fix(health-monitoring): resolve HealthMonitoring-001/002 — populate S&F buffer depth, make SiteHealthState immutable

tests/ScadaLink.HealthMonitoring.Tests/HealthReportSenderTests.cs

@@ -1,7 +1,9 @@
+using Microsoft.Data.Sqlite;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using ScadaLink.Commons.Messages.Health;
 using ScadaLink.Commons.Types.Enums;
+using ScadaLink.StoreAndForward;
 
 namespace ScadaLink.HealthMonitoring.Tests;
 
@@ -136,6 +138,76 @@ public class HealthReportSenderTests
         }
     }
 
+    /// <summary>
+    /// HealthMonitoring-001 regression: the documented "store-and-forward buffer
+    /// depth" metric (pending messages by category) must actually be populated in
+    /// the emitted report. Previously SetStoreAndForwardDepths had no callers, so
+    /// StoreAndForwardBufferDepths was always empty. The sender must query the S&amp;F
+    /// engine's per-category depth API and include it alongside the parked count.
+    /// </summary>
+    [Fact]
+    public async Task ReportsIncludeStoreAndForwardBufferDepthsFromStorage()
+    {
+        var dbName = $"HealthSfDepth_{Guid.NewGuid():N}";
+        var connStr = $"Data Source={dbName};Mode=Memory;Cache=Shared";
+        // Keep one connection alive so the in-memory DB persists for the test.
+        using var keepAlive = new SqliteConnection(connStr);
+        keepAlive.Open();
+
+        var storage = new StoreAndForwardStorage(connStr, NullLogger<StoreAndForwardStorage>.Instance);
+        await storage.InitializeAsync();
+
+        // Two pending ExternalSystem messages and one pending Notification message.
+        await storage.EnqueueAsync(MakePendingMessage("m1", StoreAndForwardCategory.ExternalSystem));
+        await storage.EnqueueAsync(MakePendingMessage("m2", StoreAndForwardCategory.ExternalSystem));
+        await storage.EnqueueAsync(MakePendingMessage("m3", StoreAndForwardCategory.Notification));
+
+        var transport = new FakeTransport();
+        var collector = new SiteHealthCollector();
+        collector.SetActiveNode(true);
+        var options = Options.Create(new HealthMonitoringOptions
+        {
+            ReportInterval = TimeSpan.FromMilliseconds(50)
+        });
+
+        var sender = new HealthReportSender(
+            collector,
+            transport,
+            options,
+            NullLogger<HealthReportSender>.Instance,
+            new FakeSiteIdentityProvider(),
+            sfStorage: storage);
+
+        using var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(300));
+        try
+        {
+            await sender.StartAsync(cts.Token);
+            await Task.Delay(250, CancellationToken.None);
+            await sender.StopAsync(CancellationToken.None);
+        }
+        catch (OperationCanceledException) { }
+
+        Assert.True(transport.SentReports.Count >= 1);
+        var depths = transport.SentReports[^1].StoreAndForwardBufferDepths;
+        Assert.Equal(2, depths[nameof(StoreAndForwardCategory.ExternalSystem)]);
+        Assert.Equal(1, depths[nameof(StoreAndForwardCategory.Notification)]);
+        Assert.False(depths.ContainsKey(nameof(StoreAndForwardCategory.CachedDbWrite)));
+    }
+
+    private static StoreAndForwardMessage MakePendingMessage(string id, StoreAndForwardCategory category) =>
+        new()
+        {
+            Id = id,
+            Category = category,
+            Target = "target",
+            PayloadJson = "{}",
+            RetryCount = 0,
+            MaxRetries = 50,
+            RetryIntervalMs = 30_000,
+            CreatedAt = DateTimeOffset.UtcNow,
+            Status = StoreAndForwardMessageStatus.Pending
+        };
+
     [Fact]
     public void InitialSequenceNumberSeededWithUnixMs()
     {