feat(client-cli): add ack/confirm/shelve alarm commands with service layer

Adds ConfirmAlarmAsync and ShelveAlarmAsync to IOpcUaClientService and
OpcUaClientService (mirroring the AcknowledgeAlarmAsync pattern: same
CallMethodAsync/ServiceResultException/StatusCode contract). Adds ShelveKind
enum (OneShot/Timed/Unshelve). Adds three new CLI commands — ack, confirm,
shelve — with hex EventId input and per-command argument validation.
Updates both fakes (CLI + UI) to implement the new interface members and
record calls. Adds 16 unit tests covering argument mapping, invalid-input
CommandException paths, bad-status output, and disconnect-in-finally.

src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI/Commands/AcknowledgeCommand.cs

@@ -0,0 +1,78 @@
+using CliFx.Attributes;
+using CliFx.Exceptions;
+using CliFx.Infrastructure;
+using Opc.Ua;
+using ZB.MOM.WW.OtOpcUa.Client.Shared;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+
+[Command("ack", Description = "Acknowledge an active alarm condition (OPC UA Part 9)")]
+public class AcknowledgeCommand : CommandBase
+{
+    /// <summary>
+    /// Creates the acknowledge command used to acknowledge an active OPC UA condition from the terminal.
+    /// </summary>
+    /// <param name="factory">The factory that creates the shared client service for the command run.</param>
+    public AcknowledgeCommand(IOpcUaClientServiceFactory factory) : base(factory)
+    {
+    }
+
+    /// <summary>
+    /// Gets the condition node ID of the alarm event to acknowledge.
+    /// </summary>
+    [CommandOption("node", 'n', Description = "Condition node ID of the alarm to acknowledge", IsRequired = true)]
+    public string NodeId { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the event ID (hex-encoded) returned by the server in the alarm notification.
+    /// </summary>
+    [CommandOption("event-id", 'e', Description = "EventId from the alarm notification (hex-encoded byte array)", IsRequired = true)]
+    public string EventId { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the operator comment to include with the acknowledgment.
+    /// </summary>
+    [CommandOption("comment", 'c', Description = "Operator comment for the acknowledgment")]
+    public string Comment { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Connects to the server and acknowledges the specified alarm condition.
+    /// </summary>
+    /// <param name="console">The CLI console used for output and cancellation handling.</param>
+    public override async ValueTask ExecuteAsync(IConsole console)
+    {
+        ConfigureLogging();
+
+        byte[] eventId;
+        try
+        {
+            eventId = Convert.FromHexString(EventId);
+        }
+        catch (FormatException ex)
+        {
+            throw new CommandException($"Invalid --event-id value: {ex.Message} (expected hex-encoded bytes, e.g. 0A1B2C)");
+        }
+
+        IOpcUaClientService? service = null;
+        try
+        {
+            var ct = console.RegisterCancellationHandler();
+            (service, _) = await CreateServiceAndConnectAsync(ct);
+
+            var statusCode = await service.AcknowledgeAlarmAsync(NodeId, eventId, Comment, ct);
+
+            if (StatusCode.IsGood(statusCode))
+                await console.Output.WriteLineAsync($"Acknowledge successful: {NodeId}");
+            else
+                await console.Output.WriteLineAsync($"Acknowledge failed: {statusCode}");
+        }
+        finally
+        {
+            if (service != null)
+            {
+                await service.DisconnectAsync();
+                service.Dispose();
+            }
+        }
+    }
+}

src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI/Commands/ConfirmCommand.cs

