docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/ClientStoragePathsTests.cs

@@ -7,6 +7,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests;
 [Trait("Category", "Unit")]
 public sealed class ClientStoragePathsTests
 {
+    /// <summary>Verifies that GetRoot returns the canonical folder name under LocalAppData.</summary>
     [Fact]
     public void GetRoot_ReturnsCanonicalFolderName_UnderLocalAppData()
     {
@@ -15,6 +16,7 @@ public sealed class ClientStoragePathsTests
         root.ShouldContain(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData));
     }
 
+    /// <summary>Verifies that GetPkiPath nests PKI under root.</summary>
     [Fact]
     public void GetPkiPath_NestsPkiUnderRoot()
     {
@@ -22,12 +24,14 @@ public sealed class ClientStoragePathsTests
         pki.ShouldEndWith(Path.Combine(ClientStoragePaths.CanonicalFolderName, "pki"));
     }
 
+    /// <summary>Verifies that CanonicalFolderName is OtOpcUaClient.</summary>
     [Fact]
     public void CanonicalFolderName_IsOtOpcUaClient()
     {
         ClientStoragePaths.CanonicalFolderName.ShouldBe("OtOpcUaClient");
     }
 
+    /// <summary>Verifies that LegacyFolderName is LmxOpcUaClient.</summary>
     [Fact]
     public void LegacyFolderName_IsLmxOpcUaClient()
     {
@@ -36,6 +40,7 @@ public sealed class ClientStoragePathsTests
         ClientStoragePaths.LegacyFolderName.ShouldBe("LmxOpcUaClient");
     }
 
+    /// <summary>Verifies that TryRunLegacyMigration returns false on repeat invocation.</summary>
     [Fact]
     public void TryRunLegacyMigration_Returns_False_On_Repeat_Invocation()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeApplicationConfigurationFactory.cs

@@ -6,10 +6,16 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Fakes;
 
 internal sealed class FakeApplicationConfigurationFactory : IApplicationConfigurationFactory
 {
+    /// <summary>Gets or sets a value indicating whether to throw when Create is called.</summary>
     public bool ThrowOnCreate { get; set; }
+
+    /// <summary>Gets the number of times CreateAsync has been called.</summary>
     public int CreateCallCount { get; private set; }
+
+    /// <summary>Gets the last connection settings passed to CreateAsync.</summary>
     public ConnectionSettings? LastSettings { get; private set; }
 
+    /// <inheritdoc />
     public Task<ApplicationConfiguration> CreateAsync(ConnectionSettings settings, CancellationToken ct)
     {
         CreateCallCount++;

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeEndpointDiscovery.cs

@@ -5,10 +5,18 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Fakes;
 
 internal sealed class FakeEndpointDiscovery : IEndpointDiscovery
 {
+    /// <summary>Gets or sets a value indicating whether SelectEndpoint should throw an exception.</summary>
     public bool ThrowOnSelect { get; set; }
+    /// <summary>Gets the number of times SelectEndpoint has been called.</summary>
     public int SelectCallCount { get; private set; }
+    /// <summary>Gets the last endpoint URL passed to SelectEndpoint.</summary>
     public string? LastEndpointUrl { get; private set; }
 
+    /// <summary>Selects an endpoint for the given configuration and URL, optionally throwing an exception.</summary>
+    /// <param name="config">The application configuration.</param>
+    /// <param name="endpointUrl">The endpoint URL to select.</param>
+    /// <param name="requestedMode">The requested security mode.</param>
+    /// <returns>The selected endpoint description.</returns>
     public EndpointDescription SelectEndpoint(ApplicationConfiguration config, string endpointUrl,
         MessageSecurityMode requestedMode)
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeSessionAdapter.cs

