[Azure Mgmt Generator] Skip generation of mockable resources without methods (#54137)

Co-authored-by: ArcturusZhang <[email protected]>
Co-authored-by: copilot-swe-agent[bot] <[email protected]>

Author: Copilot

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/ManagementOutputLibrary.cs

@@ -138,20 +138,28 @@ _mockableResources is not null ||
                 resourceDict,
                 resourceMethodCategories,
                 ManagementClientGenerator.Instance.InputLibrary.NonResourceMethods);
-            var mockableArmClientResource = new MockableArmClientProvider(_resources);
+            var mockableArmClientResource = MockableArmClientProvider.TryCreate(_resources);
             var mockableResources = new Dictionary<ResourceScope, MockableResourceProvider>(resourcesAndMethodsPerScope.Count);
             foreach (var (scope, (resourcesInScope, resourceMethods, nonResourceMethods)) in resourcesAndMethodsPerScope)
             {
-                if (scope != ResourceScope.Extension &&
-                    (resourcesInScope.Count > 0 || resourceMethods.Count > 0 || nonResourceMethods.Count > 0))
+                if (scope != ResourceScope.Extension)
                 {
-                    var mockableExtension = new MockableResourceProvider(scope, resourcesInScope, resourceMethods, nonResourceMethods);
-                    mockableResources.Add(scope, mockableExtension);
+                    var mockableExtension = MockableResourceProvider.TryCreate(scope, resourcesInScope, resourceMethods, nonResourceMethods);
+                    if (mockableExtension != null)
+                    {
+                        mockableResources.Add(scope, mockableExtension);
+                    }
                 }
             }
 
             _mockableResourcesByScopeDict = mockableResources;
-            _mockableResources = [mockableArmClientResource, ..mockableResources.Values];
+            var allMockableResources = new List<MockableResourceProvider>();
+            if (mockableArmClientResource != null)
+            {
+                allMockableResources.Add(mockableArmClientResource);
+            }
+            allMockableResources.AddRange(mockableResources.Values);
+            _mockableResources = allMockableResources;
             _extensionProvider = new ExtensionProvider(_mockableResources);
 
             static Dictionary<ResourceScope, ResourcesAndNonResourceMethodsInScope> BuildResourcesAndNonResourceMethods(

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/MockableArmClientProvider.cs

@@ -17,11 +17,25 @@ namespace Azure.Generator.Management.Providers
     internal sealed class MockableArmClientProvider : MockableResourceProvider
     {
         // TODO -- we also need to put operations here when we want to support scope resources/operations https://github.com/Azure/azure-sdk-for-net/issues/51821
-        public MockableArmClientProvider(IReadOnlyList<ResourceClientProvider> resources)
+        private MockableArmClientProvider(IReadOnlyList<ResourceClientProvider> resources)
             : base(typeof(ArmClient), RequestPathPattern.Tenant, resources, new Dictionary<ResourceClientProvider, IReadOnlyList<ResourceMethod>>(), [])
         {
         }
 
+        /// <summary>
+        /// Creates a new instance of <see cref="MockableArmClientProvider"/> if there are resources to generate methods for.
+        /// </summary>
+        /// <param name="resources">The resources to generate methods for.</param>
+        /// <returns>A new instance of <see cref="MockableArmClientProvider"/> if there are resources, otherwise null.</returns>
+        public static MockableArmClientProvider? TryCreate(IReadOnlyList<ResourceClientProvider> resources)
+        {
+            if (resources.Count == 0)
+            {
+                return null;
+            }
+            return new MockableArmClientProvider(resources);
+        }
+
         protected override MethodProvider[] BuildMethods()
         {
             var methods = new List<MethodProvider>(_resources.Count);

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/MockableResourceProvider.cs

@@ -38,11 +38,28 @@ internal class MockableResourceProvider : TypeProvider
         /// <param name="resources">the resources in this scope.</param>
         /// <param name="resourceMethods">the resource methods that belong to this scope.</param>
         /// <param name="nonResourceMethods">the non-resource methods that belong to this scope.</param>
-        public MockableResourceProvider(ResourceScope resourceScope, IReadOnlyList<ResourceClientProvider> resources, IReadOnlyDictionary<ResourceClientProvider, IReadOnlyList<ResourceMethod>> resourceMethods, IReadOnlyList<NonResourceMethod> nonResourceMethods)
+        private MockableResourceProvider(ResourceScope resourceScope, IReadOnlyList<ResourceClientProvider> resources, IReadOnlyDictionary<ResourceClientProvider, IReadOnlyList<ResourceMethod>> resourceMethods, IReadOnlyList<NonResourceMethod> nonResourceMethods)
             : this(ResourceHelpers.GetArmCoreTypeFromScope(resourceScope), RequestPathPattern.GetFromScope(resourceScope), resources, resourceMethods, nonResourceMethods)
         {
         }
 
+        /// <summary>
+        /// Creates a new instance of <see cref="MockableResourceProvider"/> if there are resources or methods to generate.
+        /// </summary>
+        /// <param name="resourceScope">The scope of this mockable resource.</param>
+        /// <param name="resources">The resources in this scope.</param>
+        /// <param name="resourceMethods">The resource methods that belong to this scope.</param>
+        /// <param name="nonResourceMethods">The non-resource methods that belong to this scope.</param>
+        /// <returns>A new instance of <see cref="MockableResourceProvider"/> if there are resources or methods, otherwise null.</returns>
+        public static MockableResourceProvider? TryCreate(ResourceScope resourceScope, IReadOnlyList<ResourceClientProvider> resources, IReadOnlyDictionary<ResourceClientProvider, IReadOnlyList<ResourceMethod>> resourceMethods, IReadOnlyList<NonResourceMethod> nonResourceMethods)
+        {
+            if (resources.Count == 0 && resourceMethods.Count == 0 && nonResourceMethods.Count == 0)
+            {
+                return null;
+            }
+            return new MockableResourceProvider(resourceScope, resources, resourceMethods, nonResourceMethods);
+        }
+
         private protected MockableResourceProvider(CSharpType armCoreType, RequestPathPattern contextualPath, IReadOnlyList<ResourceClientProvider> resources, IReadOnlyDictionary<ResourceClientProvider, IReadOnlyList<ResourceMethod>> resourceMethods, IReadOnlyList<NonResourceMethod> nonResourceMethods)
         {
             _resources = resources;

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/test/Providers/ExtensionProviderTests.cs

@@ -70,5 +70,24 @@ public void Verify_GetResourceByIdMethods()
             Assert.IsNotNull(getMethod);
             Assert.AreEqual(resource!.Type, getMethod!.Signature.ReturnType);
         }
+
+        [TestCase]
+        public void Verify_MockableResourcesWithNoMethods_AreNotGenerated()
+        {
+            // Verify that all MockableResourceProvider instances in the output have at least one method
+            // This ensures that mockable resources without methods are filtered out
+            var mockableResources = _plugin.OutputLibrary.TypeProviders
+                .OfType<MockableResourceProvider>().ToList();
+
+            // With resources defined, there should be mockable resources
+            Assert.That(mockableResources.Count, Is.GreaterThan(0), "There should be at least one mockable resource when resources are defined");
+
+            // All mockable resources in the output should have at least one method
+            foreach (var mockableResource in mockableResources)
+            {
+                Assert.That(mockableResource.Methods.Count, Is.GreaterThan(0),
+                    $"MockableResourceProvider '{mockableResource.Name}' should have at least one method to be included in the output.");
+            }
+        }
     }
 }