@@ -0,0 +1,78 @@
+using CliFx.Attributes;
+using CliFx.Exceptions;
+using CliFx.Infrastructure;
+using Opc.Ua;
+using ZB.MOM.WW.OtOpcUa.Client.Shared;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+
+[Command("confirm", Description = "Confirm an acknowledged alarm condition (OPC UA Part 9 two-stage acknowledgment)")]
+public class ConfirmCommand : CommandBase
+{
+    /// <summary>
+    /// Creates the confirm command used to confirm an acknowledged OPC UA condition from the terminal.
+    /// </summary>
+    /// <param name="factory">The factory that creates the shared client service for the command run.</param>
+    public ConfirmCommand(IOpcUaClientServiceFactory factory) : base(factory)
+    {
+    }
+
+    /// <summary>
+    /// Gets the condition node ID of the alarm event to confirm.
+    /// </summary>
+    [CommandOption("node", 'n', Description = "Condition node ID of the alarm to confirm", IsRequired = true)]
+    public string NodeId { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the event ID (hex-encoded) returned by the server in the alarm notification.
+    /// </summary>
+    [CommandOption("event-id", 'e', Description = "EventId from the alarm notification (hex-encoded byte array)", IsRequired = true)]
+    public string EventId { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the operator comment to include with the confirmation.
+    /// </summary>
+    [CommandOption("comment", 'c', Description = "Operator comment for the confirmation")]
+    public string Comment { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Connects to the server and confirms the specified acknowledged alarm condition.
+    /// </summary>
+    /// <param name="console">The CLI console used for output and cancellation handling.</param>
+    public override async ValueTask ExecuteAsync(IConsole console)
+    {
+        ConfigureLogging();
+
+        byte[] eventId;
+        try
+        {
+            eventId = Convert.FromHexString(EventId);
+        }
+        catch (FormatException ex)
+        {
+            throw new CommandException($"Invalid --event-id value: {ex.Message} (expected hex-encoded bytes, e.g. 0A1B2C)");
+        }
+
+        IOpcUaClientService? service = null;
+        try
+        {
+            var ct = console.RegisterCancellationHandler();
+            (service, _) = await CreateServiceAndConnectAsync(ct);
+
+            var statusCode = await service.ConfirmAlarmAsync(NodeId, eventId, Comment, ct);
+
+            if (StatusCode.IsGood(statusCode))
+                await console.Output.WriteLineAsync($"Confirm successful: {NodeId}");
+            else
+                await console.Output.WriteLineAsync($"Confirm failed: {statusCode}");
+        }
+        finally
+        {
+            if (service != null)
+            {
+                await service.DisconnectAsync();
+                service.Dispose();
+            }
+        }
+    }
+}

src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI/Commands/ShelveCommand.cs

