This commit addresses issue #60 by documenting and enforcing the immutability
guarantees of the event store:
- Document that EventStore interface is append-only by design (no Update/Delete methods)
- Document the immutable nature of events once persisted as an audit trail
- Add JetStream stream retention policy configuration documentation
- Add comprehensive immutability test (TestEventImmutability_InMemory, TestEventImmutability_Sequential)
- Enhance InMemoryEventStore to deep-copy events, preventing accidental mutations
- Update README with detailed immutability guarantees and audit trail benefits
The EventStore interface intentionally provides no methods to modify or delete
events. Once persisted, events are immutable facts that serve as a tamper-proof
audit trail. This design ensures compliance, debugging, and historical analysis.
Acceptance criteria met:
- EventStore interface documented as append-only (event.go)
- JetStream retention policy configuration documented (store/jetstream.go)
- Test verifying events cannot be modified after persistence (store/immutability_test.go)
- README documents immutability guarantees (README.md)
Closes#60
Co-Authored-By: Claude Code <noreply@anthropic.com>
Add a README.md that gives developers a quick understanding of what
Aether is and how to get started. Includes:
- Project description and why Aether exists
- Installation instructions
- Quick start code example showing event creation, persistence, and replay
- Key concepts (immutability, derived state, version consistency)
- Links to further documentation
- CI badge
Closes#44
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
