Fix to use custom code to update a property type (#54158)

* wip

* bump version of azure generator

Author: live1206

eng/Packages.Data.props

@@ -487,6 +487,6 @@
   <PropertyGroup>
     <TestProxyVersion>1.0.0-dev.20250930.1</TestProxyVersion>
     <UnbrandedGeneratorVersion>1.0.0-alpha.20251125.2</UnbrandedGeneratorVersion>
-    <AzureGeneratorVersion>1.0.0-alpha.20251114.1</AzureGeneratorVersion>
+    <AzureGeneratorVersion>1.0.0-alpha.20251125.3</AzureGeneratorVersion>
   </PropertyGroup>
 </Project>

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

@@ -31,8 +31,10 @@ public static IReadOnlyList<PropertyProvider> GetAllProperties(ModelProvider pro
             while (baseTypes.TryPop(out var item))
             {
                 result.AddRange(item.Properties);
+                result.AddRange(item.CustomCodeView?.Properties ?? []);
             }
             result.AddRange(propertyModelProvider.Properties);
+            result.AddRange(propertyModelProvider.CustomCodeView?.Properties ?? []);
             return result;
         }
 

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

@@ -305,7 +305,7 @@ private void FlattenModel(ModelProvider model)
             var isFlattenProperty = false;
             var isSafeFlatten = false;
             var propertyMap = new Dictionary<PropertyProvider, List<FlattenPropertyInfo>>();
-            foreach (var internalProperty in model.Properties)
+            foreach (var internalProperty in model.Properties.Concat(model.CustomCodeView?.Properties ?? []))
             {
                 // we need to flatten the inner property type first
                 var propertyType = internalProperty.Type;
@@ -315,16 +315,24 @@ private void FlattenModel(ModelProvider model)
                     FlattenModel(propertyModel);
                 }
 
+                if (!(ManagementClientGenerator.Instance.TypeFactory.CSharpTypeMap.TryGetValue(internalProperty.Type, out var typeProvider)
+                    && typeProvider is ModelProvider modelProvider))
+                {
+                    continue;
+                }
+
+                var innerProperties = PropertyHelpers.GetAllProperties(modelProvider);
+
                 // handle `@flattenProperty`
                 if (ManagementClientGenerator.Instance.OutputLibrary.OutputFlattenPropertyMap.TryGetValue(model, out var propertiesToFlatten) && propertiesToFlatten.Contains(internalProperty))
                 {
-                    isFlattenProperty = PropertyFlatten(model, propertyMap, internalProperty);
+                    isFlattenProperty = true;
+                    PropertyFlatten(model, modelProvider, innerProperties, propertyMap, internalProperty);
                     continue;
                 }
                 // safe flatten single property
-                else if (ManagementClientGenerator.Instance.TypeFactory.CSharpTypeMap.TryGetValue(internalProperty.Type, out var typeProvider) && typeProvider is ModelProvider modelProvider)
+                else
                 {
-                    var innerProperties = PropertyHelpers.GetAllProperties(modelProvider);
                     // only safe flatten single property
                     if (innerProperties.Count != 1)
                     {
@@ -344,7 +352,7 @@ private void FlattenModel(ModelProvider model)
                         continue;
                     }
 
-                    isSafeFlatten = SafeFlatten(model, propertyMap, internalProperty, modelProvider);
+                    isSafeFlatten = SafeFlatten(model, innerProperties, propertyMap, internalProperty, modelProvider);
                 }
             }
 
@@ -364,61 +372,53 @@ private void FlattenModel(ModelProvider model)
             }
         }
 
-        private bool PropertyFlatten(ModelProvider model, Dictionary<PropertyProvider, List<FlattenPropertyInfo>> propertyMap, PropertyProvider internalProperty)
+        private void PropertyFlatten(ModelProvider model, ModelProvider propertyModel, IReadOnlyList<PropertyProvider> innerProperties, Dictionary<PropertyProvider, List<FlattenPropertyInfo>> propertyMap, PropertyProvider internalProperty)
         {
-            var isFlattened = false;
             var flattenedProperties = new List<(bool IsOverriddenValueType, PropertyProvider FlattenedProperty)>();
-            if (ManagementClientGenerator.Instance.TypeFactory.CSharpTypeMap.TryGetValue(internalProperty.Type, out var typeProvider)
-                && typeProvider is ModelProvider modelProvider)
-            {
-                isFlattened = true;
 
