test(event-subscriber): project zaak-created notifications into the read projection (refs #7)

Failing unit + acceptance tests for the Event Subscriber's NotificationProjector:
a zaken/zaak/create notification yields one INGEDIEND projection row, duplicate
deliveries collapse to one row, non-zaak/non-create notifications are ignored, and
a rebuild repopulates the projection from the durable notification log (PRD §8.4).

The projector is a no-op stub so the tests compile and fail on the assertions; the
implementation follows in the green commit. The notification log doubles as the
idempotency guard and rebuild source so a rebuild needs no OpenZaak access (§8.1).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/acceptance/Acceptance.csproj

@@ -18,6 +18,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\services\acl\Acl.Application\Acl.Application.csproj" />
     <ProjectReference Include="..\..\services\acl\Acl.Infrastructure\Acl.Infrastructure.csproj" />
+    <ProjectReference Include="..\..\services\event-subscriber\EventSubscriber.Application\EventSubscriber.Application.csproj" />
   </ItemGroup>
 
 </Project>

tests/acceptance/Features/RegisterProjectieBijwerken.feature

@@ -0,0 +1,19 @@
+# language: en
+# Drives S-06 (#7). On a zaak-created notification from NRC the Event Subscriber writes a
+# rebuildable read-projection row (PRD §8.4). This scenario exercises the use case against an
+# in-memory stand-in for the projection store and notification log; real OpenZaak → NRC →
+# subscriber delivery is verified by the live-stack check (verify-projection, ADR-0007/#58).
+Feature: Register-projectie bijwerken op een zaaknotificatie
+  Als openbaar register wil ik dat een aangemaakte zaak in de projectie verschijnt
+  zodat het register de ingediende registratie kan tonen.
+
+  Scenario: Een zaaknotificatie levert een rij met status INGEDIEND
+    Given a zaak is created in OpenZaak with id "11111111-1111-1111-1111-111111111111"
+    When the NRC notification for that zaak is delivered to the event subscriber
+    Then the register projection contains a row for "11111111-1111-1111-1111-111111111111" with status "INGEDIEND"
+
+  Scenario: Dezelfde notificatie tweemaal levert geen duplicaat
+    Given a zaak is created in OpenZaak with id "22222222-2222-2222-2222-222222222222"
+    When the NRC notification for that zaak is delivered to the event subscriber
+    And the same NRC notification is delivered again
+    Then the register projection contains exactly one row for "22222222-2222-2222-2222-222222222222"

tests/acceptance/Steps/RegisterProjectieBijwerkenSteps.cs

@@ -0,0 +1,48 @@
+using Acceptance.Support;
+using EventSubscriber.Application;
+using Reqnroll;
+using Xunit;
+
+namespace Acceptance.Steps;
+
+/// <summary>Bindings for <c>RegisterProjectieBijwerken.feature</c> (S-06). Reqnroll creates
+/// one instance per scenario, so instance fields hold scenario-scoped state.</summary>
+[Binding]
+public sealed class RegisterProjectieBijwerkenSteps
+{
+    private const string ZaakBase = "http://openzaak:8000/zaken/api/v1/zaken/";
+
+    private readonly InMemoryNotificationLog _log = new();
+    private readonly InMemoryProjectionStore _store = new();
+    private readonly NotificationProjector _projector;
+    private Notification? _notification;
+
+    public RegisterProjectieBijwerkenSteps() => _projector = new NotificationProjector(_log, _store);
+
+    [Given("a zaak is created in OpenZaak with id \"(.*)\"")]
+    public void GivenAZaakIsCreatedInOpenZaakWithId(string id)
+        => _notification = new Notification("zaken", "zaak", "create", new Uri(ZaakBase + id));
+
+    [When("the NRC notification for that zaak is delivered to the event subscriber")]
+    public Task WhenTheNotificationIsDelivered()
+        => _projector.HandleAsync(_notification!);
+
+    [When("the same NRC notification is delivered again")]
+    public Task WhenTheSameNotificationIsDeliveredAgain()
+        => _projector.HandleAsync(_notification!);
+
+    [Then("the register projection contains a row for \"(.*)\" with status \"(.*)\"")]
+    public async Task ThenTheProjectionContainsARowWithStatus(string id, string status)
+    {
+        var entry = Assert.Single(await _store.AllAsync());
+        Assert.Equal(id, entry.Id);
+        Assert.Equal(status, entry.Status);
+    }
+
+    [Then("the register projection contains exactly one row for \"(.*)\"")]
+    public async Task ThenTheProjectionContainsExactlyOneRowFor(string id)
+    {
+        await _store.AllAsync();
+        Assert.Single(_store.RowsFor(id));
+    }
+}

tests/acceptance/Support/InMemoryProjectionStores.cs

@@ -0,0 +1,40 @@
+using EventSubscriber.Application;
+
+namespace Acceptance.Support;
+
+/// <summary>In-memory stand-ins for the Event Subscriber's projection store and notification
+/// log, so the S-06 acceptance scenario runs without Postgres (real delivery is a live-stack
+/// check). Mirrors the <c>InMemoryZaakGateway</c> approach used for the ACL scenario.</summary>
+public sealed class InMemoryNotificationLog : INotificationLog
+{
+    private readonly Dictionary<string, RecordedNotification> _byKey = [];
+
+    public Task<bool> TryRecordAsync(RecordedNotification notification, CancellationToken ct = default)
+        => Task.FromResult(_byKey.TryAdd(notification.Key, notification));
+
+    public Task<IReadOnlyList<RecordedNotification>> AllAsync(CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<RecordedNotification>>([.. _byKey.Values]);
+}
+
+public sealed class InMemoryProjectionStore : IProjectionStore
+{
+    private readonly Dictionary<string, RegisterEntry> _byId = [];
+
+    public Task UpsertAsync(RegisterEntry entry, CancellationToken ct = default)
+    {
+        _byId[entry.Id] = entry;
+        return Task.CompletedTask;
+    }
+
+    public Task ClearAsync(CancellationToken ct = default)
+    {
+        _byId.Clear();
+        return Task.CompletedTask;
+    }
+
+    public Task<IReadOnlyList<RegisterEntry>> AllAsync(CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<RegisterEntry>>([.. _byId.Values]);
+
+    public IReadOnlyList<RegisterEntry> RowsFor(string id)
+        => [.. _byId.Values.Where(e => e.Id == id)];
+}