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/ServiceWiringTests.cs

@@ -0,0 +1,71 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace ScadaLink.SiteEventLogging.Tests;
+
+/// <summary>
+/// Regression tests for SiteEventLogging-007: the purge and query services must not
+/// downcast an injected <see cref="ISiteEventLogger"/> to the concrete type. They now
+/// depend on the concrete <see cref="SiteEventLogger"/> directly, and DI must resolve
+/// the recorder, query service, and purge service to a single shared instance.
+/// </summary>
+public class ServiceWiringTests : IDisposable
+{
+    private readonly string _dbPath;
+    private ServiceProvider? _provider;
+
+    public ServiceWiringTests()
+    {
+        _dbPath = Path.Combine(Path.GetTempPath(), $"test_wiring_{Guid.NewGuid()}.db");
+    }
+
+    public void Dispose()
+    {
+        _provider?.Dispose();
+        if (File.Exists(_dbPath)) File.Delete(_dbPath);
+    }
+
+    [Fact]
+    public void AddSiteEventLogging_ResolvesAllServices_SharingOneRecorderInstance()
+    {
+        var services = new ServiceCollection();
+        services.AddLogging();
+        services.Configure<SiteEventLogOptions>(o => o.DatabasePath = _dbPath);
+        services.AddSiteEventLogging();
+
+        _provider = services.BuildServiceProvider();
+
+        var recorderViaInterface = _provider.GetRequiredService<ISiteEventLogger>();
+        var recorderConcrete = _provider.GetRequiredService<SiteEventLogger>();
+        var queryService = _provider.GetRequiredService<IEventLogQueryService>();
+
+        // The interface registration must forward to the concrete singleton — purge
+        // and query depend on that same instance, so all three share one connection.
+        Assert.Same(recorderConcrete, recorderViaInterface);
+        Assert.NotNull(queryService);
+
+        // The hosted purge service must also resolve without an InvalidCastException.
+        var hosted = _provider.GetServices<Microsoft.Extensions.Hosting.IHostedService>();
+        Assert.Contains(hosted, h => h is EventLogPurgeService);
+    }
+
+    [Fact]
+    public void PurgeAndQueryServices_AcceptConcreteRecorder_WithoutDowncast()
+    {
+        // The services no longer take ISiteEventLogger and downcast it; they take the
+        // concrete SiteEventLogger. Constructing them directly must compile and work.
+        var options = Options.Create(new SiteEventLogOptions { DatabasePath = _dbPath });
+        using var loggerFactory = LoggerFactory.Create(_ => { });
+        using var recorder = new SiteEventLogger(
+            options, loggerFactory.CreateLogger<SiteEventLogger>());
+
+        var purge = new EventLogPurgeService(
+            recorder, options, loggerFactory.CreateLogger<EventLogPurgeService>());
+        var query = new EventLogQueryService(
+            recorder, options, loggerFactory.CreateLogger<EventLogQueryService>());
+
+        Assert.NotNull(purge);
+        Assert.NotNull(query);
+    }
+}