[jeremydmiller]

Three problems found next to #1106 in how projections describe themselves. All three were real: 16 of the new tests failed on the unfixed code, and the other new tests pin behaviour that was already right.

Stacked on #1106, which is still open, so this targets feat/1102-descriptor-published-types. Retarget this PR to main before merging #1106. Deleting that branch would close this PR.

1. A scoped projection reported values from an instance registration never touched

ProjectionSourceWrapperBase.Describe resolved a new instance and described that. Marten and Fisher set Lifecycle and run configure on the wrapper, and the wrapper is what runs, so the description was of something else:

Set at registration	Reported before
Lifecycle = Inline	Async, with daemon metrics and spans that never exist
Name = "RenamedAtRegistration"	MyAggregate, and a shard name that doesn't run
Version = 3	1
IncludeType<BEvent>()	missing from AppliedEvents

EventStoreUsage.PopulateAgentUris reads Lifecycle and ShardNames, so an Inline projection also got an agent URI for an agent that doesn't exist, and a renamed one got a URI under the wrong name.

The wrapper still calls source.Describe(store), then overlays what registration decided through one internal SubscriptionDescriptor.ReadRegistrationFrom. This replaces the PublishedTypes line #1106 added. Rebuilding from the wrapper was the alternative, but Describe is virtual on an event projection and that would lose anything a projection adds to its own description. There is a test for that.

This affects Marten and Fisher. Polecat has no scoped wrappers.

2. CompositeProjection.PublishedTypes() dropped the composite's own declarations

The override replaced the base and returned only the members' types, although the SubscriptionDescriptor.PublishedTypes docs already promised these. The base now does what FisherCompositeProjection did, with two differences:

• It concatenates base.PublishedTypes(), so a type given to RegisterPublishedType on a composite counts too.
• The composite's own types go after the members', because Polecat and Fisher read PublishedTypes().FirstOrDefault() as a projection's state type.

Store sources read at origin heads: marten 2f2769bca, polecat 8545249, fisher 3f4c4be. Only Fisher overrides this, and it stays correct, just redundant. Wolverine has no subclass.

This is more than a descriptor change, because PublishedTypes() has other readers. For a composite that names a type for itself, which should be rare:

• Marten: AllPublishedTypes now materialises a mapping for that type, and ProjectionScenario wipes it. Its rebuild teardown reads CleanUps and doesn't change.
• Polecat: ConfiguredDocumentProviders now creates a provider for it. CollectTeardownTargets adds PublishedTypes() before it checks TeardownDataOnRebuild, so a composite with its own rule and TeardownDataOnRebuild = false now wipes that table. Polecat already treats ordinary projections this way, but this is the one change that could surprise someone.
• JasperFx: AsyncShardsPublishingType and RebuildProjectionAsync(Type) can now resolve that type to the composite, and TryFindAggregate stays null-safe.

3. Teardown needed the guard, and the path is worse than the failed-validation case

Registering void before validation fails is harmless by itself, because the projection never gets registered. But a generated dispatcher skips method validation entirely, and the analyzer silently drops a Create or Transform that returns void, Task or ValueTask. A partial projection with one good method and one bad one therefore passes validation with:

Options.CleanUps: [DocOne, System.Void, Task, ValueTask]

The same list went into StorageTypes and PublishedTypes(), so each store was handed System.Void as a document type.

The guard now sits in EventProjectionApplication.PublishedTypes(), where the list starts, so it covers all of those readers. The filter #1106 added to the descriptor became dead code and is removed.

Not bugs

• ScopedProjectionWrapper describes itself, so it always reported what was registered. It is pinned by a test. Its // TODO -- some way to understand the lifecycle is out of date.
• AppliedEvents on a scoped aggregation matches the unwrapped projection unless registration changes the filter.
• Task<T> and ValueTask<T> from Create already registered the document type, and now have a test.

Gate

./build.sh Test --root "$PWD" passed on this commit, on net9.0 and net10.0, with no failures. Every target succeeded:

Project	Passed	Skipped
EventTests	1,717	0
EventStoreTests	350	23
InMemoryEventStoreTests	139	9
CoreTests	810	1
CodegenTests	495	0
CommandLineTests	312	0

Counts are per framework. The source generator, Aspire and MEAI suites and the smoke targets passed too.

CI has not run on this PR. dotnet.yml only triggers for PRs targeting main, so the empty check list is not a pass. It will run once this is retargeted, and it should be green before merging.

Not run against a real store. The store effects above come from reading their sources. The compliance suite has no store-neutral way to reach a composite's Options or a scoped registration, so these are unit tests only, and I left the suite alone rather than add a builder member each store would have to implement.

Follow-ups, not done here

• A void or Task Create under a generated dispatcher never runs, and nothing says so. This PR stops the bad teardown target, but the method is still dropped silently while its event stays in IncludedEventTypes. Without the generator the same projection is refused at startup. It needs an analyzer diagnostic or validation that also covers generated dispatchers. This comes from reading the analyzer and emitter.
• Remove FisherCompositeProjection.PublishedTypes() once Fisher pins a release with this.
• ScopedProjectionWrapper resets Version to 1 (or its [ProjectionVersion]) after copying the source's, so a version set in a projection's constructor is lost. ProjectionSourceWrapperBase keeps it. This one is not a descriptor error, because the shard runs under the same number, but the two wrappers disagree. Also from reading only.

🤖 Generated with Claude Code