@@ -0,0 +1,77 @@
+using CliFx.Attributes;
+using CliFx.Exceptions;
+using CliFx.Infrastructure;
+using Opc.Ua;
+using ZB.MOM.WW.OtOpcUa.Client.Shared;
+using ZB.MOM.WW.OtOpcUa.Client.Shared.Models;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+
+[Command("shelve", Description = "Shelve or unshelve an active alarm condition (OPC UA Part 9 ShelvedStateMachine)")]
+public class ShelveCommand : CommandBase
+{
+    /// <summary>
+    /// Creates the shelve command used to shelve or unshelve an OPC UA alarm condition from the terminal.
+    /// </summary>
+    /// <param name="factory">The factory that creates the shared client service for the command run.</param>
+    public ShelveCommand(IOpcUaClientServiceFactory factory) : base(factory)
+    {
+    }
+
+    /// <summary>
+    /// Gets the condition node ID of the alarm to shelve or unshelve.
+    /// </summary>
+    [CommandOption("node", 'n', Description = "Condition node ID of the alarm to shelve/unshelve", IsRequired = true)]
+    public string NodeId { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the shelve operation kind: OneShot, Timed, or Unshelve.
+    /// </summary>
+    [CommandOption("kind", 'k', Description = "Shelve operation: OneShot | Timed | Unshelve", IsRequired = true)]
+    public string Kind { get; init; } = default!;
+
+    /// <summary>
+    /// Gets the shelving duration in seconds for Timed shelving (ignored for OneShot and Unshelve).
+    /// </summary>
+    [CommandOption("duration", 'd', Description = "Shelving duration in seconds (required for --kind Timed)")]
+    public double DurationSeconds { get; init; }
+
+    /// <summary>
+    /// Connects to the server and shelves or unshelves the specified alarm condition.
+    /// </summary>
+    /// <param name="console">The CLI console used for output and cancellation handling.</param>
+    public override async ValueTask ExecuteAsync(IConsole console)
+    {
+        ConfigureLogging();
+
+        if (!Enum.TryParse<ShelveKind>(Kind, ignoreCase: true, out var shelveKind))
+            throw new CommandException(
+                $"Invalid --kind value '{Kind}'. Expected one of: OneShot, Timed, Unshelve.");
+
+        if (shelveKind == ShelveKind.Timed && DurationSeconds <= 0)
+            throw new CommandException(
+                "--duration must be greater than 0 when --kind is Timed.");
+
+        IOpcUaClientService? service = null;
+        try
+        {
+            var ct = console.RegisterCancellationHandler();
+            (service, _) = await CreateServiceAndConnectAsync(ct);
+
+            var statusCode = await service.ShelveAlarmAsync(NodeId, shelveKind, DurationSeconds, ct);
+
+            if (StatusCode.IsGood(statusCode))
+                await console.Output.WriteLineAsync($"Shelve ({shelveKind}) successful: {NodeId}");
+            else
+                await console.Output.WriteLineAsync($"Shelve ({shelveKind}) failed: {statusCode}");
+        }
+        finally
+        {
+            if (service != null)
+            {
+                await service.DisconnectAsync();
+                service.Dispose();
+            }
+        }
+    }
+}

src/Client/ZB.MOM.WW.OtOpcUa.Client.Shared/IOpcUaClientService.cs

@@ -103,6 +103,36 @@ public interface IOpcUaClientService : IDisposable
     /// </returns>
     Task<StatusCode> AcknowledgeAlarmAsync(string conditionNodeId, byte[] eventId, string comment, CancellationToken ct = default);
 
+    /// <summary>
+    /// Confirms an acknowledged condition (Part 9 two-stage acknowledgment) using the event identifier returned by an alarm notification.
+    /// </summary>
+    /// <param name="conditionNodeId">The condition node associated with the alarm event being confirmed.</param>
+    /// <param name="eventId">The event identifier returned by the OPC UA server for the alarm event.</param>
+    /// <param name="comment">The operator confirmation comment to write with the method call.</param>
+    /// <param name="ct">The cancellation token that aborts the confirmation request.</param>
+    /// <returns>
+    /// <see cref="StatusCodes.Good"/> on success, or the server's bad <see cref="StatusCode"/>
+    /// (from the underlying <see cref="ServiceResultException"/>) when the confirm call
+    /// returns a bad result. Other transport-level failures still surface as exceptions.
+    /// </returns>
+    Task<StatusCode> ConfirmAlarmAsync(string conditionNodeId, byte[] eventId, string comment, CancellationToken ct = default);
+
+    /// <summary>
+    /// Shelves or unshelves an active alarm condition (OPC UA Part 9 ShelvedStateMachine).
+    /// </summary>
+    /// <param name="conditionNodeId">The condition node associated with the alarm being shelved.</param>
+    /// <param name="kind">The shelve operation: <c>OneShot</c>, <c>Timed</c>, or <c>Unshelve</c>.</param>
+    /// <param name="shelvingTimeSeconds">
+    /// For <c>Timed</c> shelving: the shelving duration in seconds. Ignored for <c>OneShot</c> and <c>Unshelve</c>.
+    /// </param>
+    /// <param name="ct">The cancellation token that aborts the shelve request.</param>
+    /// <returns>
+    /// <see cref="StatusCodes.Good"/> on success, or the server's bad <see cref="StatusCode"/>
+    /// (from the underlying <see cref="ServiceResultException"/>) when the shelve call
+    /// returns a bad result. Other transport-level failures still surface as exceptions.
+    /// </returns>
+    Task<StatusCode> ShelveAlarmAsync(string conditionNodeId, ShelveKind kind, double shelvingTimeSeconds = 0, CancellationToken ct = default);
+
     /// <summary>
     /// Reads raw historical samples for a historized node.
     /// </summary>

