feat(dashboard): in-process session event subscription feeds the viewer registry — SessionDetailsPage drops its /hubs/events hop

2026-08-15 20:15:52 -04:00
parent d44fe1d6b5
commit e23f816bfb
5 changed files with 501 additions and 58 deletions
@@ -121,6 +121,140 @@ public sealed class DashboardEventBroadcasterTests
        Assert.NotNull(sent.OnAlarmTransition.LimitValue);
    }

+    /// <summary>
+    /// An in-process subscriber gets the same redacted clone the hub group gets,
+    /// and the shared source event is still left untouched.
+    /// </summary>
+    [Fact]
+    public void Subscribe_WhenShowTagValuesFalse_DeliversRedactedCloneWithoutMutatingSource()
+    {
+        CapturingHubContext hubContext = new();
+        EventsHubViewerRegistry viewers = new();
+        DashboardEventBroadcaster broadcaster = Create(hubContext, showTagValues: false, viewers);
+        using IDashboardEventSubscription subscription = broadcaster.Subscribe("session-1");
+        MxEvent source = BuildEventWithValue();
+
+        broadcaster.Publish("session-1", source);
+
+        MxEvent received = ReadOne(subscription);
+        Assert.Null(received.Value);
+        Assert.Null(received.OnAlarmTransition.CurrentValue);
+        Assert.Null(received.OnAlarmTransition.LimitValue);
+        Assert.Equal("Tank01.Level.HiHi", received.OnAlarmTransition.AlarmFullReference);
+
+        // One clone feeds both audiences — the hub group and the in-process feed.
+        Assert.Same(hubContext.LastArgument, received);
+
+        // The source is shared with the gRPC stream and the replay ring.
+        Assert.NotSame(source, received);
+        Assert.NotNull(source.Value);
+        Assert.Equal(42.5, source.Value.DoubleValue);
+        Assert.NotNull(source.OnAlarmTransition.CurrentValue);
+        Assert.NotNull(source.OnAlarmTransition.LimitValue);
+    }
+
+    /// <summary>An in-process subscription opens the viewer gate the same way a hub client does.</summary>
+    [Fact]
+    public void Subscribe_OpensTheViewerGate()
+    {
+        CapturingHubContext hubContext = new();
+        EventsHubViewerRegistry viewers = new();
+        DashboardEventBroadcaster broadcaster = Create(hubContext, showTagValues: false, viewers);
+
+        broadcaster.Publish("session-1", BuildEventWithValue());
+        Assert.Equal(0, hubContext.SendCount);
+        Assert.Null(hubContext.LastArgument);
+
+        using IDashboardEventSubscription subscription = broadcaster.Subscribe("session-1");
+
+        Assert.True(viewers.HasViewers("session-1"));
+
+        broadcaster.Publish("session-1", BuildEventWithValue());
+
+        Assert.Equal(1, hubContext.SendCount);
+        Assert.NotNull(hubContext.LastArgument);
+    }
+
+    /// <summary>Disposing the last in-process subscription restores the no-viewers short-circuit.</summary>
+    [Fact]
+    public void Dispose_OfLastInProcessSubscription_RestoresTheShortCircuit()
+    {
+        CapturingHubContext hubContext = new();
+        EventsHubViewerRegistry viewers = new();
+        DashboardEventBroadcaster broadcaster = Create(hubContext, showTagValues: false, viewers);
+        IDashboardEventSubscription subscription = broadcaster.Subscribe("session-1");
+
+        broadcaster.Publish("session-1", BuildEventWithValue());
+        Assert.Equal(1, hubContext.SendCount);
+        Assert.Equal("session-1", ReadOne(subscription).SessionId);
+
+        subscription.Dispose();
+
+        Assert.False(viewers.HasViewers("session-1"));
+
+        broadcaster.Publish("session-1", BuildEventWithValue());
+
+        Assert.Equal(1, hubContext.SendCount);
+        Assert.False(subscription.Reader.TryRead(out _));
+    }
+
+    /// <summary>Hub viewers and in-process subscribers are audiences of their own session only.</summary>
+    [Fact]
+    public void Publish_DeliversOnlyToTheSubscribedSessionsAudience()
+    {
+        CapturingHubContext hubContext = new();
+        EventsHubViewerRegistry viewers = new();
+        viewers.AddViewer("conn-1", "session-1");
+        DashboardEventBroadcaster broadcaster = Create(hubContext, showTagValues: false, viewers);
+        using IDashboardEventSubscription subscription = broadcaster.Subscribe("session-2");
+
+        // The hub viewer's session must not spill into the in-process feed.
+        broadcaster.Publish("session-1", BuildEventWithValue());
+
+        Assert.Equal(1, hubContext.SendCount);
+        Assert.False(subscription.Reader.TryRead(out _));
+
+        broadcaster.Publish("session-2", BuildEventWithValue("session-2"));
+
+        Assert.Equal("session-2", ReadOne(subscription).SessionId);
+
+        // A session with no audience at all still short-circuits.
+        broadcaster.Publish("session-3", BuildEventWithValue("session-3"));
+
+        Assert.Equal(2, hubContext.SendCount);
+    }
+
+    /// <summary>Disposing twice is a no-op and cannot release a sibling subscription's registration.</summary>
+    [Fact]
+    public void Dispose_CalledTwice_IsSafeAndLeavesSiblingSubscriptionsAlone()
+    {
+        CapturingHubContext hubContext = new();
+        EventsHubViewerRegistry viewers = new();
+        DashboardEventBroadcaster broadcaster = Create(hubContext, showTagValues: false, viewers);
+        IDashboardEventSubscription first = broadcaster.Subscribe("session-1");
+        using IDashboardEventSubscription second = broadcaster.Subscribe("session-1");
+
+        first.Dispose();
+        first.Dispose();
+
+        Assert.True(viewers.HasViewers("session-1"));
+
+        broadcaster.Publish("session-1", BuildEventWithValue());
+
+        Assert.Equal(1, hubContext.SendCount);
+        Assert.False(first.Reader.TryRead(out _));
+        Assert.Equal("session-1", ReadOne(second).SessionId);
+    }
+
+    /// <summary>Reads exactly one event from a subscription, failing the test if none is queued.</summary>
+    /// <param name="subscription">The subscription to read from.</param>
+    /// <returns>The event that was read.</returns>
+    private static MxEvent ReadOne(IDashboardEventSubscription subscription)
+    {
+        Assert.True(subscription.Reader.TryRead(out MxEvent? received));
+        return Assert.IsType<MxEvent>(received);
+    }
+
    private static DashboardEventBroadcaster Create(
        CapturingHubContext hubContext,
        bool showTagValues,
@@ -147,12 +281,15 @@ public sealed class DashboardEventBroadcasterTests
        return viewers;
    }

-    private static MxEvent BuildEventWithValue()
+    /// <summary>Builds a value-bearing alarm-transition event for the given session.</summary>
+    /// <param name="sessionId">Session id stamped on the event.</param>
+    /// <returns>The event.</returns>
+    private static MxEvent BuildEventWithValue(string sessionId = "session-1")
    {
        return new MxEvent
        {
            Family = MxEventFamily.OnAlarmTransition,
-            SessionId = "session-1",
+            SessionId = sessionId,
            ServerHandle = 7,
            ItemHandle = 11,
            Quality = 192,