feat(historian): HistoryRead override (Raw/Processed/AtTime) over IHistorianDataSource

2026-06-14 19:31:39 -04:00
parent 50e1141fc2
commit 13fba8f8fb
4 changed files with 910 additions and 0 deletions
@@ -0,0 +1,100 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests.Historian;
+
+/// <summary>
+///     The default no-op historian source. Every read returns an empty result with a null
+///     continuation point; <see cref="NullHistorianDataSource.GetHealthSnapshot"/> reports a fully
+///     disabled shape; and <see cref="NullHistorianDataSource.Instance"/> is the shared singleton.
+/// </summary>
+public sealed class NullHistorianDataSourceTests
+{
+    private static CancellationToken Ct => TestContext.Current.CancellationToken;
+
+    private static readonly NullHistorianDataSource Source = NullHistorianDataSource.Instance;
+
+    /// <summary><see cref="NullHistorianDataSource.Instance"/> is a single shared instance.</summary>
+    [Fact]
+    public void Instance_is_a_singleton()
+    {
+        NullHistorianDataSource.Instance.ShouldBeSameAs(NullHistorianDataSource.Instance);
+    }
+
+    /// <summary>ReadRawAsync returns no samples and a null continuation point.</summary>
+    [Fact]
+    public async Task ReadRawAsync_returns_empty()
+    {
+        var result = await Source.ReadRawAsync(
+            "WW.Tag", DateTime.UtcNow.AddHours(-1), DateTime.UtcNow, maxValuesPerNode: 100, Ct);
+
+        result.Samples.ShouldBeEmpty();
+        result.ContinuationPoint.ShouldBeNull();
+    }
+
+    /// <summary>ReadProcessedAsync returns no samples and a null continuation point.</summary>
+    [Fact]
+    public async Task ReadProcessedAsync_returns_empty()
+    {
+        var result = await Source.ReadProcessedAsync(
+            "WW.Tag", DateTime.UtcNow.AddHours(-1), DateTime.UtcNow,
+            TimeSpan.FromSeconds(10), HistoryAggregateType.Average, Ct);
+
+        result.Samples.ShouldBeEmpty();
+        result.ContinuationPoint.ShouldBeNull();
+    }
+
+    /// <summary>ReadAtTimeAsync returns no samples and a null continuation point.</summary>
+    [Fact]
+    public async Task ReadAtTimeAsync_returns_empty()
+    {
+        var result = await Source.ReadAtTimeAsync(
+            "WW.Tag", new[] { DateTime.UtcNow }, Ct);
+
+        result.Samples.ShouldBeEmpty();
+        result.ContinuationPoint.ShouldBeNull();
+    }
+
+    /// <summary>ReadEventsAsync returns no events and a null continuation point.</summary>
+    [Fact]
+    public async Task ReadEventsAsync_returns_empty()
+    {
+        var result = await Source.ReadEventsAsync(
+            sourceName: null, DateTime.UtcNow.AddHours(-1), DateTime.UtcNow, maxEvents: 0, Ct);
+
+        result.Events.ShouldBeEmpty();
+        result.ContinuationPoint.ShouldBeNull();
+    }
+
+    /// <summary>GetHealthSnapshot reports a fully-disabled (zeroed, disconnected, no-node) shape.</summary>
+    [Fact]
+    public void GetHealthSnapshot_is_disabled()
+    {
+        var snapshot = Source.GetHealthSnapshot();
+
+        snapshot.TotalQueries.ShouldBe(0);
+        snapshot.TotalSuccesses.ShouldBe(0);
+        snapshot.TotalFailures.ShouldBe(0);
+        snapshot.ConsecutiveFailures.ShouldBe(0);
+        snapshot.LastSuccessTime.ShouldBeNull();
+        snapshot.LastFailureTime.ShouldBeNull();
+        snapshot.LastError.ShouldBeNull();
+        snapshot.ProcessConnectionOpen.ShouldBeFalse();
+        snapshot.EventConnectionOpen.ShouldBeFalse();
+        snapshot.ActiveProcessNode.ShouldBeNull();
+        snapshot.ActiveEventNode.ShouldBeNull();
+        snapshot.Nodes.ShouldBeEmpty();
+    }
+
+    /// <summary>Dispose is a safe no-op (idempotent).</summary>
+    [Fact]
+    public void Dispose_is_a_noop()
+    {
+        Should.NotThrow(() =>
+        {
+            Source.Dispose();
+            Source.Dispose();
+        });
+    }
+}