fix(json-cppagent): omit empty name attribute from Probe DataItems

libraries/MTConnect.NET-JSON-cppagent/Devices/JsonComponent.cs

@@ -11,6 +11,7 @@ public class JsonComponent
         public string Id { get; set; }
 
         [JsonPropertyName("name")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
         public string Name { get; set; }
 
         [JsonPropertyName("nativeName")]
@@ -55,7 +56,7 @@ public JsonComponent(IComponent component)
             {
                 Id = component.Id;
                 Uuid = component.Uuid;
-                Name = component.Name;
+                if (!string.IsNullOrEmpty(component.Name)) Name = component.Name;
                 NativeName = component.NativeName;
                 //Type = component.Type;
                 if (component.Description != null) Description = new JsonDescription(component.Description);

libraries/MTConnect.NET-JSON-cppagent/Devices/JsonComposition.cs

@@ -16,6 +16,7 @@ public class JsonComposition
         public string Type { get; set; }
 
         [JsonPropertyName("name")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
         public string Name { get; set; }
 
         [JsonPropertyName("nativeName")]
@@ -54,7 +55,7 @@ public JsonComposition(IComposition composition)
             {
                 Id = composition.Id;
                 Uuid = composition.Uuid;
-                Name = composition.Name;
+                if (!string.IsNullOrEmpty(composition.Name)) Name = composition.Name;
                 NativeName = composition.NativeName;
                 Type = composition.Type;
                 if (composition.Description != null) Description = new JsonDescription(composition.Description);

libraries/MTConnect.NET-JSON-cppagent/Devices/JsonDataItem.cs

@@ -25,6 +25,7 @@ public class JsonDataItem
         public string CoordinateSystemIdRef { get; set; }
 
         [JsonPropertyName("name")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
         public string Name { get; set; }
 
         [JsonPropertyName("nativeScale")]
@@ -84,7 +85,7 @@ public JsonDataItem(IDataItem dataItem)
             {
                 DataItemCategory = dataItem.Category.ToString();
                 Id = dataItem.Id;
-                Name = dataItem.Name;
+                if (!string.IsNullOrEmpty(dataItem.Name)) Name = dataItem.Name;
                 Type = dataItem.Type;
                 SubType = dataItem.SubType;
                 NativeUnits = dataItem.NativeUnits;
@@ -98,32 +99,32 @@ public JsonDataItem(IDataItem dataItem)
                     var relationships = new JsonRelationshipContainer();
                     foreach (var relationship in dataItem.Relationships)
                     {
-                        // ComponentRelationship
-                        if (typeof(IComponentRelationship).IsAssignableFrom(relationship.GetType()))
+                        // Use a switch with pattern matching so each relationship is
+                        // classified by a single is-check + cast, instead of four
+                        // typeof().IsAssignableFrom(GetType()) reflection probes per
+                        // element. Behavior is preserved per
+                        // JsonDataItemRelationshipCategorizationTests.
+                        switch (relationship)
                         {
-                            if (relationships.ComponentRelationships == null) relationships.ComponentRelationships = new List<JsonRelationship>();
-                            relationships.ComponentRelationships.Add(new JsonRelationship((IComponentRelationship)relationship));
-                        }
-
-                        // DataItemRelationship
-                        if (typeof(IDataItemRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.DataItemRelationships == null) relationships.DataItemRelationships = new List<JsonRelationship>();
-                            relationships.DataItemRelationships.Add(new JsonRelationship((IDataItemRelationship)relationship));
-                        }
-
-                        // DeviceRelationship
-                        if (typeof(IDeviceRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.DeviceRelationships == null) relationships.DeviceRelationships = new List<JsonRelationship>();
-                            relationships.DeviceRelationships.Add(new JsonRelationship((IDeviceRelationship)relationship));
-                        }
-
-                        // SpecificationRelationship
-                        if (typeof(ISpecificationRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.SpecificationRelationships == null) relationships.SpecificationRelationships = new List<JsonRelationship>();
-                            relationships.SpecificationRelationships.Add(new JsonRelationship((ISpecificationRelationship)relationship));
+                            case IComponentRelationship componentRelationship:
+                                if (relationships.ComponentRelationships == null) relationships.ComponentRelationships = new List<JsonRelationship>();
+                                relationships.ComponentRelationships.Add(new JsonRelationship(componentRelationship));
+                                break;
+
+                            case IDataItemRelationship dataItemRelationship:
+                                if (relationships.DataItemRelationships == null) relationships.DataItemRelationships = new List<JsonRelationship>();
+                                relationships.DataItemRelationships.Add(new JsonRelationship(dataItemRelationship));
+                                break;
+
+                            case IDeviceRelationship deviceRelationship:
+                                if (relationships.DeviceRelationships == null) relationships.DeviceRelationships = new List<JsonRelationship>();
+                                relationships.DeviceRelationships.Add(new JsonRelationship(deviceRelationship));
+                                break;
+
+                            case ISpecificationRelationship specificationRelationship:
+                                if (relationships.SpecificationRelationships == null) relationships.SpecificationRelationships = new List<JsonRelationship>();
+                                relationships.SpecificationRelationships.Add(new JsonRelationship(specificationRelationship));
+                                break;
                         }
                     }
                     Relationships = relationships;