src/Client/ZB.MOM.WW.OtOpcUa.Client.Shared/Models/ShelveKind.cs

@@ -0,0 +1,25 @@
+namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Models;
+
+/// <summary>
+///     Shelve operations supported by the OPC UA Part 9 ShelvedStateMachine.
+/// </summary>
+public enum ShelveKind
+{
+    /// <summary>
+    /// OneShotShelve: suppresses the alarm for one occurrence. The alarm automatically
+    /// unshelves when it next returns to the inactive state.
+    /// </summary>
+    OneShot,
+
+    /// <summary>
+    /// TimedShelve: suppresses the alarm for a specified duration (seconds).
+    /// Requires a positive <c>shelvingTimeSeconds</c> argument.
+    /// </summary>
+    Timed,
+
+    /// <summary>
+    /// Unshelve: removes an active OneShotShelve or TimedShelve, returning the alarm
+    /// to its normal active-notification state.
+    /// </summary>
+    Unshelve
+}

src/Client/ZB.MOM.WW.OtOpcUa.Client.Shared/OpcUaClientService.cs

@@ -376,6 +376,88 @@ public sealed class OpcUaClientService : IOpcUaClientService
         return StatusCodes.Good;
     }
 
+    /// <inheritdoc />
+    public async Task<StatusCode> ConfirmAlarmAsync(string conditionNodeId, byte[] eventId, string comment,
+        CancellationToken ct = default)
+    {
+        ThrowIfDisposed();
+        ThrowIfNotConnected();
+
+        // Confirm lives on the same .Condition child node as Acknowledge
+        var conditionObjId = conditionNodeId.EndsWith(".Condition")
+            ? NodeId.Parse(conditionNodeId)
+            : NodeId.Parse(conditionNodeId + ".Condition");
+        var confirmMethodId = MethodIds.AcknowledgeableConditionType_Confirm;
+
+        try
+        {
+            await _session!.CallMethodAsync(
+                conditionObjId,
+                confirmMethodId,
+                [eventId, new LocalizedText(comment)],
+                ct);
+        }
+        catch (ServiceResultException ex)
+        {
+            Logger.Warning(ex, "Failed to confirm alarm on {ConditionId} (status {Status})",
+                conditionNodeId, ex.StatusCode);
+            return ex.StatusCode;
+        }
+
+        Logger.Debug("Confirmed alarm on {ConditionId}", conditionNodeId);
+        return StatusCodes.Good;
+    }
+
+    /// <inheritdoc />
+    public async Task<StatusCode> ShelveAlarmAsync(string conditionNodeId, ShelveKind kind,
+        double shelvingTimeSeconds = 0, CancellationToken ct = default)
+    {
+        ThrowIfDisposed();
+        ThrowIfNotConnected();
+
+        // The shelve methods live on the ShelvingState child of the condition node.
+        // conditionNodeId is the alarm/condition node; append .ShelvingState to get the state machine node.
+        var shelvingStateNodeId = NodeId.Parse(conditionNodeId + ".ShelvingState");
+
+        NodeId methodId;
+        object[] inputArgs;
+
+        switch (kind)
+        {
+            case ShelveKind.OneShot:
+                methodId = MethodIds.AlarmConditionType_ShelvingState_OneShotShelve;
+                inputArgs = [];
+                break;
+            case ShelveKind.Timed:
+                if (shelvingTimeSeconds <= 0)
+                    throw new ArgumentOutOfRangeException(nameof(shelvingTimeSeconds),
+                        "Timed shelving requires a positive shelvingTimeSeconds value.");
+                methodId = MethodIds.AlarmConditionType_ShelvingState_TimedShelve;
+                inputArgs = [shelvingTimeSeconds];
+                break;
+            case ShelveKind.Unshelve:
+                methodId = MethodIds.AlarmConditionType_ShelvingState_Unshelve;
+                inputArgs = [];
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(kind), kind, "Unknown ShelveKind value.");
+        }
+
+        try
+        {
+            await _session!.CallMethodAsync(shelvingStateNodeId, methodId, inputArgs, ct);
+        }
+        catch (ServiceResultException ex)
+        {
+            Logger.Warning(ex, "Failed to shelve alarm on {ConditionId} kind={Kind} (status {Status})",
+                conditionNodeId, kind, ex.StatusCode);
+            return ex.StatusCode;
+        }
+
+        Logger.Debug("Shelved alarm on {ConditionId} kind={Kind}", conditionNodeId, kind);
+        return StatusCodes.Good;
+    }
+
     /// <inheritdoc />
     public async Task<IReadOnlyList<DataValue>> HistoryReadRawAsync(
         NodeId nodeId, DateTime startTime, DateTime endTime, int maxValues = 1000, CancellationToken ct = default)

