Skip empty client generation

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/src/Providers/ClientProvider.cs

@@ -229,7 +229,7 @@ protected override FieldProvider[] BuildFields()
             // add sub-client caching fields
             foreach (var subClient in SubClients)
             {
-                if (subClient.Value._clientCachingField != null)
+                if (subClient.Value.Methods.Count != 0 && subClient.Value._clientCachingField != null)
                 {
                     fields.Add(subClient.Value._clientCachingField);
                 }
@@ -479,7 +479,7 @@ protected override MethodProvider[] BuildMethods()
             foreach (var subClient in SubClients)
             {
                 var subClientInstance = subClient.Value;
-                if (subClientInstance._clientCachingField is null)
+                if (subClientInstance._clientCachingField is null || subClientInstance.Methods.Count == 0)
                 {
                     continue;
                 }

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/src/ScmOutputLibrary.cs

@@ -16,6 +16,10 @@ private static TypeProvider[] BuildClients()
             foreach (var inputClient in inputClients)
             {
                 var client = ClientModelPlugin.Instance.TypeFactory.CreateClient(inputClient);
+                if (client.Methods.Count == 0)
+                {
+                    continue;
+                }
                 clients.Add(client);
                 clients.Add(client.RestClient);
                 var clientOptions = client.ClientOptions;

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/ClientProviders/ClientProviderCustomizationTests.cs

@@ -275,7 +275,7 @@ public async Task CanRenameSubClient()
                 InputFactory.Parameter("p1", InputFactory.Array(InputPrimitiveType.String))
             ]);
             var inputClient = InputFactory.Client("TestClient", operations: [inputOperation]);
-            InputClient subClient = InputFactory.Client("custom", [], [], inputClient.Name);
+            InputClient subClient = InputFactory.Client("custom", [inputOperation], [], inputClient.Name);
             var plugin = await MockHelpers.LoadMockPluginAsync(
                 clients: () => [inputClient, subClient],
                 compilation: async () => await Helpers.GetCompilationFromDirectoryAsync());

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/ClientProviders/ClientProviderSubClientTests.cs

@@ -14,11 +14,15 @@ namespace Microsoft.Generator.CSharp.ClientModel.Tests.Providers.ClientProviders
     public class ClientProviderSubClientTests
     {
         private const string TestClientName = "TestClient";
-        private static readonly InputClient _animalClient = new("animal", string.Empty, "AnimalClient description", [], [], TestClientName);
-        private static readonly InputClient _dogClient = new("dog", string.Empty, "DogClient description", [], [], _animalClient.Name);
-        private static readonly InputClient _catClient = new("cat", string.Empty, "CatClient description", [], [], _animalClient.Name);
-        private static readonly InputClient _hawkClient = new("hawkClient", string.Empty, "HawkClient description", [], [], _animalClient.Name);
-        private static readonly InputClient _huskyClient = new("husky", string.Empty, "HuskyClient description", [], [], _dogClient.Name);
+        private static readonly InputOperation _inputOperation = InputFactory.Operation("HelloAgain", parameters:
+            [
+                InputFactory.Parameter("p1", InputFactory.Array(InputPrimitiveType.String))
+            ]);
+        private static readonly InputClient _animalClient = new("animal", string.Empty, "AnimalClient description", [_inputOperation], [], TestClientName);
+        private static readonly InputClient _dogClient = new("dog", string.Empty, "DogClient description", [_inputOperation], [], _animalClient.Name);
+        private static readonly InputClient _catClient = new("cat", string.Empty, "CatClient description", [_inputOperation], [], _animalClient.Name);
+        private static readonly InputClient _hawkClient = new("hawkClient", string.Empty, "HawkClient description", [_inputOperation], [], _animalClient.Name);
+        private static readonly InputClient _huskyClient = new("husky", string.Empty, "HuskyClient description", [_inputOperation], [], _dogClient.Name);
 
         [SetUp]
         public void SetUp()

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/ClientProviders/ClientProviderTests.cs

@@ -7,6 +7,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
 using Microsoft.Generator.CSharp.ClientModel.Providers;
 using Microsoft.Generator.CSharp.Expressions;
 using Microsoft.Generator.CSharp.Input;
@@ -26,9 +27,13 @@ public class ClientProviderTests
         private const string KeyAuthCategory = "WithKeyAuth";
         private const string OAuth2Category = "WithOAuth2";
         private const string TestClientName = "TestClient";
-        private static readonly InputClient _animalClient = new("animal", "", "AnimalClient description", [], [], TestClientName);
-        private static readonly InputClient _dogClient = new("dog", "", "DogClient description", [], [], _animalClient.Name);
-        private static readonly InputClient _huskyClient = new("husky", "", "HuskyClient description", [], [], _dogClient.Name);
+        private static readonly InputOperation _inputOperation = InputFactory.Operation("HelloAgain", parameters:
+            [
+                InputFactory.Parameter("p1", InputFactory.Array(InputPrimitiveType.String))
+            ]);
+        private static readonly InputClient _animalClient = new("animal", "", "AnimalClient description", [_inputOperation], [], TestClientName);
+        private static readonly InputClient _dogClient = new("dog", "", "DogClient description", [_inputOperation], [], _animalClient.Name);
+        private static readonly InputClient _huskyClient = new("husky", "", "HuskyClient description", [_inputOperation], [], _dogClient.Name);
         private static readonly InputModelType _spreadModel = InputFactory.Model(
             "spreadModel",
             usage: InputModelTypeUsage.Spread,
@@ -63,6 +68,47 @@ public void SetUp()
                 clientPipelineApi: TestClientPipelineApi.Instance);
         }
 
+        [Test]
+        public async Task TestEmptyClient()
+        {
+            var client = InputFactory.Client(TestClientName);
+            var plugin = await MockHelpers.LoadMockPluginAsync(
+                clients: () => [client]);
+
+            var clientProvider = plugin.Object.OutputLibrary.TypeProviders.SingleOrDefault(t => t is ClientProvider && t.Name == TestClientName);
+            Assert.IsNull(clientProvider);
+        }
+
+        [Test]
+        public async Task TestNonEmptySubClient()
+        {
+            var client = InputFactory.Client(TestClientName);
+            var subClient = InputFactory.Client($"Sub{TestClientName}", [_inputOperation], [], client.Name);
+            var plugin = await MockHelpers.LoadMockPluginAsync(
+                clients: () => [client, subClient]);
+
+            var subClientProvider = plugin.Object.OutputLibrary.TypeProviders.SingleOrDefault(t => t is ClientProvider && t.Name == subClient.Name);
+            Assert.IsNotNull(subClientProvider);
+
+            var clientProvider = plugin.Object.OutputLibrary.TypeProviders.SingleOrDefault(t => t is ClientProvider && t.Name == TestClientName);
+            Assert.IsNotNull(clientProvider);
+        }
+
+        [Test]
+        public async Task TestEmptySubClient()
+        {
+            var client = InputFactory.Client(TestClientName);
+            var subClient = InputFactory.Client($"Sub{TestClientName}", [], [], client.Name);
+            var plugin = await MockHelpers.LoadMockPluginAsync(
+                clients: () => [client, subClient]);
+
+            var subClientProvider = plugin.Object.OutputLibrary.TypeProviders.SingleOrDefault(t => t is ClientProvider && t.Name == subClient.Name);
+            Assert.IsNull(subClientProvider);
+
+            var clientProvider = plugin.Object.OutputLibrary.TypeProviders.SingleOrDefault(t => t is ClientProvider && t.Name == TestClientName);
+            Assert.IsNull(clientProvider);
+        }
+
         [Test]
         public void TestBuildProperties()
         {

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/RestClientProviders/RestClientProviderCustomizationTests.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Generator.CSharp.ClientModel.Providers;
+using Microsoft.Generator.CSharp.Input;
 using Microsoft.Generator.CSharp.Primitives;
 using Microsoft.Generator.CSharp.Tests.Common;
 using NUnit.Framework;
@@ -16,7 +17,11 @@ public class RestClientProviderCustomizationTests
         [Test]
         public async Task CanChangeClientNamespace()
         {
-            var inputClient = InputFactory.Client("TestClient");
+            var inputOperation = InputFactory.Operation("HelloAgain", parameters:
+            [
+                InputFactory.Parameter("p1", InputFactory.Array(InputPrimitiveType.String))
+            ]);
+            var inputClient = InputFactory.Client("TestClient", [inputOperation]);
             var plugin = await MockHelpers.LoadMockPluginAsync(
                 clients: () => [inputClient],
                 compilation: async () => await Helpers.GetCompilationFromDirectoryAsync());

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/RestClientProviders/TestData/RestClientProviderCustomizationTests/CanChangeClientNamespace.cs

@@ -2,10 +2,31 @@
 
 #nullable disable
 
+using System.ClientModel;
+using System.ClientModel.Primitives;
+using Sample;
+
 namespace Sample.Custom
 {
     /// <summary></summary>
     public partial class TestClient
     {
+        private static global::System.ClientModel.Primitives.PipelineMessageClassifier _pipelineMessageClassifier200;
+
+        private static global::System.ClientModel.Primitives.PipelineMessageClassifier PipelineMessageClassifier200 => _pipelineMessageClassifier200 = global::System.ClientModel.Primitives.PipelineMessageClassifier.Create(stackalloc ushort[] { 200 });
+
+        internal global::System.ClientModel.Primitives.PipelineMessage CreateHelloAgainRequest(global::System.ClientModel.BinaryContent content, global::System.ClientModel.Primitives.RequestOptions options)
+        {
+            global::System.ClientModel.Primitives.PipelineMessage message = Pipeline.CreateMessage();
+            message.ResponseClassifier = PipelineMessageClassifier200;
+            global::System.ClientModel.Primitives.PipelineRequest request = message.Request;
+            request.Method = "GET";
+            global::Sample.ClientUriBuilder uri = new global::Sample.ClientUriBuilder();
+            uri.Reset(_endpoint);
+            request.Uri = uri.ToUri();
+            request.Content = content;
+            message.Apply(options);
+            return message;
+        }
     }
 }