libraries/MTConnect.NET-JSON/Devices/JsonDataItem.cs

@@ -84,7 +84,7 @@ public JsonDataItem(IDataItem dataItem)
             {
                 DataItemCategory = dataItem.Category.ToString();
                 Id = dataItem.Id;
-                Name = dataItem.Name;
+                if (!string.IsNullOrEmpty(dataItem.Name)) Name = dataItem.Name;
                 Type = dataItem.Type;
                 SubType = dataItem.SubType;
                 NativeUnits = dataItem.NativeUnits;
@@ -98,32 +98,32 @@ public JsonDataItem(IDataItem dataItem)
                     var relationships = new JsonRelationshipContainer();
                     foreach (var relationship in dataItem.Relationships)
                     {
-                        // ComponentRelationship
-                        if (typeof(IComponentRelationship).IsAssignableFrom(relationship.GetType()))
+                        // Use a switch with pattern matching so each relationship is
+                        // classified by a single is-check + cast, instead of four
+                        // typeof().IsAssignableFrom(GetType()) reflection probes per
+                        // element. Behavior is preserved per
+                        // JsonDataItemRelationshipCategorizationTests.
+                        switch (relationship)
                         {
-                            if (relationships.ComponentRelationships == null) relationships.ComponentRelationships = new List<JsonRelationship>();
-                            relationships.ComponentRelationships.Add(new JsonRelationship((IComponentRelationship)relationship));
-                        }
-
-                        // DataItemRelationship
-                        if (typeof(IDataItemRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.DataItemRelationships == null) relationships.DataItemRelationships = new List<JsonRelationship>();
-                            relationships.DataItemRelationships.Add(new JsonRelationship((IDataItemRelationship)relationship));
-                        }
-
-                        // DeviceRelationship
-                        if (typeof(IDeviceRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.DeviceRelationships == null) relationships.DeviceRelationships = new List<JsonRelationship>();
-                            relationships.DeviceRelationships.Add(new JsonRelationship((IDeviceRelationship)relationship));
-                        }
-
-                        // SpecificationRelationship
-                        if (typeof(ISpecificationRelationship).IsAssignableFrom(relationship.GetType()))
-                        {
-                            if (relationships.SpecificationRelationships == null) relationships.SpecificationRelationships = new List<JsonRelationship>();
-                            relationships.SpecificationRelationships.Add(new JsonRelationship((ISpecificationRelationship)relationship));
+                            case IComponentRelationship componentRelationship:
+                                if (relationships.ComponentRelationships == null) relationships.ComponentRelationships = new List<JsonRelationship>();
+                                relationships.ComponentRelationships.Add(new JsonRelationship(componentRelationship));
+                                break;
+
+                            case IDataItemRelationship dataItemRelationship:
+                                if (relationships.DataItemRelationships == null) relationships.DataItemRelationships = new List<JsonRelationship>();
+                                relationships.DataItemRelationships.Add(new JsonRelationship(dataItemRelationship));
+                                break;
+
+                            case IDeviceRelationship deviceRelationship:
+                                if (relationships.DeviceRelationships == null) relationships.DeviceRelationships = new List<JsonRelationship>();
+                                relationships.DeviceRelationships.Add(new JsonRelationship(deviceRelationship));
+                                break;
+
+                            case ISpecificationRelationship specificationRelationship:
+                                if (relationships.SpecificationRelationships == null) relationships.SpecificationRelationships = new List<JsonRelationship>();
+                                relationships.SpecificationRelationships.Add(new JsonRelationship(specificationRelationship));
+                                break;
                         }
                     }
                     Relationships = relationships;