@@ -20,31 +20,53 @@ internal sealed class FakeSessionAdapter : ISessionAdapter
     /// Gets a value indicating whether the fake session has been disposed.
     /// </summary>
     public bool Disposed { get; private set; }
+    /// <summary>Gets the number of times ReadValueAsync has been called.</summary>
     public int ReadCount { get; private set; }
+    /// <summary>Gets the number of times WriteValueAsync has been called.</summary>
     public int WriteCount { get; private set; }
+    /// <summary>Gets the number of times BrowseAsync has been called.</summary>
     public int BrowseCount { get; private set; }
+    /// <summary>Gets the number of times BrowseNextAsync has been called.</summary>
     public int BrowseNextCount { get; private set; }
+    /// <summary>Gets the number of times HasChildrenAsync has been called.</summary>
     public int HasChildrenCount { get; private set; }
+    /// <summary>Gets the number of times HistoryReadRawAsync has been called.</summary>
     public int HistoryReadRawCount { get; private set; }
+    /// <summary>Gets the number of times HistoryReadAggregateAsync has been called.</summary>
     public int HistoryReadAggregateCount { get; private set; }
 
     // Configurable responses
+    /// <summary>Gets or sets the data value returned by read operations.</summary>
     public DataValue? ReadResponse { get; set; }
+    /// <summary>Gets or sets a function to generate read responses dynamically based on the node ID.</summary>
     public Func<NodeId, DataValue>? ReadResponseFunc { get; set; }
+    /// <summary>Gets or sets the status code returned by write operations.</summary>
     public StatusCode WriteResponse { get; set; } = StatusCodes.Good;
+    /// <summary>Gets or sets a value indicating whether read operations should throw an exception.</summary>
     public bool ThrowOnRead { get; set; }
+    /// <summary>Gets or sets a value indicating whether write operations should throw an exception.</summary>
     public bool ThrowOnWrite { get; set; }
+    /// <summary>Gets or sets a value indicating whether browse operations should throw an exception.</summary>
     public bool ThrowOnBrowse { get; set; }
 
+    /// <summary>Gets or sets the browse references returned by browse operations.</summary>
     public ReferenceDescriptionCollection BrowseResponse { get; set; } = [];
+    /// <summary>Gets or sets the continuation point for browse operations.</summary>
     public byte[]? BrowseContinuationPoint { get; set; }
+    /// <summary>Gets or sets the browse references returned by browse-next operations.</summary>
     public ReferenceDescriptionCollection BrowseNextResponse { get; set; } = [];
+    /// <summary>Gets or sets the continuation point for browse-next operations.</summary>
     public byte[]? BrowseNextContinuationPoint { get; set; }
+    /// <summary>Gets or sets the result returned by has-children operations.</summary>
     public bool HasChildrenResponse { get; set; } = false;
 
+    /// <summary>Gets or sets the historical values returned by raw history-read operations.</summary>
     public List<DataValue> HistoryReadRawResponse { get; set; } = [];
+    /// <summary>Gets or sets the historical values returned by aggregate history-read operations.</summary>
     public List<DataValue> HistoryReadAggregateResponse { get; set; } = [];
+    /// <summary>Gets or sets a value indicating whether raw history-read operations should throw an exception.</summary>
     public bool ThrowOnHistoryReadRaw { get; set; }
+    /// <summary>Gets or sets a value indicating whether aggregate history-read operations should throw an exception.</summary>
     public bool ThrowOnHistoryReadAggregate { get; set; }
 
     /// <summary>
@@ -210,6 +232,7 @@ internal sealed class FakeSessionAdapter : ISessionAdapter
     /// <summary>
     ///     Simulates a keep-alive event.
     /// </summary>
+    /// <param name="isGood">Whether the keep-alive status is good.</param>
     public void SimulateKeepAlive(bool isGood)
     {
         _keepAliveCallback?.Invoke(isGood);

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeSessionFactory.cs

@@ -8,8 +8,11 @@ internal sealed class FakeSessionFactory : ISessionFactory
     private readonly List<FakeSessionAdapter> _createdSessions = [];
     private readonly Queue<FakeSessionAdapter> _sessions = new();
 
+    /// <summary>Gets the number of times CreateSessionAsync has been called.</summary>
     public int CreateCallCount { get; private set; }
+    /// <summary>Gets or sets a value indicating whether CreateSessionAsync should throw.</summary>
     public bool ThrowOnCreate { get; set; }
+    /// <summary>Gets the endpoint URL from the last CreateSessionAsync call.</summary>
     public string? LastEndpointUrl { get; private set; }
 
     /// <summary>
@@ -18,8 +21,17 @@ internal sealed class FakeSessionFactory : ISessionFactory
     /// </summary>
     public TaskCompletionSource? CreateGate { get; set; }
 
+    /// <summary>Gets the list of sessions created via CreateSessionAsync.</summary>
     public IReadOnlyList<FakeSessionAdapter> CreatedSessions => _createdSessions;
 
+    /// <summary>Creates a session asynchronously (fake implementation).</summary>
+    /// <param name="config">The application configuration.</param>
+    /// <param name="endpoint">The endpoint description.</param>
+    /// <param name="sessionName">The session name.</param>
+    /// <param name="sessionTimeoutMs">The session timeout in milliseconds.</param>
+    /// <param name="identity">The user identity.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A task containing the session adapter.</returns>
     public async Task<ISessionAdapter> CreateSessionAsync(
         ApplicationConfiguration config, EndpointDescription endpoint, string sessionName,
         uint sessionTimeoutMs, UserIdentity identity, CancellationToken ct)
@@ -54,6 +66,7 @@ internal sealed class FakeSessionFactory : ISessionFactory
     /// <summary>
     ///     Enqueues a session adapter to be returned on the next call to CreateSessionAsync.
     /// </summary>
+    /// <param name="session">The session adapter to enqueue.</param>
     public void EnqueueSession(FakeSessionAdapter session)
     {
         _sessions.Enqueue(session);

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeSubscriptionAdapter.cs

@@ -31,8 +31,13 @@ internal sealed class FakeSubscriptionAdapter : ISubscriptionAdapter
     /// Gets or sets a value indicating whether condition refresh should throw to simulate unsupported servers.
     /// </summary>
     public bool ThrowOnConditionRefresh { get; set; }
+    /// <summary>Gets the number of times AddDataChangeMonitoredItemAsync was called.</summary>
     public int AddDataChangeCount { get; private set; }
+
+    /// <summary>Gets the number of times AddEventMonitoredItemAsync was called.</summary>
     public int AddEventCount { get; private set; }
+
+    /// <summary>Gets the number of times RemoveMonitoredItemAsync was called.</summary>
     public int RemoveCount { get; private set; }
 
     /// <summary>
@@ -115,6 +120,8 @@ internal sealed class FakeSubscriptionAdapter : ISubscriptionAdapter
     /// <summary>
     ///     Simulates a data change notification for testing.
     /// </summary>
+    /// <param name="handle">The monitored item handle.</param>
+    /// <param name="value">The new data value to simulate.</param>
     public void SimulateDataChange(uint handle, DataValue value)
     {
         (NodeId NodeId, Action<string, DataValue>? DataCallback, Action<EventFieldList>? EventCallback) item;
@@ -129,6 +136,8 @@ internal sealed class FakeSubscriptionAdapter : ISubscriptionAdapter
     /// <summary>
     ///     Simulates an event notification for testing.
     /// </summary>
+    /// <param name="handle">The monitored item handle.</param>
+    /// <param name="eventFields">The event field list to simulate.</param>
     public void SimulateEvent(uint handle, EventFieldList eventFields)
     {
         (NodeId NodeId, Action<string, DataValue>? DataCallback, Action<EventFieldList>? EventCallback) item;

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Helpers/AggregateTypeMapperTests.cs

@@ -8,6 +8,8 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Helpers;
 
 public class AggregateTypeMapperTests
 {
+    /// <summary>Verifies that ToNodeId returns a non-null NodeId for all AggregateType values.</summary>
+    /// <param name="aggregate">The aggregate type to test.</param>
     [Theory]
     [InlineData(AggregateType.Average)]
     [InlineData(AggregateType.Minimum)]
@@ -23,42 +25,49 @@ public class AggregateTypeMapperTests
         nodeId.IsNullNodeId.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that Average aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_Average_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.Average).ShouldBe(ObjectIds.AggregateFunction_Average);
     }
 
+    /// <summary>Verifies that Minimum aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_Minimum_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.Minimum).ShouldBe(ObjectIds.AggregateFunction_Minimum);
     }
 
+    /// <summary>Verifies that Maximum aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_Maximum_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.Maximum).ShouldBe(ObjectIds.AggregateFunction_Maximum);
     }
 
+    /// <summary>Verifies that Count aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_Count_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.Count).ShouldBe(ObjectIds.AggregateFunction_Count);
     }
 
+    /// <summary>Verifies that Start aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_Start_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.Start).ShouldBe(ObjectIds.AggregateFunction_Start);
     }
 
+    /// <summary>Verifies that End aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_End_MapsCorrectly()
     {
         AggregateTypeMapper.ToNodeId(AggregateType.End).ShouldBe(ObjectIds.AggregateFunction_End);
     }
 
+    /// <summary>Verifies that StandardDeviation aggregate type maps to the correct OPC UA node ID.</summary>
     [Fact]
     public void ToNodeId_StandardDeviation_MapsCorrectly()
     {
@@ -66,6 +75,7 @@ public class AggregateTypeMapperTests
             .ShouldBe(ObjectIds.AggregateFunction_StandardDeviationPopulation);
     }
 
+    /// <summary>Verifies that invalid aggregate type value throws ArgumentOutOfRangeException.</summary>
     [Fact]
     public void ToNodeId_InvalidValue_Throws()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Helpers/FailoverUrlParserTests.cs

@@ -6,6 +6,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Helpers;
 
 public class FailoverUrlParserTests
 {
+    /// <summary>Verifies that Parse returns only the primary URL when CSV failover list is null.</summary>
     [Fact]
     public void Parse_CsvNull_ReturnsPrimaryOnly()
     {
@@ -13,6 +14,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns only the primary URL when CSV failover list is empty.</summary>
     [Fact]
     public void Parse_CsvEmpty_ReturnsPrimaryOnly()
     {
@@ -20,6 +22,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns only the primary URL when CSV failover list is whitespace.</summary>
     [Fact]
     public void Parse_CsvWhitespace_ReturnsPrimaryOnly()
     {
@@ -27,6 +30,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns both primary and single failover URL.</summary>
     [Fact]
     public void Parse_SingleFailover_ReturnsBoth()
     {
@@ -34,6 +38,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns primary URL and all failover URLs from CSV list.</summary>
     [Fact]
     public void Parse_MultipleFailovers_ReturnsAll()
     {
@@ -41,6 +46,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup1:4840", "opc.tcp://backup2:4840"]);
     }
 
+    /// <summary>Verifies that Parse trims leading and trailing whitespace from failover URLs.</summary>
     [Fact]
     public void Parse_TrimsWhitespace()
     {
@@ -48,6 +54,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup:4840"]);
     }
 
+    /// <summary>Verifies that Parse deduplicates the primary URL if present in the failover list.</summary>
     [Fact]
     public void Parse_DeduplicatesPrimaryInFailoverList()
     {
@@ -55,6 +62,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup:4840"]);
     }
 
+    /// <summary>Verifies that Parse performs case-insensitive deduplication of URLs.</summary>
     [Fact]
     public void Parse_DeduplicatesCaseInsensitive()
     {
@@ -62,6 +70,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://Primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns only the primary URL when array of failover URLs is null.</summary>
     [Fact]
     public void Parse_ArrayNull_ReturnsPrimaryOnly()
     {
@@ -69,6 +78,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns only the primary URL when array of failover URLs is empty.</summary>
     [Fact]
     public void Parse_ArrayEmpty_ReturnsPrimaryOnly()
     {
@@ -76,6 +86,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840"]);
     }
 
+    /// <summary>Verifies that Parse returns primary URL and all failover URLs from array.</summary>
     [Fact]
     public void Parse_ArrayWithUrls_ReturnsAll()
     {
@@ -84,6 +95,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup1:4840", "opc.tcp://backup2:4840"]);
     }
 
+    /// <summary>Verifies that Parse deduplicates URLs from array if primary URL is present.</summary>
     [Fact]
     public void Parse_ArrayDeduplicates()
     {
@@ -92,6 +104,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup:4840"]);
     }
 
+    /// <summary>Verifies that Parse trims whitespace from URLs in array.</summary>
     [Fact]
     public void Parse_ArrayTrimsWhitespace()
     {
@@ -100,6 +113,7 @@ public class FailoverUrlParserTests
         result.ShouldBe(["opc.tcp://primary:4840", "opc.tcp://backup:4840"]);
     }
 
