github-issue-929-add-serialized-command-executor-contract-for-wasm-local-re

[tomohisa]

Summary

Goal

Introduce a serialized command executor contract in Sekiban so WASM local/remote command models can use the same server-side commit semantics without relying on typed ISekibanExecutor paths.

Why this is needed

Current Sekiban command execution is typed-first (ISekibanExecutor, ICommandContext).
For WASM command execution, we need a boundary where:

• tag state is fetched as SerializableTagState,
• command output events are accepted as serialized payload candidates,
• server generates event metadata and applies consistency reservation before write.

Without this, SekibanWasmRuntime must duplicate commit semantics outside Sekiban.

Scope (Sekiban side only)

• Add serialized command executor interface + DTOs in Core.
• Add Orleans implementation with reservation/write/confirm/cancel flow.
• Register via DI (additive).
• Add tests and docs.

References

• tasks/0220_serialized_command_wasm_contract/design.md
• tasks/0220_serialized_command_wasm_contract/implementation-plan.md
• dcb/src/Sekiban.Dcb.Core/Storage/IEventStore.cs
• dcb/src/Sekiban.Dcb.Core/Actors/CoreGeneralSekibanExecutor.cs

Task Checklist

Phase 1: Contract

• Add ISerializedSekibanDcbExecutor
• Add SerializedCommitRequest, SerializableEventCandidate, SerializedCommitResult

Phase 2: Orleans implementation

• Implement GetTagStateAsync (serialized return)
• Implement CommitSerializableEventsAsync with consistency reservation flow

Phase 3: Wiring

• Register implementation in Orleans DI extensions
• Keep existing typed executor registrations untouched

Phase 4: Tests

• success path (single event)
• success path (multi event)
• conflict path (mismatch)
• rollback/cancel path

Phase 5: Docs

• Add concise docs for purpose and intended WASM integration usage

Success Criteria

• Serialized command executor works end-to-end in Orleans runtime.
• Existing ISekibanExecutor behavior remains unchanged.
• Contract is enough for SekibanWasmRuntime to implement both local and remote WASM command paths without additional Sekiban API changes.

Non-goals

• Implement full WASM runtime in Sekiban.
• Replace typed command APIs.

Execution Report

Piece default completed successfully.

Closes #929

[tomohisa]

Follow-up fixes pushed for review findings:

• Hardened cancellation/reservation flow:
  • removed from serialized reservation path
  • reservation now uses direct await with cancellation checks
  • added guarded rollback () when failure/cancellation happens before confirmation
• Added request validation for consistency tags:
  • reject duplicate
  • reject consistency tags not present in

• Added tests:

Validation:

• MSBUILD : error MSB1009: Project file does not exist.
  Switch: dcb/tests/Sekiban.Dcb.WithResult.Tests/Sekiban.Dcb.WithResult.Tests.csproj passed on net9/net10.

[tomohisa]

Follow-up fixes pushed for review findings:

• Hardened CommitSerializableEventsAsync cancellation/reservation flow:
  • removed ContinueWith(..., cancellationToken) from serialized reservation path
  • reservation now uses direct await with cancellation checks
  • added guarded rollback (CancelReservationsAsync) when failure/cancellation happens before confirmation
• Added request validation for consistency tags:
  • reject duplicate ConsistencyTags
  • reject consistency tags not present in EventCandidates[*].Tags
• Added tests:
  • CommitWithUnknownConsistencyTag_Should_Fail
  • CommitWithDuplicateConsistencyTags_Should_Fail

Validation:

• dotnet test dcb/tests/Sekiban.Dcb.WithResult.Tests/Sekiban.Dcb.WithResult.Tests.csproj --filter "FullyQualifiedName~SerializedCommitTests|FullyQualifiedName~TagReservationHelperTests" passed on net9/net10.

[sonarqubecloud]

Quality Gate failed

Failed conditions
8.4% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud