Stratara.Mediator 3.3.0

• net10.0

  • JetBrains.Annotations (>= 2025.2.4)
  • Microsoft.Extensions.DependencyInjection.Abstractions (>= 10.0.8)
  • Microsoft.Extensions.Hosting.Abstractions (>= 10.0.8)
  • Microsoft.Extensions.Logging.Abstractions (>= 10.0.8)
  • Microsoft.Extensions.Options (>= 10.0.8)
  • OpenTelemetry.Api (>= 1.15.3)
  • Stratara.Abstractions (>= 3.3.0)
  • Stratara.Diagnostics (>= 3.3.0)

Two capabilities the framework advertised but did not provide, and a set of guards for behaviour
that failed by succeeding. Crypto-shredding was the headline feature with no way to perform an
erasure; a web host had one mapper for the four failure types it has to answer for. Alongside those,
three things that reported success while doing nothing now report the truth instead — which is why
this release carries breaking entries despite adding no signature you have to change.

### Added

- **`ISubjectEraser` — an erasure is now one call.** Crypto-shredding was the framework's headline
 capability with no way to perform an erasure: four separate sweeps existed, nothing composed them,
 and a consumer had to know all four and get the order right themselves. `AddStrataraErasure()`
 registers a composed operation that sweeps API keys, scoped settings, directory memberships and
 key material — in that order, because a credential that still works can act mid-erasure and
 shredding the key first makes every other plane unreadable. It reports what each plane covered,
 and stops at the first failing plane rather than continuing, so a failed settings sweep is never
 followed by the key shred. What it deliberately does **not** cover is documented: read models your
 own projections built, unprotected event-stream data, the command audit log and outbox, and
 system-wide key material.
- **`AddStrataraProblemDetails()` — one error shape for every framework rejection.** The framework
 raises three failure types a web host has to answer for and shipped a mapper for one of them, so
 both consumers wrote the missing half themselves. The new handler maps a validation rejection to
 `400` with the failures grouped by the field each concerns, and an authorization refusal or
 tenant-access denial to `403`, all as RFC 7807 problem responses. It is opt-in and converts nothing
 else: any failure the framework did not raise propagates untouched, so a host keeping its own error
 model simply does not register it.
- **`ITransaction.SaveChangesIdempotentAsync` — the idempotent-projection write the framework was
 writing by hand.** A projection sees the same event twice under at-least-once delivery, and a row
 can vanish between the read and the write; neither is a fault. The helper commits, and on a
 concurrency conflict asks whether the write's target still exists: gone means a concurrent bundle
 reached the same end state and the commit is satisfied, still there means a real conflict and the
 exception is rethrown so the bundle fails as it must. `TenantProjection` now uses it — and gains
 the distinction, having previously swallowed every conflict.
- **Three guides that did not exist**: evolving an event schema, using the resilience policies, and
 writing an update handler. Each leads with the constraint that costs most to discover late — an
 upcaster sees ciphertext and snapshots are never upcasted; a retry re-runs your handler; a property
 missing on either side of an update is ignored in silence.

### Changed

- **BREAKING — the development key store no longer pretends to erase.** `DummyKeyStore.RevokeAsync`
 and `EraseScopeAsync` completed successfully and shredded nothing, so a consumer exercising an
 erasure path in development got a green result and no shredding. Both now throw
 `NotSupportedException`. The store derives a single key from a fixed pass-phrase and holds no key
 material it could destroy; reporting success was the defect. Register a real `IKeyStore` — the
 file-backed envelope store, an HSM, Key Vault, KMS — to exercise crypto-shredding.
- **BREAKING — a host refuses to start when an aggregate cannot be restored from its snapshot.** An
 aggregate property that holds state and cannot be set from outside the type is not restored by a
 snapshot: the aggregate rebuilds, the events after the snapshot apply, and only what the snapshot
 held for that property is gone — silently, and worse the better snapshotting works.
 `AddEventSourcing()` now scans the registered aggregates at start-up and fails, naming the
 aggregate and the property. Give it a public setter; aggregates use `public set` rather than
 `private set` precisely because snapshot deserialization needs it. Computed properties are
 unaffected — they hold no state and are recomputed after a restore.
- **BREAKING — test-support packages are now kept out of projects that are not test projects.** Both
 `Stratara.Testing` and `Stratara.Testing.EntityFrameworkCore` ship an MSBuild check that fails the
 build with `STRATARA1001` when a referencing project is neither a test project nor opted out. Set
 `StrataraAllowTestSupportOutsideTests=true` for a deliberate exception such as a sample or a
 benchmark. The check travels with the package, so it fires on a `PackageReference` and not on a
 project reference inside a single solution.
- **`AddStrataraTestingEventStore` refuses to register into a running host.** It wires an in-memory
 SQLite database and in-memory doubles, which would start successfully in production and lose every
 write. It now throws `InvalidOperationException` when a registered `IHostEnvironment`, or
 `DOTNET_ENVIRONMENT` / `ASPNETCORE_ENVIRONMENT`, names anything other than `Development`. Where no
 environment is stated at all — the ordinary unit test, which has no host — the call is allowed, so
 existing test suites are unaffected.
- **`command.duration` is documented as what it measures.** It was described as end-to-end command
 latency and is recorded only in the outbox worker, so a host dispatching in-process saw an empty
 histogram and a host doing both saw half its traffic. The instrument and its tags are unchanged —
 only the description.
- **Settings resolve in one read per scope instead of one per setting and scope.** Twenty inherited
 settings over a four-scope fallback chain were up to eighty store round trips; each scope is now
 loaded once. Same fallback order and same results.
- **Snapshot evaluation no longer opens an extra transaction per stream** on the write hot path.

### Deprecated

- **`UseAuthorizationExceptionTo403()`, removed in the next major version.** It maps two refusals to
 a bare status code with no body; `AddStrataraProblemDetails()` supersedes it with a full problem
 response that also covers validation. It keeps working for now — the compiler warning is the
 migration notice. Do not register both: the middleware answers first and the handler never sees the
 exception.