# testing/contracts

## Purpose

Cross-module interface contracts and shared contract test fixtures. Two responsibilities:
1. **Contract tests** — verify that model types (`StageId`, `TransitionId`, `WorkflowGraph`, `ContextSnapshot`, `ValidationReport`) and provider implementations (`InferenceProvider`, inference router, resource probes) satisfy their declared interfaces.
2. **Reusable fixtures** — `testFixtures` source set exports `ProjectionContractTest`, `ReplayContractTest`, `SessionReplayContractTest`, `CountingProjectionContractTest`, and `NoopArtifactStore` for use by other test submodules.

## Ownership

Tests and test fixtures here. Production modules exercised: `core:events`, `core:transitions`, `core:sessions`, `core:validation`, `core:approvals`, `core:artifacts`, `core:kernel`, `core:inference`, `core:context`, `infrastructure:inference:commons`.

## Local Contracts

- Contract test fixtures in `testFixtures/` are the canonical base for projection and replay contract verification — other submodules inherit from them.
- `koverVerify` is disabled for this submodule (fixture code is not independently measurable).

## Work Guidance

- Suspend tests use `runBlocking { ... }`.
- `ConcurrencyRunner` and `DeterministicBarrier` in `main/` are utilities for concurrency contracts — do not add state to them.

## Verification

```
./gradlew :testing:contracts:test --rerun-tasks
```

## Child DOX Index

No child AGENTS.md (leaf module).