tests/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/AcknowledgeCommandTests.cs

@@ -0,0 +1,106 @@
+using CliFx.Exceptions;
+using Opc.Ua;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Tests.Fakes;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
+
+public class AcknowledgeCommandTests
+{
+    private static string HexOf(byte[] bytes) => Convert.ToHexString(bytes);
+
+    /// <summary>Verifies that a successful ack prints a success message.</summary>
+    [Fact]
+    public async Task Execute_Success_PrintsSuccessMessage()
+    {
+        var fakeService = new FakeOpcUaClientService
+        {
+            AcknowledgeAlarmResult = StatusCodes.Good
+        };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var eventId = new byte[] { 0x01, 0x02, 0x03 };
+        var command = new AcknowledgeCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(eventId),
+            Comment = "test comment"
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("Acknowledge successful");
+        fakeService.AcknowledgeAlarmCalls.Count.ShouldBe(1);
+        fakeService.AcknowledgeAlarmCalls[0].ConditionNodeId.ShouldBe("ns=2;s=MyAlarm");
+        fakeService.AcknowledgeAlarmCalls[0].EventId.ShouldBe(eventId);
+        fakeService.AcknowledgeAlarmCalls[0].Comment.ShouldBe("test comment");
+    }
+
+    /// <summary>Verifies that a bad StatusCode from the service prints a failure message.</summary>
+    [Fact]
+    public async Task Execute_BadStatus_PrintsFailureMessage()
+    {
+        var fakeService = new FakeOpcUaClientService
+        {
+            AcknowledgeAlarmResult = StatusCodes.BadEventNotAcknowledgeable
+        };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new AcknowledgeCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(new byte[] { 0xAB }),
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("Acknowledge failed");
+    }
+
+    /// <summary>Verifies that an invalid hex event-id throws CommandException.</summary>
+    [Fact]
+    public async Task Execute_InvalidEventId_ThrowsCommandException()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new AcknowledgeCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = "not-hex!",
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        var ex = await Should.ThrowAsync<CommandException>(async () => await command.ExecuteAsync(console));
+        ex.Message.ShouldContain("event-id", Case.Insensitive);
+    }
+
+    /// <summary>Verifies that the command disconnects in the finally block.</summary>
+    [Fact]
+    public async Task Execute_DisconnectsInFinally()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new AcknowledgeCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(new byte[] { 0x01 }),
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.DisconnectCalled.ShouldBeTrue();
+        fakeService.DisposeCalled.ShouldBeTrue();
+    }
+}

tests/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/ConfirmCommandTests.cs

