# 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.
   - Coverage landed via `AdvisoryObservationFactoryTests.Create_PreservesRawReferencesForConflictAudits` (raw linkset + attribute parity) and `AdvisoryEventLogTests.AppendAsync_SortsConflictStatementIds` (canonical conflict JSON + stable hashes).

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.
   - `JsonExportSnapshotBuilderTests.WriteAsync_DifferentInputOrderProducesSameDigest` now proves export bundles remain byte-identical regardless of advisory enumeration order; digest sampling extends `ProducesIdenticalBytesAcrossRuns`.

## Mongo2Go/OpenSSL toolchain

Concelier solution tests (and most connector suites) depend on Mongo2Go’s embedded `mongod`, which is linked against OpenSSL 1.1. The repo already ships the required libraries in `tests/native/openssl-1.1/linux-x64/{libcrypto.so.1.1,libssl.so.1.1}`; use them instead of installing global packages so offline runners stay deterministic.

1. Add the shim to your shell before executing any Mongo-backed suite:

   ```bash
   export LD_LIBRARY_PATH="$(git rev-parse --show-toplevel)/tests/native/openssl-1.1/linux-x64:${LD_LIBRARY_PATH:-}"
   ```

2. For single commands you can prefix the invocation (handy for CI copy/paste):

   ```bash
   LD_LIBRARY_PATH="$(pwd)/tests/native/openssl-1.1/linux-x64" \
     dotnet test src/Concelier/StellaOps.Concelier.sln --nologo
   ```

3. The shim’s provenance and troubleshooting notes live in `tests/native/openssl-1.1/README.md`; reference it when mirroring the toolchain into air-gapped runners.

## Migration Steps
- [x] Retire `StellaOps.Concelier.Merge.Tests` determinism suites once observation/linkset equivalents land.
- [x] 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.