+    /// <summary>Verifies that Parse skips null and empty URLs from array.</summary>
     [Fact]
     public void Parse_ArraySkipsNullAndEmpty()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Helpers/SecurityModeMapperTests.cs

@@ -8,6 +8,9 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Helpers;
 
 public class SecurityModeMapperTests
 {
+    /// <summary>Verifies ToMessageSecurityMode correctly maps SecurityMode values to OPC UA MessageSecurityMode.</summary>
+    /// <param name="input">The SecurityMode value to map.</param>
+    /// <param name="expected">The expected MessageSecurityMode result.</param>
     [Theory]
     [InlineData(SecurityMode.None, MessageSecurityMode.None)]
     [InlineData(SecurityMode.Sign, MessageSecurityMode.Sign)]
@@ -17,6 +20,7 @@ public class SecurityModeMapperTests
         SecurityModeMapper.ToMessageSecurityMode(input).ShouldBe(expected);
     }
 
+    /// <summary>Verifies ToMessageSecurityMode throws on invalid SecurityMode values.</summary>
     [Fact]
     public void ToMessageSecurityMode_InvalidValue_Throws()
     {
@@ -24,6 +28,9 @@ public class SecurityModeMapperTests
             SecurityModeMapper.ToMessageSecurityMode((SecurityMode)99));
     }
 
+    /// <summary>Verifies FromString correctly parses security mode strings (case-insensitive).</summary>
+    /// <param name="input">The security mode string to parse.</param>
+    /// <param name="expected">The expected SecurityMode result.</param>
     [Theory]
     [InlineData("none", SecurityMode.None)]
     [InlineData("None", SecurityMode.None)]
@@ -38,18 +45,21 @@ public class SecurityModeMapperTests
         SecurityModeMapper.FromString(input).ShouldBe(expected);
     }
 
+    /// <summary>Verifies FromString correctly parses strings with leading and trailing whitespace.</summary>
     [Fact]
     public void FromString_WithWhitespace_ParsesCorrectly()
     {
         SecurityModeMapper.FromString("  sign  ").ShouldBe(SecurityMode.Sign);
     }
 
+    /// <summary>Verifies FromString throws on unrecognized security mode strings.</summary>
     [Fact]
     public void FromString_UnknownValue_Throws()
     {
         Should.Throw<ArgumentException>(() => SecurityModeMapper.FromString("invalid"));
     }
 
+    /// <summary>Verifies FromString returns None when passed a null string.</summary>
     [Fact]
     public void FromString_Null_DefaultsToNone()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Helpers/ValueConverterTests.cs

@@ -6,96 +6,112 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Helpers;
 
 public class ValueConverterTests
 {
+    /// <summary>Verifies that a boolean string "True" is converted to true.</summary>
     [Fact]
     public void ConvertValue_Bool_True()
     {
         ValueConverter.ConvertValue("True", true).ShouldBe(true);
     }
 
+    /// <summary>Verifies that a boolean string "False" is converted to false.</summary>
     [Fact]
     public void ConvertValue_Bool_False()
     {
         ValueConverter.ConvertValue("False", false).ShouldBe(false);
     }
 
+    /// <summary>Verifies that a byte value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Byte()
     {
         ValueConverter.ConvertValue("255", (byte)0).ShouldBe((byte)255);
     }
 
+    /// <summary>Verifies that a short value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Short()
     {
         ValueConverter.ConvertValue("-100", (short)0).ShouldBe((short)-100);
     }
 
+    /// <summary>Verifies that an unsigned short value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_UShort()
     {
         ValueConverter.ConvertValue("65535", (ushort)0).ShouldBe((ushort)65535);
     }
 
+    /// <summary>Verifies that an integer value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Int()
     {
         ValueConverter.ConvertValue("42", 0).ShouldBe(42);
     }
 
+    /// <summary>Verifies that an unsigned integer value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_UInt()
     {
         ValueConverter.ConvertValue("42", 0u).ShouldBe(42u);
     }
 
+    /// <summary>Verifies that a long value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Long()
     {
         ValueConverter.ConvertValue("9999999999", 0L).ShouldBe(9999999999L);
     }
 
+    /// <summary>Verifies that an unsigned long value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_ULong()
     {
         ValueConverter.ConvertValue("18446744073709551615", 0UL).ShouldBe(ulong.MaxValue);
     }
 