@@ -0,0 +1,106 @@
+using CliFx.Exceptions;
+using Opc.Ua;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Tests.Fakes;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
+
+public class ConfirmCommandTests
+{
+    private static string HexOf(byte[] bytes) => Convert.ToHexString(bytes);
+
+    /// <summary>Verifies that a successful confirm prints a success message and passes correct arguments to the service.</summary>
+    [Fact]
+    public async Task Execute_Success_PrintsSuccessMessage()
+    {
+        var fakeService = new FakeOpcUaClientService
+        {
+            ConfirmAlarmResult = StatusCodes.Good
+        };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var eventId = new byte[] { 0x0A, 0x1B, 0x2C };
+        var command = new ConfirmCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(eventId),
+            Comment = "confirmed by operator"
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("Confirm successful");
+        fakeService.ConfirmAlarmCalls.Count.ShouldBe(1);
+        fakeService.ConfirmAlarmCalls[0].ConditionNodeId.ShouldBe("ns=2;s=MyAlarm");
+        fakeService.ConfirmAlarmCalls[0].EventId.ShouldBe(eventId);
+        fakeService.ConfirmAlarmCalls[0].Comment.ShouldBe("confirmed by operator");
+    }
+
+    /// <summary>Verifies that a bad StatusCode from the service prints a failure message.</summary>
+    [Fact]
+    public async Task Execute_BadStatus_PrintsFailureMessage()
+    {
+        var fakeService = new FakeOpcUaClientService
+        {
+            ConfirmAlarmResult = StatusCodes.BadConditionBranchAlreadyConfirmed
+        };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ConfirmCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(new byte[] { 0xFF }),
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("Confirm failed");
+    }
+
+    /// <summary>Verifies that an invalid hex event-id throws CommandException.</summary>
+    [Fact]
+    public async Task Execute_InvalidEventId_ThrowsCommandException()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ConfirmCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = "ZZZ-not-hex",
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        var ex = await Should.ThrowAsync<CommandException>(async () => await command.ExecuteAsync(console));
+        ex.Message.ShouldContain("event-id", Case.Insensitive);
+    }
+
+    /// <summary>Verifies that the command disconnects in the finally block.</summary>
+    [Fact]
+    public async Task Execute_DisconnectsInFinally()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ConfirmCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            EventId = HexOf(new byte[] { 0x01 }),
+            Comment = ""
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.DisconnectCalled.ShouldBeTrue();
+        fakeService.DisposeCalled.ShouldBeTrue();
+    }
+}

tests/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/Fakes/FakeOpcUaClientService.cs

@@ -220,11 +220,46 @@ public sealed class FakeOpcUaClientService : IOpcUaClientService
         return Task.CompletedTask;
     }
 
