compatibility

Wright Compatibility Regression Evidence

This directory contains Wright consumer regression evidence for the source and integration paths that still exist in this repository. It does not own the live upstream compatibility oracles for OPY or DEL/OSTW.

Repository ownership is defined by ADR-0009:

• wrightkit/opy-rs owns OPY language semantics and the pinned OverPy oracle/corpus used to establish OPY compatibility evidence;
• wrightkit/del-rs owns DEL/OSTW language semantics and is the target owner for the pinned OSTW reference evidence;
• wrightkit/workshop-rs owns canonical Workshop semantics and WIR;
• Wright owns tooling, orchestration, provider integration, and regression coverage for the language paths it currently consumes.

What remains in Wright

fixtures/ contains immutable source inputs plus recorded reference snapshots used by current Wright migration/product regression tests. The historical filename oracle.json is retained as a data-format compatibility choice; its presence does not mean Wright owns or executes the upstream oracle.

Each fixture has the form:

compatibility/fixtures/<category>/<name>/
  fixture.json   # fixture identity, expected status, and provenance
  source.opy     # input, or the source path named by fixture.json
  oracle.json    # immutable recorded reference result consumed by Wright tests

Wright validates these records without installing an upstream compiler:

python3 -m unittest discover -s compatibility/tests

compatibility/tests/test_evidence.py checks fixture identity, source hashes, expected status, snapshot structure, output hashes, and imported-source provenance. It deliberately has no Node, .NET, OverPy, or OSTW runtime dependency.

Current Wright-native differential and release-gate tests may consume selected recorded snapshots while wright-opy / wright-ostw remain migration paths. Those tests protect Wright's current integration behavior; they are not the authoritative language compatibility suite.

Updating OPY reference evidence

Do not regenerate OPY reference results in Wright. The live OverPy pin, acquisition environment, oracle runner, corpus evolution, differential expectations, and support matrix are owned by wrightkit/opy-rs.

When Wright needs updated OPY evidence:

1. establish and review the reference change in opy-rs;
2. import only the immutable evidence required by a Wright consumer regression;
3. preserve source identity, reference identity, hashes, and provenance; and
4. update the Wright regression that consumes the evidence in the same change.

Wright does not carry its own OverPy npm package, lockfile, live oracle runner, or generic owner-side differential harness.

OSTW migration state

compatibility/ostw/ is a temporary ownership exception left by the repository split. It still contains the pinned OSTW v3.4.0 reference metadata, explicit-root corpus/probes, recorded results, reconstruction evidence, and legacy oracle runner required by the existing wright-ostw migration tests.

These files must move to wrightkit/del-rs before they are removed from Wright. Until that migration is complete:

• do not treat Wright as the durable owner of OSTW semantics or reference evidence;
• do not expand the Wright-side oracle into new authoritative DEL/OSTW contracts;
• keep only changes needed to preserve existing migration/integration evidence;
• do not run the upstream OSTW reference as a default Wright merge gate.

After the del-rs owner-side migration is accepted, Wright should retain only those immutable DEL/OSTW snapshots that are concretely required by its provider or migration integration tests, then remove the remaining owner-style harness.

Fixture provenance

Every redistributed fixture must have reviewable provenance. fixture.json records at least:

• unique fixture id and source path;
• expected compile status;
• origin and license;
• whether redistribution is permitted; and
• for imported sources, an immutable source commit and modification status.

Third-party code, generated output, or user data must not be added without a redistribution/provenance review. When source cannot be redistributed, record a hash or acquisition procedure in the owning repository instead of committing it here.

CI boundary

Default Wright CI may validate:

• committed evidence integrity;
• Wright-native migration/product differentials against recorded evidence;
• LPP/provider integration;
• compiler/tooling behavior and distribution contracts.

Default Wright CI must not require live OverPy or OSTW runtimes merely to prove that an unrelated Wright change is mergeable. Live upstream oracle reproduction belongs to the corresponding language repository's evidence workflow.

See docs/compatibility.md for Wright's compatibility claim model and priority rules.