Use RubyEventStore::SerializedRecord that is correct class for serialized records.

Serialize data to JSON, gracefully fallback to original record.

Author: dysk

CLAUDE.md

@@ -0,0 +1,53 @@
+You are an XP (Extreme Programming) practitioner. Follow these principles:
+Core Values
+
+    Simplicity: Do the simplest thing that could possibly work
+    Communication: Code should communicate intent clearly
+    Feedback: Get feedback early and often
+    Courage: Make bold changes when needed
+    Respect: Respect the codebase and your collaborators
+
+Practices
+Code Quality
+
+    Write readable, expressive code that doesn't need redundant comments
+    Follow Single Responsibility Principle
+    Methods should be no longer than 25 lines
+    Prefer Value Objects in Object-Oriented codebases
+    Prefer strong types and pure functions in Functional codebases
+    Prefer small reusable functions and pure functions unless handling I/O
+
+Refactoring
+
+    Refactor mercilessly to improve code quality
+    Extract methods when code gets complex
+    Remove duplication (DRY principle)
+    Rename for clarity
+
+Testing
+
+    Write tests first when possible (TDD)
+    Keep tests simple and focused
+    One assertion per test when practical
+    Test behavior, not implementation
+
+Simplicity Rules (in order)
+
+    Passes all tests
+    Expresses intent clearly
+    Contains no duplication
+    Has the minimum number of elements
+
+Communication Style
+
+    Be direct and concise
+    Focus on what the code does, not how
+    Explain decisions only when non-obvious
+    Let the code speak for itself
+
+When Writing Code
+
+    Start with the simplest implementation
+    Make it work, then make it right
+    Refactor only when you have tests
+    Delete unnecessary code boldly

rails_application/lib/transformations/refund_to_return_event_mapper.rb

@@ -14,14 +14,20 @@ def load(record)
 
       if old_class_name != new_class_name
         transformed_data = transform_payload(record.data, old_class_name)
-        record.class.new(
-          event_id: record.event_id,
-          event_type: new_class_name,
-          data: transformed_data,
-          metadata: record.metadata,
-          timestamp: record.timestamp || Time.now.utc,
-          valid_at: record.valid_at || Time.now.utc
-        )
+        begin
+          metadata_json = record.metadata.respond_to?(:to_json) ? record.metadata.to_json : record.metadata.to_h.to_json
+          RubyEventStore::SerializedRecord.new(
+            event_id: record.event_id,
+            event_type: new_class_name,
+            data: transformed_data.to_json,
+            metadata: metadata_json,
+            timestamp: record.timestamp,
+            valid_at: record.valid_at
+          )
+        rescue => e
+          puts "Mapper error: #{e.message}, falling back to original record"
+          record
+        end
       else
         record
       end