+    /// <summary>Gets the list of (conditionNodeId, eventId, comment) tuples from AcknowledgeAlarmAsync calls.</summary>
+    public List<(string ConditionNodeId, byte[] EventId, string Comment)> AcknowledgeAlarmCalls { get; } = [];
+
+    /// <summary>Gets or sets the status code returned by AcknowledgeAlarmAsync.</summary>
+    public StatusCode AcknowledgeAlarmResult { get; set; } = StatusCodes.Good;
+
     /// <inheritdoc />
     public Task<StatusCode> AcknowledgeAlarmAsync(string conditionNodeId, byte[] eventId, string comment,
         CancellationToken ct = default)
     {
-        return Task.FromResult(new StatusCode(StatusCodes.Good));
+        AcknowledgeAlarmCalls.Add((conditionNodeId, eventId, comment));
+        return Task.FromResult(AcknowledgeAlarmResult);
+    }
+
+    /// <summary>Gets the list of (conditionNodeId, eventId, comment) tuples from ConfirmAlarmAsync calls.</summary>
+    public List<(string ConditionNodeId, byte[] EventId, string Comment)> ConfirmAlarmCalls { get; } = [];
+
+    /// <summary>Gets or sets the status code returned by ConfirmAlarmAsync.</summary>
+    public StatusCode ConfirmAlarmResult { get; set; } = StatusCodes.Good;
+
+    /// <inheritdoc />
+    public Task<StatusCode> ConfirmAlarmAsync(string conditionNodeId, byte[] eventId, string comment,
+        CancellationToken ct = default)
+    {
+        ConfirmAlarmCalls.Add((conditionNodeId, eventId, comment));
+        return Task.FromResult(ConfirmAlarmResult);
+    }
+
+    /// <summary>Gets the list of (conditionNodeId, kind, durationSeconds) tuples from ShelveAlarmAsync calls.</summary>
+    public List<(string ConditionNodeId, ShelveKind Kind, double DurationSeconds)> ShelveAlarmCalls { get; } = [];
+
+    /// <summary>Gets or sets the status code returned by ShelveAlarmAsync.</summary>
+    public StatusCode ShelveAlarmResult { get; set; } = StatusCodes.Good;
+
+    /// <inheritdoc />
+    public Task<StatusCode> ShelveAlarmAsync(string conditionNodeId, ShelveKind kind, double shelvingTimeSeconds = 0,
+        CancellationToken ct = default)
+    {
+        ShelveAlarmCalls.Add((conditionNodeId, kind, shelvingTimeSeconds));
+        return Task.FromResult(ShelveAlarmResult);
     }
 
     /// <inheritdoc />

tests/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/ShelveCommandTests.cs