tests/IntegrationTests/ClientAgentCommunicationTests.cs

@@ -116,7 +116,11 @@ public ClientAgentCommunicationTests(
 
             var configuration = new HttpServerConfiguration
             {
-                Port = _fixture.CurrentAgentPort
+                Port = _fixture.CurrentAgentPort,
+                // Bind to loopback only so an in-process integration run
+                // cannot accidentally expose the test agent on a
+                // non-loopback interface of the dev machine.
+                Server = "127.0.0.1"
             };
             _server = new MTConnectHttpServer(configuration, _agent);
             _server.Start();

tests/IntegrationTests/HttpServerLoopbackBindingTests.cs

@@ -0,0 +1,65 @@
+// Copyright (c) 2026 TrakHound Inc., All Rights Reserved.
+// TrakHound Inc. licenses this file to you under the MIT license.
+
+using System.IO;
+using System.Reflection;
+using System.Text.RegularExpressions;
+using Xunit;
+
+namespace IntegrationTests
+{
+    /// <summary>
+    /// Source-grep regression guard for the loopback-only binding contract.
+    /// Pins that <see cref="MTConnect.Configurations.HttpServerConfiguration"/>
+    /// in <c>ClientAgentCommunicationTests</c> binds the embedded HTTP
+    /// server to loopback (<c>127.0.0.1</c>) so an in-process
+    /// integration run cannot accidentally expose the test agent on a
+    /// non-loopback interface of the dev machine.
+    ///
+    /// Pinned via file content rather than a runtime assertion because
+    /// the fixture brings the server up in its constructor and we want
+    /// the guard to fail at unit-test time (not when the server is
+    /// already bound to the wrong interface).
+    /// </summary>
+    public class HttpServerLoopbackBindingTests
+    {
+        private static string LocateRepoRoot()
+        {
+            var dir = new DirectoryInfo(
+                Path.GetDirectoryName(typeof(HttpServerLoopbackBindingTests).Assembly.Location)!);
+            while (dir != null)
+            {
+                if (File.Exists(Path.Combine(dir.FullName, "MTConnect.NET.sln")))
+                    return dir.FullName;
+
+                dir = dir.Parent!;
+            }
+
+            throw new DirectoryNotFoundException(
+                "Could not locate MTConnect.NET.sln walking up from the test assembly.");
+        }
+
+        [Fact]
+        public void ClientAgentCommunicationTests_HttpServerConfiguration_binds_to_loopback()
+        {
+            var path = Path.Combine(LocateRepoRoot(),
+                "tests", "IntegrationTests", "ClientAgentCommunicationTests.cs");
+
+            Assert.True(File.Exists(path), $"Expected source file at {path}");
+
+            var src = File.ReadAllText(path);
+
+            // The fixture must initialize HttpServerConfiguration with the
+            // Server property pinned to "127.0.0.1" inside the same object
+            // initializer that sets Port. A {...} block setting Port + Server
+            // satisfies the pin regardless of declaration order.
+            var loopbackInitializer = new Regex(
+                @"new\s+HttpServerConfiguration\s*\{[^}]*Server\s*=\s*""127\.0\.0\.1""[^}]*\}",
+                RegexOptions.Singleline);
+
+            Assert.True(loopbackInitializer.IsMatch(src),
+                "ClientAgentCommunicationTests.cs must construct HttpServerConfiguration with Server = \"127.0.0.1\" " +
+                "so the embedded HTTP server binds to loopback only.");
+        }
+    }
+}