+    /// <summary>Verifies that a float value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Float()
     {
         ValueConverter.ConvertValue("3.14", 0f).ShouldBe(3.14f);
     }
 
+    /// <summary>Verifies that a double value is converted correctly.</summary>
     [Fact]
     public void ConvertValue_Double()
     {
         ValueConverter.ConvertValue("3.14159", 0.0).ShouldBe(3.14159);
     }
 
+    /// <summary>Verifies that a string value is converted correctly when the current value is a string.</summary>
     [Fact]
     public void ConvertValue_String_WhenCurrentIsString()
     {
         ValueConverter.ConvertValue("hello", "").ShouldBe("hello");
     }
 
+    /// <summary>Verifies that a string value is converted correctly when the current value is null.</summary>
     [Fact]
     public void ConvertValue_String_WhenCurrentIsNull()
     {
         ValueConverter.ConvertValue("hello", null).ShouldBe("hello");
     }
 
+    /// <summary>Verifies that a string value is converted correctly when the current value is an unknown type.</summary>
     [Fact]
     public void ConvertValue_String_WhenCurrentIsUnknownType()
     {
         ValueConverter.ConvertValue("hello", new object()).ShouldBe("hello");
     }
 
+    /// <summary>Verifies that converting an invalid boolean value throws a FormatException.</summary>
     [Fact]
     public void ConvertValue_InvalidBool_Throws()
     {
         Should.Throw<FormatException>(() => ValueConverter.ConvertValue("notabool", true));
     }
 
+    /// <summary>Verifies that converting an invalid integer value throws a FormatException with a descriptive message.</summary>
     [Fact]
     public void ConvertValue_InvalidInt_ThrowsWithDescription()
     {
@@ -104,6 +120,7 @@ public class ValueConverterTests
         ex.Message.ShouldContain("notanint");
     }
 
+    /// <summary>Verifies that an overflow during conversion throws a FormatException.</summary>
     [Fact]
     public void ConvertValue_Overflow_ThrowsFormatException()
     {
@@ -114,6 +131,9 @@ public class ValueConverterTests
 
     // --- Client.Shared-008: Boolean aliases ---
 
+    /// <summary>Verifies that boolean values accept numeric and word aliases.</summary>
+    /// <param name="input">The input string value.</param>
+    /// <param name="expected">The expected boolean value.</param>
     [Theory]
     [InlineData("1", true)]
     [InlineData("0", false)]
@@ -130,6 +150,7 @@ public class ValueConverterTests
         ValueConverter.ConvertValue(input, true).ShouldBe(expected);
     }
 
+    /// <summary>Verifies that converting an invalid boolean value throws a descriptive FormatException.</summary>
     [Fact]
     public void ConvertValue_InvalidBool_ThrowsDescriptiveFormatException()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Models/ConnectionSettingsTests.cs

@@ -6,6 +6,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Models;
 
 public class ConnectionSettingsTests
 {
+    /// <summary>Verifies that ConnectionSettings defaults are correct.</summary>
     [Fact]
     public void Defaults_AreCorrect()
     {
@@ -24,6 +25,7 @@ public class ConnectionSettingsTests
         settings.CertificateStorePath.ShouldBe(string.Empty);
     }
 
+    /// <summary>Verifies that validation throws on null endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnNullEndpointUrl()
     {
@@ -32,6 +34,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on empty endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnEmptyEndpointUrl()
     {
@@ -40,6 +43,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on whitespace endpoint URL.</summary>
     [Fact]
     public void Validate_ThrowsOnWhitespaceEndpointUrl()
     {
@@ -48,6 +52,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("EndpointUrl");
     }
 
+    /// <summary>Verifies that validation throws on zero timeout.</summary>
     [Fact]
     public void Validate_ThrowsOnZeroTimeout()
     {
@@ -60,6 +65,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation throws on negative timeout.</summary>
     [Fact]
     public void Validate_ThrowsOnNegativeTimeout()
     {
@@ -72,6 +78,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation throws on timeout above 3600 seconds.</summary>
     [Fact]
     public void Validate_ThrowsOnTimeoutAbove3600()
     {
@@ -84,6 +91,7 @@ public class ConnectionSettingsTests
             .ParamName.ShouldBe("SessionTimeoutSeconds");
     }
 
