# Link-Not-Merge Determinism Test Plan

**Task:** MERGE-LNM-21-003 — replace legacy merge determinism suites with observation/linkset regressions now that `NoMergeEnabled` is defaulted to `true`.

## Objectives
- Validate raw advisory documents remain byte-stable through observation/linkset materialisation.
- Ensure conflicts detected during linkset building surface in telemetry and persisted artifacts without merge-side mutation.
- Keep canonical hash output stable for exports/evidence bundles after repeated runs.

## Test Coverage Outline
1. **Raw → Observation determinism**
   - Feed canonical advisory raw fixtures containing mixed casing, duplicate aliases, and provenance metadata.
   - Assert repeated runs of `AdvisoryObservationFactory` emit identical observations (structural equality + canonical JSON hash).
   - Verify raw linkset payload retains original ordering/whitespace while canonical linkset stays normalised.
   - Initial coverage implemented via `AdvisoryObservationFactoryTests.Create_IsDeterministicAcrossRuns` (core tests).

2. **Linkset conflict surfacing**
   - Build linksets from conflicting advisory observations (e.g., differing severity or status flags).
   - Confirm conflict markers propagate to `AdvisoryLinkset` outputs and associated metrics/log records.
   - Capture deterministic ordering of conflict explanations for evidence exports.

3. **Evidence/export parity**
   - Re-run observation/linkset pipelines against identical fixtures and assert resulting evidence manifests hash-identically.
   - Track monotonic `supersedes` chains and ensure canonical link records include `PRIMARY` schemes.

## Migration Steps
- [ ] Retire `StellaOps.Concelier.Merge.Tests` determinism suites once observation/linkset equivalents land.
- [ ] Introduce new regression fixtures under `StellaOps.Concelier.Core.Tests` (shared via `StellaOps.Concelier.Testing`).
- [ ] Wire test helpers to Mongo in-memory harness for end-to-end parity runs.
- [ ] Update documentation (`docs/migration/no-merge.md`) with validation checklist once new tests are green.

_Pending_: execute suites on a workstation with the .NET 10 preview SDK; local environment lacks a functioning CLI, so validation runs must happen downstream.