Recalculate modifiers during namespace update

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/src/Providers/TypeProvider.cs

@@ -516,6 +516,7 @@ public void Update(
                 // Reset the custom code view to reflect the new namespace
                 _customCodeView = new(BuildCustomCodeView(Type.Name, @namespace));
                 _lastContractView = new(BuildLastContractView(Type.Name, @namespace));
+                _declarationModifiers = BuildDeclarationModifiersInternal(); // recalculate declaration modifiers
                 Type.Update(@namespace: _customCodeView.Value?.Type.Namespace ?? @namespace);
             }
 

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ModelProviders/ModelCustomizationTests.cs

@@ -1321,6 +1321,28 @@ public async Task CanCustomizeModelNameWithCustomizedNamespace()
             Assert.AreEqual("NewNamespace", updatedModel.Type.Namespace);
         }
 
+        [Test]
+        public async Task CanCustomizeAccessibilityWithCustomizedNamespace()
+        {
+            await MockHelpers.LoadMockGeneratorAsync(compilation: async () => await Helpers.GetCompilationFromDirectoryAsync());
+
+            var props = new[]
+            {
+                InputFactory.Property("prop1", InputFactory.Array(InputPrimitiveType.String))
+            };
+
+            var inputModel = InputFactory.Model("mockInputModel", properties: props);
+            var modelTypeProvider = new ModelProvider(inputModel);
+
+            var namespaceVisitor = new TestNamespaceVisitor();
+            var nameVisitor = new TestNameVisitor();
+            var updatedModel = nameVisitor.InvokeVisit(namespaceVisitor.InvokeVisit(modelTypeProvider)!);
+            Assert.IsNotNull(updatedModel);
+            Assert.AreEqual("CustomizedModel", updatedModel!.Name);
+            Assert.AreEqual("NewNamespace", updatedModel.Type.Namespace);
+            Assert.IsTrue(updatedModel.DeclarationModifiers.HasFlag(TypeSignatureModifiers.Internal));
+        }
+
         [Test]
         public async Task DiscriminatorPropertyNotGeneratedIfOnCustomizedBase()
         {

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ModelProviders/TestData/ModelCustomizationTests/CanCustomizeAccessibilityWithCustomizedNamespace/CustommizedModel.cs

@@ -0,0 +1,9 @@
+
+using System;
+using SampleTypeSpec;
+
+namespace NewNamespace;
+
+internal class MockInputModel
+{
+}