simplify the serialization/deserialization hook (#5412)

Fixes #5411

Author: ArcturusZhang

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

@@ -842,15 +842,15 @@ private List<MethodBodyStatement> BuildDeserializePropertiesStatements(ScopedApi
 
             if (_additionalBinaryDataProperty != null)
             {
-                var binaryDataDeserializationValue = ClientModelPlugin.Instance.TypeFactory.GetValueTypeDeserializationExpression(
+                var binaryDataDeserializationValue = ClientModelPlugin.Instance.TypeFactory.DeserializeJsonValue(
                     _additionalBinaryDataProperty.Type.ElementType.FrameworkType, jsonProperty.Value(), SerializationFormat.Default);
                 propertyDeserializationStatements.Add(
                     _additionalBinaryDataProperty.AsVariableExpression.AsDictionary(_additionalBinaryDataProperty.Type).Add(jsonProperty.Name(), binaryDataDeserializationValue));
             }
             else if (rawBinaryData != null)
             {
                 var elementType = rawBinaryData.Type.Arguments[1].FrameworkType;
-                var rawDataDeserializationValue = ClientModelPlugin.Instance.TypeFactory.GetValueTypeDeserializationExpression(elementType, jsonProperty.Value(), SerializationFormat.Default);
+                var rawDataDeserializationValue = ClientModelPlugin.Instance.TypeFactory.DeserializeJsonValue(elementType, jsonProperty.Value(), SerializationFormat.Default);
                 propertyDeserializationStatements.Add(new IfStatement(_isNotEqualToWireConditionSnippet)
                 {
                     rawBinaryData.AsVariableExpression.AsDictionary(rawBinaryData.Type).Add(jsonProperty.Name(), rawDataDeserializationValue)
@@ -1267,11 +1267,11 @@ private ValueExpression CreateDeserializeValueExpression(CSharpType valueType, S
             valueType switch
             {
                 { IsFrameworkType: true } when valueType.FrameworkType == typeof(Nullable<>) =>
-                    ClientModelPlugin.Instance.TypeFactory.GetValueTypeDeserializationExpression(valueType.Arguments[0].FrameworkType, jsonElement, serializationFormat),
+                    ClientModelPlugin.Instance.TypeFactory.DeserializeJsonValue(valueType.Arguments[0].FrameworkType, jsonElement, serializationFormat),
                 { IsFrameworkType: true } =>
-                    ClientModelPlugin.Instance.TypeFactory.GetValueTypeDeserializationExpression(valueType.FrameworkType, jsonElement, serializationFormat),
+                    ClientModelPlugin.Instance.TypeFactory.DeserializeJsonValue(valueType.FrameworkType, jsonElement, serializationFormat),
                 { IsEnum: true } =>
-                    valueType.ToEnum(ClientModelPlugin.Instance.TypeFactory.GetValueTypeDeserializationExpression(valueType.UnderlyingEnumType!, jsonElement, serializationFormat)),
+                    valueType.ToEnum(ClientModelPlugin.Instance.TypeFactory.DeserializeJsonValue(valueType.UnderlyingEnumType!, jsonElement, serializationFormat)),
                 _ => valueType.Deserialize(jsonElement, _mrwOptionsParameterSnippet)
             };
 
@@ -1584,48 +1584,43 @@ private MethodBodyStatement CreateValueSerializationStatement(
             SerializationFormat serializationFormat,
             ValueExpression value)
         {
+            // append the `.Value` if needed (when the type is nullable and a value type)
+            value = value.NullableStructValue(type);
+
+            // now we just need to focus on how we serialize a value
             if (type.IsFrameworkType)
-                return ClientModelPlugin.Instance.TypeFactory.SerializeValueType(type, serializationFormat, value, type.FrameworkType, _utf8JsonWriterSnippet, _mrwOptionsParameterSnippet);
+                return ClientModelPlugin.Instance.TypeFactory.SerializeJsonValue(type.FrameworkType, value, _utf8JsonWriterSnippet, _mrwOptionsParameterSnippet, serializationFormat);
 
             if (!type.IsEnum)
                 return _utf8JsonWriterSnippet.WriteObjectValue(value.As(type), options: _mrwOptionsParameterSnippet);
 
-            var enumerableSnippet = value.NullableStructValue(type).As(type);
             if (type.IsStruct) //is extensible
             {
                 if (type.UnderlyingEnumType.Equals(typeof(string)))
-                    return _utf8JsonWriterSnippet.WriteStringValue(enumerableSnippet.Invoke(nameof(ToString)));
+                    return _utf8JsonWriterSnippet.WriteStringValue(value.Invoke(nameof(ToString)));
 
