Diagnostics

Immediate.Cache ships three analyzer diagnostics, all in the ImmediateCache category, all introduced in release 2.0.

ID	Title	Severity	Configurable	Code fix
IC0001	Cache nesting is not allowed	Error	No	None
IC0002	Cache Target must be a [Handler]	Error	No	None
IC0003	Cache Target Handler must have return value	Error	No	None

All three are reported on the cache class declaration, and only fire on a class carrying [CacheFor<T>]. The package ships no code fixes.

IC0001 — Cache nesting is not allowed

Cache '{0}' must not be nested in another type

The generator only accepts top-level cache classes; a nested one is skipped. Move the cache class out of its containing type — a file-scoped namespace and a sealed partial class of its own.

// Reports IC0001
public class Outer
{
	[CacheFor<GetUsersQuery>]
	public sealed partial class GetUsersQueryCache { }
}

// Correct
[CacheFor<GetUsersQuery>]
public sealed partial class GetUsersQueryCache { }

Note that a nested class without [CacheFor<>] is fine; the rule only inspects annotated types.

IC0002 — Cache Target must be a [Handler]

Cache Target class '{0}' is not marked as [Handler]

The type argument to [CacheFor<T>] must be an Immediate.Handlers handler. Immediate.Cache explicitly wraps handlers only — it cannot cache an arbitrary service or method.

// Reports IC0002 — GetUsersQuery has no [Handler]
[CacheFor<GetUsersQuery>]
public sealed partial class GetUsersQueryCache { }

public sealed partial class GetUsersQuery { … }

Add [Handler] to the target, or point the attribute at the handler class rather than at its request or response type.

IC0003 — Cache Target Handler must have return value

Cache Target class '{0}' must return a value

The target’s handle method must return ValueTask<T>. A command handler returning bare ValueTask produces no response, so there is nothing to cache.

// Reports IC0003
[Handler]
public sealed partial class DeleteUserCommand
{
	private async ValueTask HandleAsync(Command _, CancellationToken token) { … }
}

The CA2000 suppressor

OwnedDisposableScopeSuppressor (suppression id OwnedDisposableScopeSuppression) suppresses CA2000 — Dispose objects before losing scope on the out argument of a call to Owned<T>.GetScope(out …):

await using var scope = owned.GetScope(out var service);

CA2000 fires because service may be IDisposable and is not itself disposed. That is safe here: the service was resolved as the root of the scope held by the returned OwnedScope<T>, so disposing the scope — which the await using does — disposes the service along with everything else the scope created. Disposing service directly would be wrong, not merely redundant.

The suppression is deliberately narrow. It applies only when the receiver of GetScope is an Immediate.Cache.Shared.Owned<T>; an out parameter from any other method, a returned disposable, or a new disposable is left alone.

Cache hits and the behavior pipeline

The handler does not run on a cache hit. The cache resolves IHandler<TRequest, TResponse>, so the whole Immediate.Handlers behavior pipeline sits inside the cache miss. See How it works.