conformance-snapshots

README

conformance-snapshots

Go reproduction of the pinned Rust snapshots/handles/termination oracle registry (rust-oracle/src/bin/conformance-snapshots.rs, crate v8 =152.2.0, engine 15.2.124.1-rusty, target x86_64-pc-windows-msvc).

What is pinned

The 15-check normalized JSON-lines report (rust-oracle/tests/fixtures/conformance-snapshots-v8_152.2.0_x86_64-pc-windows-msvc.jsonl) is reproduced byte-for-byte by TestSnapshotFixture:

• snapshot creation and startup data (snapshot/create_blob_policies, snapshot/startup_data_predicates)
• snapshot consumption: default-context round trip through CreateParams::snapshot_blob, snapshot-of-snapshot chains, added contexts with Context::from_snapshot, exactly-once isolate/context data retrieval with NoData/BadType outcomes (snapshot/default_context_create_params_roundtrip, snapshot/chained_roundtrip, snapshot/add_context_from_snapshot, snapshot/isolate_data_once, snapshot/context_data_once_and_badtype)
• Global identity, clone, raw round trip, cross-isolate equality, and drop-after-dispose (handle/global_*)
• weak finalizers under forced GC, guaranteed finalizers, drop-cancel and equality/clone semantics (handle/weak_*)
• same-thread terminate/request/cancel delivery semantics (terminate/request_and_cancel_during_js)

Subprocess modes

The Rust oracle characterizes four scenarios in dedicated subprocesses (rust-oracle/tests/snapshots_handles_negative.rs); the Go coverage of those scenarios lives in the module-root tests (terminate_test.go, snapshot_test.go) because Go's test binary already provides the subprocess isolation:

Rust mode	Go coverage	Outcome
mode=terminate-loop	TestSubprocessTerminateLoopFromOtherThread	matches: one deterministic JSON line
mode=invalid-startup-data-fatal	TestSubprocessInvalidStartupBlobGuard	deviation: Go guards and survives (the pinned crate aborts in a V8 CHECK)
mode=global-eq-after-dispose	TestGlobalDropAfterIsolateDispose	deviation: Go returns errors instead of panicking
mode=drop-creator-without-blob	TestSnapshotCreatorLifecycle	deviation: Go resolves the drop panic into an explicit, safe SnapshotCreator.Close

Run

go test ./conformance-snapshots -v

This runner performs no platform shutdown, exactly like the oracle's snapshots runner.