[http-client-csharp] Fix AOT compatibility issues in generated methods

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

@@ -380,7 +380,7 @@ private ValueExpression GetResultConversion(ClientResponseApi result, HttpRespon
                 }
                 else
                 {
-                    return response.Content().ToObjectFromJson(responseBodyType.OutputType);
+                    return ModelReaderWriterSnippets.Read(response.Content(), responseBodyType.OutputType);
                 }
             }
             if (responseBodyType.IsDictionary)
@@ -391,7 +391,7 @@ private ValueExpression GetResultConversion(ClientResponseApi result, HttpRespon
                 }
                 else
                 {
-                    return response.Content().ToObjectFromJson(responseBodyType.OutputType);
+                   return ModelReaderWriterSnippets.Read(response.Content(), responseBodyType.OutputType);
                 }
             }
             if (responseBodyType.Equals(typeof(string)) && ServiceMethod.Operation.Responses.Any(r => r.IsErrorResponse is false && r.ContentTypes.Contains("text/plain")))
@@ -400,11 +400,11 @@ private ValueExpression GetResultConversion(ClientResponseApi result, HttpRespon
             }
             if (responseBodyType.IsFrameworkType)
             {
-                return response.Content().ToObjectFromJson(responseBodyType);
+                return ModelReaderWriterSnippets.Read(response.Content(), responseBodyType);
             }
             if (responseBodyType.IsEnum)
             {
-                return responseBodyType.ToEnum(response.Content().ToObjectFromJson(responseBodyType.UnderlyingEnumType));
+                return responseBodyType.ToEnum(ModelReaderWriterSnippets.Read(response.Content(), responseBodyType.UnderlyingEnumType));
             }
             return result.CastTo(responseBodyType);
         }

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Snippets/ModelReaderWriterSnippets.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.ClientModel;
+using System.ClientModel.Primitives;
+using Microsoft.TypeSpec.Generator.Expressions;
+using Microsoft.TypeSpec.Generator.Primitives;
+using static Microsoft.TypeSpec.Generator.Snippets.Snippet;
+
+namespace Microsoft.TypeSpec.Generator.ClientModel.Snippets
+{
+    internal static class ModelReaderWriterSnippets
+    {
+        public static InvokeMethodExpression Read(ValueExpression data, CSharpType type)
+        {
+            return Static(typeof(ModelReaderWriter)).Invoke(
+                nameof(ModelReaderWriter.Read),
+                [data, ModelSerializationExtensionsSnippets.Wire, ModelReaderWriterContextSnippets.Default],
+                new CSharpType[] { type });
+        }
+    }
+}

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/ScmMethodProviderCollectionTests.cs

@@ -1133,5 +1133,66 @@ await MockHelpers.LoadMockGeneratorAsync(
             Assert.IsNotNull(collectionResultDefinition, "CollectionResultDefinition should be added even when paging methods are customized");
         }
 
