fix(site-event-logging): resolve SiteEventLogging-005,007,008,010 — background async writer, drop concrete downcast, surface write failures, test coverage

tests/ScadaLink.SiteEventLogging.Tests/EventLogHandlerActorTests.cs

@@ -0,0 +1,81 @@
+using Akka.Actor;
+using Akka.TestKit.Xunit2;
+using ScadaLink.Commons.Messages.RemoteQuery;
+
+namespace ScadaLink.SiteEventLogging.Tests;
+
+/// <summary>
+/// Regression tests for SiteEventLogging-010: the actor message contract of
+/// <see cref="EventLogHandlerActor"/> was previously untested.
+/// </summary>
+public class EventLogHandlerActorTests : TestKit
+{
+    /// <summary>Test double returning a canned response and recording the request.</summary>
+    private sealed class FakeQueryService : IEventLogQueryService
+    {
+        private readonly Func<EventLogQueryRequest, EventLogQueryResponse> _handler;
+        public EventLogQueryRequest? LastRequest { get; private set; }
+
+        public FakeQueryService(Func<EventLogQueryRequest, EventLogQueryResponse> handler)
+            => _handler = handler;
+
+        public EventLogQueryResponse ExecuteQuery(EventLogQueryRequest request)
+        {
+            LastRequest = request;
+            return _handler(request);
+        }
+    }
+
+    private static EventLogQueryRequest MakeRequest(string correlationId) => new(
+        CorrelationId: correlationId,
+        SiteId: "site-1",
+        From: null,
+        To: null,
+        EventType: null,
+        Severity: null,
+        InstanceId: null,
+        KeywordFilter: null,
+        ContinuationToken: null,
+        PageSize: 500,
+        Timestamp: DateTimeOffset.UtcNow);
+
+    private static EventLogQueryResponse MakeResponse(EventLogQueryRequest req, bool success = true) => new(
+        CorrelationId: req.CorrelationId,
+        SiteId: req.SiteId,
+        Entries: [],
+        ContinuationToken: null,
+        HasMore: false,
+        Success: success,
+        ErrorMessage: success ? null : "boom",
+        Timestamp: DateTimeOffset.UtcNow);
+
+    [Fact]
+    public void Actor_RepliesToSender_WithQueryResponse()
+    {
+        var fake = new FakeQueryService(req => MakeResponse(req));
+        var actor = Sys.ActorOf(Props.Create(() => new EventLogHandlerActor(fake)));
+
+        var request = MakeRequest("corr-1");
+        actor.Tell(request, TestActor);
+
+        var response = ExpectMsg<EventLogQueryResponse>();
+        Assert.Equal("corr-1", response.CorrelationId);
+        Assert.Equal("site-1", response.SiteId);
+        Assert.True(response.Success);
+        Assert.Same(request, fake.LastRequest);
+    }
+
+    [Fact]
+    public void Actor_PropagatesQueryServiceErrorResponse_ToSender()
+    {
+        var fake = new FakeQueryService(req => MakeResponse(req, success: false));
+        var actor = Sys.ActorOf(Props.Create(() => new EventLogHandlerActor(fake)));
+
+        actor.Tell(MakeRequest("corr-2"), TestActor);
+
+        var response = ExpectMsg<EventLogQueryResponse>();
+        Assert.False(response.Success);
+        Assert.Equal("corr-2", response.CorrelationId);
+        Assert.Equal("boom", response.ErrorMessage);
+    }
+}