+    /// <summary>Verifies that validation succeeds with valid settings.</summary>
     [Fact]
     public void Validate_SucceedsWithValidSettings()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Models/ModelConstructionTests.cs

@@ -8,6 +8,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Models;
 
 public class ModelConstructionTests
 {
+    /// <summary>Verifies that BrowseResult constructs correctly with all properties.</summary>
     [Fact]
     public void BrowseResult_ConstructsCorrectly()
     {
@@ -19,6 +20,7 @@ public class ModelConstructionTests
         result.HasChildren.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that BrowseResult correctly sets HasChildren to false.</summary>
     [Fact]
     public void BrowseResult_WithoutChildren()
     {
@@ -26,6 +28,7 @@ public class ModelConstructionTests
         result.HasChildren.ShouldBeFalse();
     }
 
+    /// <summary>Verifies that AlarmEventArgs constructs correctly with all properties.</summary>
     [Fact]
     public void AlarmEventArgs_ConstructsCorrectly()
     {
@@ -42,6 +45,7 @@ public class ModelConstructionTests
         args.Time.ShouldBe(time);
     }
 
+    /// <summary>Verifies that RedundancyInfo constructs correctly with all properties.</summary>
     [Fact]
     public void RedundancyInfo_ConstructsCorrectly()
     {
@@ -54,6 +58,7 @@ public class ModelConstructionTests
         info.ApplicationUri.ShouldBe("urn:server1");
     }
 
+    /// <summary>Verifies that RedundancyInfo handles empty URIs correctly.</summary>
     [Fact]
     public void RedundancyInfo_WithEmptyUris()
     {
@@ -62,6 +67,7 @@ public class ModelConstructionTests
         info.ApplicationUri.ShouldBeEmpty();
     }
 
+    /// <summary>Verifies that DataChangedEventArgs constructs correctly with all properties.</summary>
     [Fact]
     public void DataChangedEventArgs_ConstructsCorrectly()
     {
@@ -73,6 +79,7 @@ public class ModelConstructionTests
         args.Value.Value.ShouldBe(42);
     }
 
+    /// <summary>Verifies that ConnectionStateChangedEventArgs constructs correctly with all properties.</summary>
     [Fact]
     public void ConnectionStateChangedEventArgs_ConstructsCorrectly()
     {
@@ -84,6 +91,7 @@ public class ModelConstructionTests
         args.EndpointUrl.ShouldBe("opc.tcp://localhost:4840");
     }
 
+    /// <summary>Verifies that ConnectionInfo constructs correctly with all properties.</summary>
     [Fact]
     public void ConnectionInfo_ConstructsCorrectly()
     {
@@ -103,6 +111,7 @@ public class ModelConstructionTests
         info.SessionName.ShouldBe("TestSession");
     }
 
+    /// <summary>Verifies that SecurityMode enum has the expected number of values.</summary>
     [Fact]
     public void SecurityMode_Enum_HasExpectedValues()
     {
@@ -112,6 +121,7 @@ public class ModelConstructionTests
         ((int)SecurityMode.SignAndEncrypt).ShouldBe(2);
     }
 
+    /// <summary>Verifies that ConnectionState enum has the expected number of values.</summary>
     [Fact]
     public void ConnectionState_Enum_HasExpectedValues()
     {
@@ -122,6 +132,7 @@ public class ModelConstructionTests
         ((int)ConnectionState.Reconnecting).ShouldBe(3);
     }
 
+    /// <summary>Verifies that AggregateType enum has the expected number of values.</summary>
     [Fact]
     public void AggregateType_Enum_HasExpectedValues()
     {

tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/OpcUaClientServiceTests.cs

@@ -16,6 +16,7 @@ public class OpcUaClientServiceTests : IDisposable
     private readonly OpcUaClientService _service;
     private readonly FakeSessionFactory _sessionFactory = new();
 
+    /// <summary>Initializes a new test instance with fake dependencies.</summary>
     public OpcUaClientServiceTests()
     {
         _service = new OpcUaClientService(_configFactory, _endpointDiscovery, _sessionFactory);