bug Fixes
 
 - **Doctor rake task**: Fixed LoadError in `rake react_on_rails:doctor` when using packaged gem. The task was trying to require excluded `rakelib/task_helpers` file. [PR 1795](https://github.com/shakacode/react_on_rails/pull/1795)
+- **Shakapacker version requirements**: Fixed inconsistent version requirements between basic pack generation (6.5.1+) and advanced auto-registration features (7.0.0+). Added backward compatibility for users on Shakapacker 6.5.1-6.9.x while providing clear upgrade guidance for advanced features. [PR 1798](https://github.com/shakacode/react_on_rails/pull/1798)
 
 ### [16.0.1-rc.0] - 2025-09-19
 

docs/guides/configuration.md

@@ -195,6 +195,19 @@ ReactOnRails.configure do |config|
   # `render_component` and `render_component_hash` view helper methods can
   # auto-load the bundle for the generated component, to avoid having to specify the
   # bundle manually for each view with the component.
+  #
+  # SHAKAPACKER VERSION REQUIREMENTS:
+  # - Basic pack generation: Shakapacker 6.5.1+
+  # - Advanced auto-registration with nested entries: Shakapacker 7.0.0+
+  # - Async loading support: Shakapacker 8.2.0+
+  #
+  # Feature Compatibility Matrix:
+  # | Shakapacker Version | Basic Pack Generation | Auto-Registration | Nested Entries | Async Loading |
+  # |-------------------|----------------------|-------------------|----------------|---------------|
+  # | 6.5.1 - 6.9.x     | ✅ Yes                | ❌ No              | ❌ No           | ❌ No          |
+  # | 7.0.0 - 8.1.x     | ✅ Yes                | ✅ Yes             | ✅ Yes          | ❌ No          |
+  # | 8.2.0+            | ✅ Yes                | ✅ Yes             | ✅ Yes          | ✅ Yes         |
+  #
   ################################################################################
   # components_subdirectory is the name of the subdirectory matched to detect and register components automatically
   # The default is nil. You can enable the feature by updating it in the next line.
@@ -205,6 +218,8 @@ ReactOnRails.configure do |config|
   # Default is false.
   # The default can be overridden as an option in calls to view helpers
   # `render_component` and `render_component_hash`. You may set to true to change the default to auto loading.
+  # NOTE: Requires Shakapacker 6.5.1+ for basic functionality, 7.0.0+ for full auto-registration features.
+  # See version requirements matrix above for complete feature compatibility.
   config.auto_load_bundle = false
 
   # Default is false

lib/react_on_rails/packer_utils.rb

@@ -5,6 +5,8 @@ module PackerUtils
     def self.packer
       require "shakapacker"
       ::Shakapacker
+    rescue LoadError => e
+      raise ReactOnRails::Error, "Shakapacker gem is required but not available. Please add 'shakapacker' to your Gemfile. Error: #{e.message}"
     end
 
     def self.dev_server_running?
@@ -39,12 +41,25 @@ def self.supports_async_loading?
     end
 
     def self.supports_basic_pack_generation?
+      return false unless shakapacker_gem_available?
+
       shakapacker_version_requirement_met?(ReactOnRails::PacksGenerator::MINIMUM_SHAKAPACKER_VERSION)
     end
 
     def self.supports_auto_registration?
+      return false unless shakapacker_gem_available?
+
       min_version = ReactOnRails::PacksGenerator::MINIMUM_SHAKAPACKER_VERSION_FOR_AUTO_REGISTRATION
       packer.config.respond_to?(:nested_entries?) && shakapacker_version_requirement_met?(min_version)
+    rescue StandardError
+      false
+    end
+
+    def self.shakapacker_gem_available?
+      require "shakapacker"
+      true
+    rescue LoadError
+      false
     end
 
     # This returns either a URL for the webpack-dev-server, non-server bundle or