---
id: suite-column-mem
name: Conformance suite — factory binding and the mem column (the reference column)
status: pending
depends_on: [store-read-paths, store-put-paths, gc-protocol]
scope: moderate
risk: medium
impact: phase
level: implementation
tags: [wave-2, suite, mem]
---

## Description

Bind the conformance harness to the real facade and grow the **mem
column** — the contract-reference column that defines the required set
every other engine's rows mirror (store-api.md invariant 7; ADR-011 §2).

- **The factory binding** (the skeleton's anticipated wave-2 moment):
  bind `StoreFactory::Store` to the real facade type — most plausibly
  the associated type collapsing to the concrete `Store` across all
  factories. If binding reveals a shape correction, make it and record
  it in `tests/conformance/factory.rs` + `README.md` per the
  skeleton's note. The mem factory vends fresh, isolated in-memory
  stores (no shared state between rows) with idempotent teardown; mem
  never skips (README §SKIP posture — SKIP machinery stays unneeded
  until the SQL waves).
- **The mem column's rows**, each ADR-stamped per the convention
  (`Contract stamp:` citing the pinning spec §/ADR §), tracing to the
  backlog entries:
  - **INV-1 round-trips**: whole-blob put/get byte-identical under the
    canonical derivation, over a content matrix looping both put paths
    (known-length, unknown-length) in-body; the git-interop test
    remains the derivation's source of truth.
  - **INV-2 dedup**: identical content twice (same and different put
    path) is one pool entry; the re-put's `Pin` protects exactly as a
    fresh put's.
  - **INV-3 stage hygiene**: exact counts over both put paths and both
    failure modes (explicit discard, failed commit) — zero residue on
    failure, exactly one committed entry on success (the degenerate
    kv stage form).
  - **INV-4 sweep safety**: single-node exact-count family — happy
    shape (exact `SweepReport` counts), abort shapes
    (`ProtectFailed`, `NoLivenessSources` — nothing deleted,
    `Ok(SweepReport)` always), and the sweep-vs-pinned-put race.
  - **INV-5 list correctness**: asserted through sweep outcomes (exact
    counts), never by comparing enumerated lists directly.
  - **INV-6 stat discipline**: `stat` returns length + algorithm
    without fetching content.
  - **Constructor-mode rows** (facade contract, ADR-011 §4 / ADR-012
    §6.2/§6.3): mem-only mode; kv-only(mem) over-threshold put-time
    rejection (known-length immediate, unknown-length mid-stream).
- Rows take factories, never stores (factory.rs contract); a failing
  assertion panics the row; teardown is idempotent against that path.

## Acceptance Criteria

- [ ] `StoreFactory::Store` bound to the real facade; any shape
      correction recorded in factory.rs + README
- [ ] The mem column green: INV-1/2/3/4/5/6 rows plus constructor-mode
      rows, every row ADR-stamped and traceable to the backlog
- [ ] The mem column's row set is the reference set (INV-7's basis) —
      recorded in README as what other columns mirror
- [ ] Factory isolation + idempotent teardown hold (fresh store per
      call; teardown safe against a panicking row)
- [ ] `cargo test --features mem` green (the column runs under its
      feature); clippy/fmt gates green

## References

- tests/conformance/README.md (the conventions this grows against)
- tests/conformance/backlog.rs (INV-1…7 entries and their first-column plan)
- docs/architecture/store-api.md (§Invariants — the test gate)
- docs/architecture/decisions/011-vocabulary-tiers-engines-and-fleet-state.md §2 (mem's reference role)
- docs/plans/implementation.md (Decided points — suite home; §Wave 2 — suite columns)

## Notes

> To be filled by implementation agent

## Summary

> To be filled on completion