From c51ca2276b6093efca0281303aa5c2b614d974de Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Fri, 26 Jun 2026 16:35:08 -0400
Subject: [PATCH] fix(historian-gateway): seam maxEvents XML doc + driver
 Platforms + ValueTask in fake

Addresses Task 1 code-review: document that ReadEventsAsync.maxEvents is enforced
client-side (no server cap in the wire contract); add Platforms=AnyCPU;x64 to match
sibling drivers; use ValueTask.CompletedTask in FakeHistorianGatewayClient.

Claude-Session: https://claude.ai/code/session_012SDSQ3AcaXqPcBtDESBRii
---
 .../IHistorianGatewayClient.cs                         | 10 ++++++++++
 .../ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj  |  1 +
 .../FakeHistorianGatewayClient.cs                      |  2 +-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/IHistorianGatewayClient.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/IHistorianGatewayClient.cs
index efb969a4..e11bad58 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/IHistorianGatewayClient.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/IHistorianGatewayClient.cs
@@ -35,6 +35,16 @@ public interface IHistorianGatewayClient : IAsyncDisposable
         CancellationToken ct);
 
     /// <summary>Streams historian events over a window, optionally filtered to a single source name.</summary>
+    /// <param name="sourceName">Optional source-name filter; <c>null</c> returns events from all sources.</param>
+    /// <param name="startUtc">Inclusive start of the time window (UTC).</param>
+    /// <param name="endUtc">Exclusive end of the time window (UTC).</param>
+    /// <param name="maxEvents">
+    /// Caps the number of events returned. The gateway wire contract (<c>ReadEventsRequest</c>) has
+    /// no per-call server cap, so this limit is enforced client-side by early stream termination:
+    /// <c>0</c> or negative means no client-side limit (the gateway may still apply its configured
+    /// <c>RuntimeDb:EventReadMaxRows</c>); a positive value stops draining after that many events.
+    /// </param>
+    /// <param name="ct">Cancellation token.</param>
     IAsyncEnumerable<HistorianEvent> ReadEventsAsync(
         string? sourceName,
         DateTime startUtc,
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj
index aad1040c..1f2994d9 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.csproj
@@ -4,6 +4,7 @@
         <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
         <GenerateDocumentationFile>true</GenerateDocumentationFile>
         <NoWarn>$(NoWarn);CS1591</NoWarn>
+        <Platforms>AnyCPU;x64</Platforms>
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway</RootNamespace>
     </PropertyGroup>
 
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/FakeHistorianGatewayClient.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/FakeHistorianGatewayClient.cs
index 1eda81d0..38f78ae4 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/FakeHistorianGatewayClient.cs
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests/FakeHistorianGatewayClient.cs
@@ -209,6 +209,6 @@ public sealed class FakeHistorianGatewayClient : IHistorianGatewayClient
             yield return item;
         }
 
-        await Task.CompletedTask.ConfigureAwait(false);
+        await ValueTask.CompletedTask.ConfigureAwait(false);
     }
 }