-                return _utf8JsonWriterSnippet.WriteNumberValue(enumerableSnippet.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
+                return _utf8JsonWriterSnippet.WriteNumberValue(value.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
             }
             else
             {
                 if (type.UnderlyingEnumType.Equals(typeof(int)))
                     // when the fixed enum is implemented as int, we cast to the value
-                    return _utf8JsonWriterSnippet.WriteNumberValue(enumerableSnippet.CastTo(type.UnderlyingEnumType));
+                    return _utf8JsonWriterSnippet.WriteNumberValue(value.CastTo(type.UnderlyingEnumType));
 
                 if (type.UnderlyingEnumType.Equals(typeof(string)))
-                    return _utf8JsonWriterSnippet.WriteStringValue(enumerableSnippet.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
+                    return _utf8JsonWriterSnippet.WriteStringValue(value.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
 
-                return _utf8JsonWriterSnippet.WriteNumberValue(enumerableSnippet.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
+                return _utf8JsonWriterSnippet.WriteNumberValue(value.Invoke($"ToSerial{type.UnderlyingEnumType.Name}"));
             }
         }
 
-        internal static MethodBodyStatement SerializeValueTypeCore(
-            CSharpType type,
-            SerializationFormat serializationFormat,
-            ValueExpression value,
+        internal static MethodBodyStatement SerializeJsonValueCore(
             Type valueType,
+            ValueExpression value,
             ScopedApi<Utf8JsonWriter> utf8JsonWriter,
-            ScopedApi<ModelReaderWriterOptions> mrwOptionsParameter)
+            ScopedApi<ModelReaderWriterOptions> mrwOptionsParameter,
+            SerializationFormat serializationFormat)
         {
-            if (valueType == typeof(Nullable<>))
-            {
-                valueType = type.Arguments[0].FrameworkType;
-            }
-
-            value = value.NullableStructValue(type);
-
             return valueType switch
             {
                 var t when t == typeof(JsonElement) =>
@@ -1656,7 +1651,7 @@ var t when ValueTypeIsNumber(t) =>
             };
         }
 
-        internal static ValueExpression GetValueTypeDeserializationExpressionCore(
+        internal static ValueExpression DeserializeJsonValueCore(
             Type valueType,
             ScopedApi<JsonElement> element,
             SerializationFormat format)

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

@@ -118,16 +118,15 @@ public ClientProvider CreateClient(InputClient inputClient)
             return methods;
         }
 
-        public virtual ValueExpression GetValueTypeDeserializationExpression(Type valueType, ScopedApi<JsonElement> element, SerializationFormat format)
-            => MrwSerializationTypeDefinition.GetValueTypeDeserializationExpressionCore(valueType, element, format);
+        public virtual ValueExpression DeserializeJsonValue(Type valueType, ScopedApi<JsonElement> element, SerializationFormat format)
+            => MrwSerializationTypeDefinition.DeserializeJsonValueCore(valueType, element, format);
 
-        public virtual MethodBodyStatement SerializeValueType(
-            CSharpType type,
-            SerializationFormat serializationFormat,
-            ValueExpression value,
+        public virtual MethodBodyStatement SerializeJsonValue(
             Type valueType,
+            ValueExpression value,
             ScopedApi<Utf8JsonWriter> utf8JsonWriter,
-            ScopedApi<ModelReaderWriterOptions> mrwOptionsParameter)
-            => MrwSerializationTypeDefinition.SerializeValueTypeCore(type, serializationFormat, value, valueType, utf8JsonWriter, mrwOptionsParameter);
+            ScopedApi<ModelReaderWriterOptions> mrwOptionsParameter,
+            SerializationFormat serializationFormat)
+            => MrwSerializationTypeDefinition.SerializeJsonValueCore(valueType, value, utf8JsonWriter, mrwOptionsParameter, serializationFormat);
     }
 }

packages/http-client-csharp/generator/Microsoft.Generator.CSharp.ClientModel/test/Providers/MrwSerializationTypeDefinitions/MrwSerializationTypeDefinitionTests.cs

@@ -712,7 +712,7 @@ public void TestIntSerializationStatement(
         [TestCase(typeof(sbyte), SerializationFormat.Default, ExpectedResult = "foo.GetSByte()")]
         public string TestIntDeserializeExpression(Type type, SerializationFormat format)
         {
-            var expr = MrwSerializationTypeDefinition.GetValueTypeDeserializationExpressionCore(type, new ScopedApi<JsonElement>(new VariableExpression(typeof(JsonElement), "foo")), format);
+            var expr = MrwSerializationTypeDefinition.DeserializeJsonValueCore(type, new ScopedApi<JsonElement>(new VariableExpression(typeof(JsonElement), "foo")), format);
             return expr.ToDisplayString();
         }