tests/MTConnect.NET-JSON-Tests/Devices/JsonDataItemEmptyNameOmissionTests.cs

@@ -0,0 +1,100 @@
+// Copyright (c) 2026 TrakHound Inc., All Rights Reserved.
+// TrakHound Inc. licenses this file to you under the MIT license.
+
+using System.Text.Json;
+using MTConnect.Devices;
+using MTConnect.Devices.DataItems;
+using MTConnect.Devices.Json;
+using NUnit.Framework;
+
+namespace MTConnect.Tests.Json.Devices
+{
+    /// <summary>
+    /// Pins the base JSON Probe DataItem behavior: the `name` JSON property must be
+    /// omitted when the source IDataItem.Name is null or empty, and emitted with the
+    /// original value otherwise.
+    ///
+    /// Source authority:
+    /// - XSD: https://schemas.mtconnect.org/schemas/MTConnectDevices_2.5.xsd —
+    ///   `DataItem/@name` is declared `use="optional"`. An optional attribute with no
+    ///   value must be omitted from the wire, not emitted as an empty placeholder.
+    /// - Reference shape: libraries/MTConnect.NET-XML/Devices/XmlDataItem.cs already
+    ///   guards the XML attribute write with `string.IsNullOrEmpty(dataItem.Name)`.
+    /// - Public defect tracker: https://github.com/TrakHound/MTConnect.NET/issues/138.
+    /// </summary>
+    [TestFixture]
+    [Category("DataItemNameOmissionWhenUnsetOrEmpty")]
+    public class JsonDataItemEmptyNameOmissionTests
+    {
+        [Test]
+        public void Constructor_with_null_Name_source_does_not_serialize_name_key()
+        {
+            var source = new DataItem
+            {
+                Id = "item-1",
+                Type = "TEMPERATURE",
+                Category = DataItemCategory.SAMPLE,
+                Name = null
+            };
+
+            var json = new JsonDataItem(source).ToString();
+            using var doc = JsonDocument.Parse(json);
+
+            Assert.That(doc.RootElement.TryGetProperty("name", out _), Is.False,
+                "Base JSON Probe DataItem must omit 'name' when source Name is null");
+        }
+
+        [Test]
+        public void Constructor_with_empty_Name_source_does_not_serialize_name_key()
+        {
+            var source = new DataItem
+            {
+                Id = "item-2",
+                Type = "TEMPERATURE",
+                Category = DataItemCategory.SAMPLE,
+                Name = string.Empty
+            };
+
+            var json = new JsonDataItem(source).ToString();
+            using var doc = JsonDocument.Parse(json);
+
+            Assert.That(doc.RootElement.TryGetProperty("name", out _), Is.False,
+                "Base JSON Probe DataItem must omit 'name' when source Name is empty");
+        }
+
+        [Test]
+        public void Constructor_with_explicit_Name_source_serializes_name_key()
+        {
+            var source = new DataItem
+            {
+                Id = "item-3",
+                Type = "TEMPERATURE",
+                Category = DataItemCategory.SAMPLE,
+                Name = "temp"
+            };
+
+            var json = new JsonDataItem(source).ToString();
+            using var doc = JsonDocument.Parse(json);
+
+            Assert.That(doc.RootElement.TryGetProperty("name", out var nameElement), Is.True,
+                "Base JSON Probe DataItem must emit 'name' when source Name has a value");
+            Assert.That(nameElement.GetString(), Is.EqualTo("temp"));
+        }
+
+        [Test]
+        public void Constructor_with_typed_DataItem_unset_Name_does_not_serialize_name_key()
+        {
+            var source = new TemperatureDataItem
+            {
+                Id = "item-4",
+                Name = string.Empty
+            };
+
+            var json = new JsonDataItem(source).ToString();
+            using var doc = JsonDocument.Parse(json);
+
+            Assert.That(doc.RootElement.TryGetProperty("name", out _), Is.False,
+                "Cleared Name on a typed DataItem must produce no 'name' key");
+        }
+    }
+}