review(Core.Abstractions): document ReadEventsAsync continuation contract (OpcUaServer-002 root)

Re-review at 7286d320. Core.Abstractions-009: ReadEventsAsync maxEvents<=0 sentinel now documents the implementer's continuation-point obligation when a backend cap truncates (the root of OpcUaServer-002). -010: PollGroupEngineTests pass CancellationToken. Plus EquipmentTagRefResolver.TryResolve [MaybeNullWhen(false)] NRT cleanup + test.
2026-06-19 11:06:56 -04:00
parent 354b0e7613
commit 65e6af6001
7 changed files with 135 additions and 12 deletions
@@ -169,6 +169,33 @@ public sealed class IHistorianDataSourceContractTests
        parameter!.ParameterType.ShouldBe(expectedType);
    }

+    /// <summary>
+    ///     Core.Abstractions-009 (OpcUaServer-002): when <c>maxEvents &lt;= 0</c> the contract
+    ///     requires implementations to set <see cref="HistoricalEventsResult.ContinuationPoint"/>
+    ///     non-null when more results exist. Pins the <c>maxEvents</c> parameter type and the
+    ///     <see cref="HistoricalEventsResult"/> continuation-point member so accidental removal
+    ///     breaks this test — the downstream paging contract depends on both.
+    /// </summary>
+    [Fact]
+    public void ReadEventsAsync_sentinel_and_continuation_contract_types_pinned()
+    {
+        var method = typeof(IHistorianDataSource).GetMethod("ReadEventsAsync");
+        method.ShouldNotBeNull();
+
+        var maxEventsParam = method!.GetParameters().FirstOrDefault(p => p.Name == "maxEvents");
+        maxEventsParam.ShouldNotBeNull("maxEvents parameter must exist for the sentinel contract");
+        maxEventsParam!.ParameterType.ShouldBe(typeof(int),
+            "maxEvents is int (not uint) so callers can pass <=0 as a 'use backend default cap' sentinel");
+
+        // HistoricalEventsResult must carry a nullable ContinuationPoint so implementations
+        // can signal 'more results exist' (non-null) vs 'all results returned' (null).
+        var resultType = typeof(HistoricalEventsResult);
+        var continuationProp = resultType.GetProperty("ContinuationPoint");
+        continuationProp.ShouldNotBeNull("HistoricalEventsResult.ContinuationPoint must exist for paging");
+        continuationProp!.PropertyType.ShouldBe(typeof(byte[]),
+            "ContinuationPoint is byte[]? — null means no more pages, non-null means caller must page");
+    }
+
    /// <summary>
    ///     Core.Abstractions-008: <see cref="IHistoryProvider.ReadAtTimeAsync"/> and
    ///     <see cref="IHistoryProvider.ReadEventsAsync"/> are C# default interface methods