- Add ErrVersionConflict error type and VersionConflictError for detailed
conflict information
- Implement version validation in InMemoryEventStore.SaveEvent that rejects
events with version <= current latest version
- Implement version validation in JetStreamEventStore.SaveEvent with version
caching for performance
- Add comprehensive tests for version conflict detection including concurrent
writes to same actor
- Document versioning semantics in EventStore interface and CLAUDE.md
This ensures events have monotonically increasing versions per actor and
provides clear error messages for version conflicts, enabling optimistic
concurrency control patterns.
Closes#6
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Test SaveEvent persists events correctly (single, multiple, multi-actor)
- Test GetEvents retrieves events in insertion order
- Test GetEvents with fromVersion filtering
- Test GetLatestVersion returns correct version
- Test behavior with non-existent actor IDs (returns empty/zero)
- Test concurrent access safety with race detector
- Add mutex protection to InMemoryEventStore for thread safety
Closes#3
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>