[BUG][CSHARP][GENERICHOST] Write enum values in expected JSON format (#21698)

* Use ValueConverter method for enums to output in the correct JSON format

* Fix doc comment

* Update samples

* Call ToString on return value of converter

* Update samples

* Update samples

* Add test

Author: alec-petersen

modules/openapi-generator/src/main/resources/csharp/modelEnum.mustache

@@ -141,7 +141,7 @@
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}} {{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}, JsonSerializerOptions options)
         {
-            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.ToString());
+            writer.WriteStringValue({{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}ValueConverter.ToJsonValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}).ToString());
         }
     }
 
@@ -172,14 +172,14 @@
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}} to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="{{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}? {{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}, JsonSerializerOptions options)
         {
-            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}?.ToString() ?? "null");
+            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.HasValue ? {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}ValueConverter.ToJsonValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.Value).ToString() : "null");
         }
     }
     {{/useGenericHost}}

samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/MarineAreaCode.cs

@@ -131,7 +131,7 @@ public override MarineAreaCode Read(ref Utf8JsonReader reader, Type typeToConver
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MarineAreaCode marineAreaCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(marineAreaCode.ToString());
+            writer.WriteStringValue(MarineAreaCodeValueConverter.ToJsonValue(marineAreaCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ public class MarineAreaCodeNullableJsonConverter : JsonConverter<MarineAreaCode?
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MarineAreaCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="marineAreaCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MarineAreaCode? marineAreaCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(marineAreaCode?.ToString() ?? "null");
+            writer.WriteStringValue(marineAreaCode.HasValue ? MarineAreaCodeValueConverter.ToJsonValue(marineAreaCode.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/StateTerritoryCode.cs

@@ -131,7 +131,7 @@ public override StateTerritoryCode Read(ref Utf8JsonReader reader, Type typeToCo
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, StateTerritoryCode stateTerritoryCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(stateTerritoryCode.ToString());
+            writer.WriteStringValue(StateTerritoryCodeValueConverter.ToJsonValue(stateTerritoryCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ public class StateTerritoryCodeNullableJsonConverter : JsonConverter<StateTerrit
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the StateTerritoryCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="stateTerritoryCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, StateTerritoryCode? stateTerritoryCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(stateTerritoryCode?.ToString() ?? "null");
+            writer.WriteStringValue(stateTerritoryCode.HasValue ? StateTerritoryCodeValueConverter.ToJsonValue(stateTerritoryCode.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs

@@ -116,7 +116,7 @@ public override ChildCatAllOfPetType Read(ref Utf8JsonReader reader, Type typeTo
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType.ToString());
+            writer.WriteStringValue(ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType).ToString());
         }
     }
 
@@ -147,14 +147,14 @@ public class ChildCatAllOfPetTypeNullableJsonConverter : JsonConverter<ChildCatA
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ChildCatAllOfPetType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="childCatAllOfPetType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType? childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType?.ToString() ?? "null");
+            writer.WriteStringValue(childCatAllOfPetType.HasValue ? ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs

@@ -130,7 +130,7 @@ public override EnumArraysArrayEnumInner Read(ref Utf8JsonReader reader, Type ty
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner.ToString());
+            writer.WriteStringValue(EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ public class EnumArraysArrayEnumInnerNullableJsonConverter : JsonConverter<EnumA
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysArrayEnumInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysArrayEnumInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner? enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysArrayEnumInner.HasValue ? EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs

@@ -130,7 +130,7 @@ public override EnumArraysJustSymbol Read(ref Utf8JsonReader reader, Type typeTo
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol.ToString());
+            writer.WriteStringValue(EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ public class EnumArraysJustSymbolNullableJsonConverter : JsonConverter<EnumArray
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysJustSymbol to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysJustSymbol"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol? enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysJustSymbol.HasValue ? EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs

@@ -144,7 +144,7 @@ public override EnumClass Read(ref Utf8JsonReader reader, Type typeToConvert, Js
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ public class EnumClassNullableJsonConverter : JsonConverter<EnumClass?>
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs

@@ -124,7 +124,7 @@ public override EnumTestEnumInteger Read(ref Utf8JsonReader reader, Type typeToC
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ public class EnumTestEnumIntegerNullableJsonConverter : JsonConverter<EnumTestEn
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger? enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumInteger.HasValue ? EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs

@@ -124,7 +124,7 @@ public override EnumTestEnumIntegerOnly Read(ref Utf8JsonReader reader, Type typ
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ public class EnumTestEnumIntegerOnlyNullableJsonConverter : JsonConverter<EnumTe
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly? enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumIntegerOnly.HasValue ? EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }

samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs

@@ -214,7 +214,7 @@ public override EnumTestEnumString Read(ref Utf8JsonReader reader, Type typeToCo
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString.ToString());
+            writer.WriteStringValue(EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ public class EnumTestEnumStringNullableJsonConverter : JsonConverter<EnumTestEnu
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString? enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumString.HasValue ? EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString.Value).ToString() : "null");
         }
     }
 }