@@ -0,0 +1,181 @@
+using CliFx.Exceptions;
+using Opc.Ua;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Commands;
+using ZB.MOM.WW.OtOpcUa.Client.CLI.Tests.Fakes;
+using ZB.MOM.WW.OtOpcUa.Client.Shared.Models;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
+
+public class ShelveCommandTests
+{
+    /// <summary>Verifies that OneShot shelving produces the correct kind and zero duration.</summary>
+    [Fact]
+    public async Task Execute_OneShotKind_PassesOneShotToService()
+    {
+        var fakeService = new FakeOpcUaClientService { ShelveAlarmResult = StatusCodes.Good };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "OneShot",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.ShelveAlarmCalls.Count.ShouldBe(1);
+        fakeService.ShelveAlarmCalls[0].Kind.ShouldBe(ShelveKind.OneShot);
+        fakeService.ShelveAlarmCalls[0].DurationSeconds.ShouldBe(0);
+        fakeService.ShelveAlarmCalls[0].ConditionNodeId.ShouldBe("ns=2;s=MyAlarm");
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("successful");
+    }
+
+    /// <summary>Verifies that Timed shelving passes the correct duration to the service.</summary>
+    [Fact]
+    public async Task Execute_TimedKind_PassesDurationToService()
+    {
+        var fakeService = new FakeOpcUaClientService { ShelveAlarmResult = StatusCodes.Good };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "Timed",
+            DurationSeconds = 300
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.ShelveAlarmCalls.Count.ShouldBe(1);
+        fakeService.ShelveAlarmCalls[0].Kind.ShouldBe(ShelveKind.Timed);
+        fakeService.ShelveAlarmCalls[0].DurationSeconds.ShouldBe(300);
+    }
+
+    /// <summary>Verifies that Unshelve produces the Unshelve kind.</summary>
+    [Fact]
+    public async Task Execute_UnshelveKind_PassesUnshelveToService()
+    {
+        var fakeService = new FakeOpcUaClientService { ShelveAlarmResult = StatusCodes.Good };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "Unshelve",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.ShelveAlarmCalls.Count.ShouldBe(1);
+        fakeService.ShelveAlarmCalls[0].Kind.ShouldBe(ShelveKind.Unshelve);
+    }
+
+    /// <summary>Verifies that kind parsing is case-insensitive (e.g. "oneshot" works).</summary>
+    [Fact]
+    public async Task Execute_KindCaseInsensitive_ParsesCorrectly()
+    {
+        var fakeService = new FakeOpcUaClientService { ShelveAlarmResult = StatusCodes.Good };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "oneshot",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.ShelveAlarmCalls.Count.ShouldBe(1);
+        fakeService.ShelveAlarmCalls[0].Kind.ShouldBe(ShelveKind.OneShot);
+    }
+
+    /// <summary>Verifies that an invalid Kind value throws CommandException.</summary>
+    [Fact]
+    public async Task Execute_InvalidKind_ThrowsCommandException()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "SuperShelve",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        var ex = await Should.ThrowAsync<CommandException>(async () => await command.ExecuteAsync(console));
+        ex.Message.ShouldContain("kind", Case.Insensitive);
+    }
+
+    /// <summary>Verifies that Timed with zero duration throws CommandException (missing --duration).</summary>
+    [Fact]
+    public async Task Execute_TimedWithZeroDuration_ThrowsCommandException()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "Timed",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        var ex = await Should.ThrowAsync<CommandException>(async () => await command.ExecuteAsync(console));
+        ex.Message.ShouldContain("duration", Case.Insensitive);
+    }
+
+    /// <summary>Verifies that a bad status code from the service prints a failure message.</summary>
+    [Fact]
+    public async Task Execute_BadStatus_PrintsFailureMessage()
+    {
+        var fakeService = new FakeOpcUaClientService { ShelveAlarmResult = StatusCodes.BadNotSupported };
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "OneShot",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        var output = TestConsoleHelper.GetOutput(console);
+        output.ShouldContain("failed");
+    }
+
+    /// <summary>Verifies that the command disconnects in the finally block.</summary>
+    [Fact]
+    public async Task Execute_DisconnectsInFinally()
+    {
+        var fakeService = new FakeOpcUaClientService();
+        var factory = new FakeOpcUaClientServiceFactory(fakeService);
+        var command = new ShelveCommand(factory)
+        {
+            Url = "opc.tcp://localhost:4840",
+            NodeId = "ns=2;s=MyAlarm",
+            Kind = "OneShot",
+            DurationSeconds = 0
+        };
+
+        using var console = TestConsoleHelper.CreateConsole();
+        await command.ExecuteAsync(console);
+
+        fakeService.DisconnectCalled.ShouldBeTrue();
+        fakeService.DisposeCalled.ShouldBeTrue();
+    }
+}

tests/Client/ZB.MOM.WW.OtOpcUa.Client.UI.Tests/Fakes/FakeOpcUaClientService.cs

@@ -263,6 +263,26 @@ public sealed class FakeOpcUaClientService : IOpcUaClientService
         return Task.FromResult(AcknowledgeResult);
     }
 
+    /// <summary>Gets or sets the status code returned by confirmation operations in UI tests.</summary>
+    public StatusCode ConfirmResult { get; set; } = StatusCodes.Good;
+
+    /// <inheritdoc />
+    public Task<StatusCode> ConfirmAlarmAsync(string conditionNodeId, byte[] eventId, string comment,
+        CancellationToken ct = default)
+    {
+        return Task.FromResult(ConfirmResult);
+    }
+
+    /// <summary>Gets or sets the status code returned by shelve operations in UI tests.</summary>
+    public StatusCode ShelveResult { get; set; } = StatusCodes.Good;
+
+    /// <inheritdoc />
+    public Task<StatusCode> ShelveAlarmAsync(string conditionNodeId, ShelveKind kind, double shelvingTimeSeconds = 0,
+        CancellationToken ct = default)
+    {
+        return Task.FromResult(ShelveResult);
+    }
+
     /// <inheritdoc />
     public Task<IReadOnlyList<DataValue>> HistoryReadRawAsync(NodeId nodeId, DateTime startTime, DateTime endTime,
         int maxValues = 1000, CancellationToken ct = default)