+        [TestCase("ListOfStrings", typeof(IReadOnlyList<string>))]
+        [TestCase("DictionaryOfInts", typeof(IReadOnlyDictionary<string, int>))]
+        [TestCase("Int32", typeof(int))]
+        [TestCase("Enum", typeof(int))] // Enum is tested with underlying type
+        public void AotCompatibleModelReaderWriterReadMethods(string testCaseName, Type returnType)
+        {
+            InputType? inputType = null;
+            bool isEnum = testCaseName == "Enum";
+
+            if (testCaseName == "ListOfStrings")
+            {
+                inputType = InputFactory.Array(InputPrimitiveType.String);
+            }
+            else if (testCaseName == "DictionaryOfInts")
+            {
+                inputType = InputFactory.Dictionary(InputPrimitiveType.Int32);
+            }
+            else if (testCaseName == "Int32")
+            {
+                inputType = InputPrimitiveType.Int32;
+            }
+            else if (isEnum)
+            {
+                inputType = InputFactory.Int32Enum("TestEnum", [("Value1", 1), ("Value2", 2)]);
+            }
+
+            var inputOperation = InputFactory.Operation(
+                "GetData",
+                responses: [InputFactory.OperationResponse([200], inputType!)]);
+
+            var inputServiceMethod = InputFactory.BasicServiceMethod("GetData", inputOperation);
+            var inputClient = InputFactory.Client("TestClient", methods: [inputServiceMethod]);
+
+            MockHelpers.LoadMockGenerator();
+            var client = ScmCodeModelGenerator.Instance.TypeFactory.CreateClient(inputClient);
+
+            var methodCollection = new ScmMethodProviderCollection(inputServiceMethod, client!);
+            Assert.IsNotNull(methodCollection);
+
+            var convenienceMethod = methodCollection.FirstOrDefault(m
+                => m.Signature.Parameters.All(p => p.Name != "options")
+                   && m.Signature.Name == $"{inputOperation.Name.ToIdentifierName()}");
+
+            Assert.IsNotNull(convenienceMethod);
+
+            // Verify the body uses ModelReaderWriter.Read with context parameter
+            var bodyText = convenienceMethod!.BodyStatements!.ToDisplayString();
+
+            StringAssert.Contains("ModelReaderWriter.Read", bodyText, 
+                "Method should use ModelReaderWriter.Read for AOT compatibility");
+            StringAssert.Contains("SampleContext.Default", bodyText, 
+                "Method should include ModelReaderWriterContext.Default parameter");
+            StringAssert.Contains("ModelSerializationExtensions.WireOptions", bodyText,
+                "Method should include WireOptions parameter");
+
+            // Compare with expected output (normalize line endings for cross-platform compatibility)
+            var expected = Helpers.GetExpectedFromFile(testCaseName).Replace("\r\n", "\n");
+            var actual = bodyText.Replace("\r\n", "\n");
+            Assert.AreEqual(expected, actual);
+        }
+
     }
 }

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/AotCompatibleModelReaderWriterReadMethods(DictionaryOfInts).cs

@@ -0,0 +1,2 @@
+global::System.ClientModel.ClientResult result = this.GetData(cancellationToken.ToRequestOptions());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<global::System.Collections.Generic.IReadOnlyDictionary<string, int>>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/AotCompatibleModelReaderWriterReadMethods(Enum).cs

@@ -0,0 +1,2 @@
+global::System.ClientModel.ClientResult result = this.GetData(cancellationToken.ToRequestOptions());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<int>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default).ToTestEnum(), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/AotCompatibleModelReaderWriterReadMethods(Int32).cs

@@ -0,0 +1,2 @@
+global::System.ClientModel.ClientResult result = this.GetData(cancellationToken.ToRequestOptions());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<int>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/AotCompatibleModelReaderWriterReadMethods(ListOfStrings).cs

@@ -0,0 +1,2 @@
+global::System.ClientModel.ClientResult result = this.GetData(cancellationToken.ToRequestOptions());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<global::System.Collections.Generic.IReadOnlyList<string>>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Boolean).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<bool>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<bool>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(DateTimeOffset).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<global::System.DateTimeOffset>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<global::System.DateTimeOffset>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Double).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<double>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<double>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Int32).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<int>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<int>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Int64).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<long>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<long>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(Single).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<float>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<float>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(String).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<string>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<string>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/TestData/ScmMethodProviderCollectionTests/ScalarReturnTypeMethods(TimeSpan).cs

@@ -1,2 +1,2 @@
 global::System.ClientModel.ClientResult result = this.GetScalar(cancellationToken.ToRequestOptions());
-return global::System.ClientModel.ClientResult.FromValue(result.GetRawResponse().Content.ToObjectFromJson<global::System.TimeSpan>(), result.GetRawResponse());
+return global::System.ClientModel.ClientResult.FromValue(global::System.ClientModel.Primitives.ModelReaderWriter.Read<global::System.TimeSpan>(result.GetRawResponse().Content, global::Sample.ModelSerializationExtensions.WireOptions, global::Sample.SampleContext.Default), result.GetRawResponse());