feat(comms): IngestAuditEvents RPC + AuditEventDto proto (#23)

tests/ScadaLink.Communication.Tests/Protos/AuditEventProtoTests.cs

@@ -0,0 +1,123 @@
+using Google.Protobuf;
+using Google.Protobuf.WellKnownTypes;
+using ScadaLink.Communication.Grpc;
+
+namespace ScadaLink.Communication.Tests.Protos;
+
+/// <summary>
+/// Wire-format round-trip tests for the Audit Log (#23) telemetry proto messages
+/// (<see cref="AuditEventDto"/>, <see cref="AuditEventBatch"/>, <see cref="IngestAck"/>).
+/// Locks the additive contract the site → central audit pipeline depends on.
+/// </summary>
+public class AuditEventProtoTests
+{
+    [Fact]
+    public void AuditEventDto_RoundTrip_PreservesAllFields()
+    {
+        var occurredAt = Timestamp.FromDateTimeOffset(
+            new DateTimeOffset(2026, 5, 20, 10, 15, 30, 123, TimeSpan.Zero));
+
+        var original = new AuditEventDto
+        {
+            EventId = Guid.NewGuid().ToString(),
+            OccurredAtUtc = occurredAt,
+            Channel = "ApiOutbound",
+            Kind = "ApiCall",
+            CorrelationId = Guid.NewGuid().ToString(),
+            SourceSiteId = "site-1",
+            SourceInstanceId = "Pump01",
+            SourceScript = "OnDemand",
+            Actor = "design-key",
+            Target = "weather-api",
+            Status = "Delivered",
+            HttpStatus = 200,
+            DurationMs = 42,
+            ErrorMessage = "no error",
+            ErrorDetail = "stack",
+            RequestSummary = "GET /weather?city=brisbane",
+            ResponseSummary = "{ \"temp\": 22.5 }",
+            PayloadTruncated = true,
+            Extra = "{ \"retryCount\": 0 }"
+        };
+
+        var bytes = original.ToByteArray();
+        var deserialized = AuditEventDto.Parser.ParseFrom(bytes);
+
+        Assert.Equal(original.EventId, deserialized.EventId);
+        Assert.Equal(original.OccurredAtUtc, deserialized.OccurredAtUtc);
+        Assert.Equal(original.Channel, deserialized.Channel);
+        Assert.Equal(original.Kind, deserialized.Kind);
+        Assert.Equal(original.CorrelationId, deserialized.CorrelationId);
+        Assert.Equal(original.SourceSiteId, deserialized.SourceSiteId);
+        Assert.Equal(original.SourceInstanceId, deserialized.SourceInstanceId);
+        Assert.Equal(original.SourceScript, deserialized.SourceScript);
+        Assert.Equal(original.Actor, deserialized.Actor);
+        Assert.Equal(original.Target, deserialized.Target);
+        Assert.Equal(original.Status, deserialized.Status);
+        Assert.Equal(original.HttpStatus, deserialized.HttpStatus);
+        Assert.Equal(original.DurationMs, deserialized.DurationMs);
+        Assert.Equal(original.ErrorMessage, deserialized.ErrorMessage);
+        Assert.Equal(original.ErrorDetail, deserialized.ErrorDetail);
+        Assert.Equal(original.RequestSummary, deserialized.RequestSummary);
+        Assert.Equal(original.ResponseSummary, deserialized.ResponseSummary);
+        Assert.Equal(original.PayloadTruncated, deserialized.PayloadTruncated);
+        Assert.Equal(original.Extra, deserialized.Extra);
+    }
+
+    [Fact]
+    public void AuditEventDto_NullableInt_AbsentByDefault_NotIncludedInWire()
+    {
+        // Int32Value fields (http_status, duration_ms) are wrapper-typed in proto;
+        // when unset, the wrapper is absent, not serialized, and deserializes back to null.
+        var original = new AuditEventDto
+        {
+            EventId = Guid.NewGuid().ToString(),
+            OccurredAtUtc = Timestamp.FromDateTimeOffset(DateTimeOffset.UtcNow),
+            Channel = "Notification",
+            Kind = "NotifySend",
+            Status = "Submitted"
+        };
+
+        Assert.Null(original.HttpStatus);
+        Assert.Null(original.DurationMs);
+
+        var bytes = original.ToByteArray();
+        var deserialized = AuditEventDto.Parser.ParseFrom(bytes);
+
+        Assert.Null(deserialized.HttpStatus);
+        Assert.Null(deserialized.DurationMs);
+    }
+
+    [Fact]
+    public void AuditEventBatch_Empty_RoundTrip_Yields_EmptyEvents()
+    {
+        var original = new AuditEventBatch();
+        Assert.Empty(original.Events);
+
+        var bytes = original.ToByteArray();
+        var deserialized = AuditEventBatch.Parser.ParseFrom(bytes);
+
+        Assert.Empty(deserialized.Events);
+    }
+
+    [Fact]
+    public void IngestAck_PreservesAcceptedEventIds()
+    {
+        var id1 = Guid.NewGuid().ToString();
+        var id2 = Guid.NewGuid().ToString();
+        var id3 = Guid.NewGuid().ToString();
+
+        var original = new IngestAck();
+        original.AcceptedEventIds.Add(id1);
+        original.AcceptedEventIds.Add(id2);
+        original.AcceptedEventIds.Add(id3);
+
+        var bytes = original.ToByteArray();
+        var deserialized = IngestAck.Parser.ParseFrom(bytes);
+
+        Assert.Equal(3, deserialized.AcceptedEventIds.Count);
+        Assert.Equal(id1, deserialized.AcceptedEventIds[0]);
+        Assert.Equal(id2, deserialized.AcceptedEventIds[1]);
+        Assert.Equal(id3, deserialized.AcceptedEventIds[2]);
+    }
+}