-                foreach (var innerProperty in PropertyHelpers.GetAllProperties(modelProvider))
+            foreach (var innerProperty in innerProperties)
+            {
+                if (!innerProperty.Modifiers.HasFlag(MethodSignatureModifiers.Public))
                 {
-                    if (!innerProperty.Modifiers.HasFlag(MethodSignatureModifiers.Public))
-                    {
-                        continue;
-                    }
-                    UpdateFlattenTypeCollectionProperty(internalProperty, innerProperty, model);
-                    // flatten the property to public and associate it with the internal property
-                    var (_, includeGetterNullCheck, _) = PropertyHelpers.GetFlags(internalProperty, innerProperty);
-                    var flattenPropertyName = innerProperty.Name; // TODO: handle name conflicts
-                    var flattenPropertyBody = new MethodPropertyBody(
-                        PropertyHelpers.BuildGetter(includeGetterNullCheck, internalProperty, modelProvider, innerProperty),
-                        !internalProperty.Body.HasSetter || !innerProperty.Body.HasSetter ? null : PropertyHelpers.BuildSetterForPropertyFlatten(modelProvider, internalProperty, innerProperty)
-                    );
-
-                    // If the inner property is a value type, we need to ensure that we handle the nullability correctly.
-                    var isOverriddenValueType = innerProperty.Type.IsValueType && !innerProperty.Type.IsNullable;
-                    var flattenedProperty =
-                        new FlattenedPropertyProvider(
-                            innerProperty.Description,
-                            innerProperty.Modifiers,
-                            innerProperty.Type,
-                            flattenPropertyName,
-                            flattenPropertyBody,
-                            model,
-                            internalProperty,
-                            innerProperty,
-                            innerProperty.ExplicitInterface,
-                            ConstructFlattenPropertyWireInfo(internalProperty, innerProperty),
-                            innerProperty.IsRef,
-                            innerProperty.Attributes);
-
-                    if (propertyMap.TryGetValue(internalProperty, out var value))
-                    {
-                        value.Add(new(flattenedProperty, internalProperty));
-                    }
-                    else
-                    {
-                        propertyMap.Add(internalProperty, new List<FlattenPropertyInfo> { new(flattenedProperty, internalProperty) });
-                    }
+                    continue;
+                }
+                UpdateFlattenTypeCollectionProperty(internalProperty, innerProperty, model);
+                // flatten the property to public and associate it with the internal property
+                var (_, includeGetterNullCheck, _) = PropertyHelpers.GetFlags(internalProperty, innerProperty);
+                var flattenPropertyName = innerProperty.Name; // TODO: handle name conflicts
+                var flattenPropertyBody = new MethodPropertyBody(
+                    PropertyHelpers.BuildGetter(includeGetterNullCheck, internalProperty, propertyModel, innerProperty),
+                    !internalProperty.Body.HasSetter || !innerProperty.Body.HasSetter ? null : PropertyHelpers.BuildSetterForPropertyFlatten(propertyModel, internalProperty, innerProperty)
+                );
+
+                // If the inner property is a value type, we need to ensure that we handle the nullability correctly.
+                var isOverriddenValueType = innerProperty.Type.IsValueType && !innerProperty.Type.IsNullable;
+                var flattenedProperty =
+                    new FlattenedPropertyProvider(
+                        innerProperty.Description,
+                        innerProperty.Modifiers,
+                        innerProperty.Type,
+                        flattenPropertyName,
+                        flattenPropertyBody,
+                        model,
+                        internalProperty,
+                        innerProperty,
+                        innerProperty.ExplicitInterface,
+                        ConstructFlattenPropertyWireInfo(internalProperty, innerProperty),
+                        innerProperty.IsRef,
+                        innerProperty.Attributes);
+
+                if (propertyMap.TryGetValue(internalProperty, out var value))
+                {
+                    value.Add(new(flattenedProperty, internalProperty));
+                }
+                else
+                {
+                    propertyMap.Add(internalProperty, new List<FlattenPropertyInfo> { new(flattenedProperty, internalProperty) });
                 }
-                // make the internalized properties internal
-                internalProperty.Update(modifiers: internalProperty.Modifiers & ~MethodSignatureModifiers.Public | MethodSignatureModifiers.Internal);
             }
-
-            return isFlattened;
+            // make the internalized properties internal
+            internalProperty.Update(modifiers: internalProperty.Modifiers & ~MethodSignatureModifiers.Public | MethodSignatureModifiers.Internal);
         }
 
         private static PropertyWireInformation? ConstructFlattenPropertyWireInfo(PropertyProvider internalProperty, PropertyProvider innerProperty)
@@ -438,10 +438,10 @@ private bool PropertyFlatten(ModelProvider model, Dictionary<PropertyProvider, L
                 innerPropertyWireInfo.IsHttpMetadata);
         }
 
-        private bool SafeFlatten(ModelProvider model, Dictionary<PropertyProvider, List<FlattenPropertyInfo>> propertyMap, PropertyProvider internalProperty, ModelProvider modelProvider)
+        private bool SafeFlatten(ModelProvider model, IReadOnlyList<PropertyProvider> innerProperties, Dictionary<PropertyProvider, List<FlattenPropertyInfo>> propertyMap, PropertyProvider internalProperty, ModelProvider modelProvider)
         {
             bool isFlattened;
-            var innerProperty = modelProvider.Properties.Single();
+            var innerProperty = innerProperties.Single();
             isFlattened = true;
 
             // flatten the single property to public and associate it with the internal property

eng/packages/http-client-csharp-mgmt/generator/TestProjects/Local/Mgmt-TypeSpec/src/Custom/BarQuotaProperties.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+namespace Azure.Generator.MgmtTypeSpec.Tests.Models
+{
+    internal partial class BarQuotaProperties
+    {
+        /// <summary> enabled. </summary>
+        [WirePath("left")]
+        public string Left { get; set; }
+    }
+}