pacta-conformance

A backend-agnostic conformance suite for Pacta Registry implementations.

Any Registry backend — in-memory, SQLite, Postgres, or your own — must pass the same lease-lifecycle contract: claim, settlement, lapse, heartbeat (including the now == expiry boundary), deferred reclaim on release, and the at-least-once safety property that a reclaimed pact rejects the prior holder's authority. The suite is generic over Registry and takes a seeding closure, so a backend runs it from its own test module; time is driven through the trait by passing controlled Timestamp values, never a wall clock.

Beyond the sequential lifecycle scenarios it verifies atomic authority under real concurrency through the public trait only (never by inspecting a backend's locking):

• run_contention — for a sync Registry: two workers race a settlement on one claimed pact (exactly one succeeds) and two workers race a claim on one available pact (exactly one gets it).
• run_async_contention — the same at-most-once claim and settlement checks for a ready-future AsyncRegistry, driven by OS threads with no async runtime.

For the async binding the suite runs the one shared scenario set two ways, so coverage cannot drift and a real backend never re-declares scenarios:

• run_async_with(make, driver) — the runtime-compatible entry: a real-reactor backend drives the scenarios on its own runtime via a small BlockingDriver (for example one wrapping tokio::runtime::Runtime::block_on). It imposes no Send bound on the backend's futures and pulls no async runtime into this crate.
• run_async — a convenience for ready-future backends, using the built-in SelfProgress driver. It is not correct for a backend whose futures park pending real I/O or a timer; such a backend uses run_async_with.

The suite proves behavioral equivalence to the shared lifecycle (eligibility, transitions, lapse/reclaim, at-most-once contention). It does not prove a backend's query shape — that claim selection is full-scan-free is a separate obligation established by review, since a sequential functional suite cannot observe query cost.

Use it as a dev-dependency to prove a backend correct.

Part of Pacta.

License

Licensed under either of Apache-2.0 or MIT, at your option.