System.Text.Json does not serialize most of the properties that Newtonsoft does.

[StingyJack]

Im trying to use the new Json package and finding its doing an incomplete job. I checked the MaxDepth and its using the default of 99. Why wont this serialize correctly?

This RoslynPad example will illustrate

#r "nuget:Newtonsoft.Json/12.0.3"
#r "nuget:System.Text.Json/5.0.0"
#r "nuget:GraphQL-Parser/5.3.3"
using System.Text.Json;
using GraphQLParser;
using Newtonsoft.Json;

var gql = "{" +
            "     human(id: \"1000\") " +
            "     {" +
            "         name," +
            "         height(unit: FOOT)" +
            "     }" +
            "}";

var source = new Source(gql);
var lexer = new Lexer();
var parser = new Parser(lexer);
var result = parser.Parse(source);


System.Text.Json.JsonSerializer.Serialize<object>(result, new JsonSerializerOptions { WriteIndented = true }).Dump();
Newtonsoft.Json.JsonConvert.SerializeObject(result, Formatting.Indented).Dump();

the first result is

{
  "Definitions": [
    {
      "Kind": 2,
      "Location": {
        "Start": 0,
        "End": 78
      },
      "Comment": null
    }
  ],
  "Kind": 1,
  "Location": {
    "Start": 0,
    "End": 78
  },
  "Comment": null
}

the second is

{
  "Definitions": [
    {
      "Directives": null,
      "Kind": 2,
      "Name": null,
      "Operation": 0,
      "SelectionSet": {
        "Kind": 5,
        "Selections": [
          {
            "Alias": null,
            "Arguments": [
              {
                "Kind": 7,
                "Name": {
                  "Kind": 0,
                  "Value": "id",
                  "Location": {
                    "Start": 12,
                    "End": 14
                  },
                  "Comment": null
                },
                "Value": {
                  "Kind": 13,
                  "Value": "1000",
                  "Location": {
                    "Start": 16,
                    "End": 22
                  },
                  "Comment": null
                },
                "Location": {
                  "Start": 12,
                  "End": 22
                },
                "Comment": null
              }
            ],
            "Directives": null,
            "Kind": 6,
            "Name": {
              "Kind": 0,
              "Value": "human",
              "Location": {
                "Start": 6,
                "End": 11
              },
              "Comment": null
            },
            "SelectionSet": {
              "Kind": 5,
              "Selections": [
                {
                  "Alias": null,
                  "Arguments": null,
                  "Directives": null,
                  "Kind": 6,
                  "Name": {
                    "Kind": 0,
                    "Value": "name",
                    "Location": {
                      "Start": 39,
                      "End": 43
                    },
                    "Comment": null
                  },
                  "SelectionSet": null,
                  "Location": {
                    "Start": 39,
                    "End": 43
                  },
                  "Comment": null
                },
                {
                  "Alias": null,
                  "Arguments": [
                    {
                      "Kind": 7,
                      "Name": {
                        "Kind": 0,
                        "Value": "unit",
                        "Location": {
                          "Start": 60,
                          "End": 64
                        },
                        "Comment": null
                      },
                      "Value": {
                        "Kind": 15,
                        "Value": "FOOT",
                        "Location": {
                          "Start": 66,
                          "End": 70
                        },
                        "Comment": null
                      },
                      "Location": {
                        "Start": 60,
                        "End": 70
                      },
                      "Comment": null
                    }
                  ],
                  "Directives": null,
                  "Kind": 6,
                  "Name": {
                    "Kind": 0,
                    "Value": "height",
                    "Location": {
                      "Start": 53,
                      "End": 59
                    },
                    "Comment": null
                  },
                  "SelectionSet": null,
                  "Location": {
                    "Start": 53,
                    "End": 71
                  },
                  "Comment": null
                }
              ],
              "Location": {
                "Start": 29,
                "End": 77
              },
              "Comment": null
            },
            "Location": {
              "Start": 6,
              "End": 77
            },
            "Comment": null
          }
        ],
        "Location": {
          "Start": 0,
          "End": 78
        },
        "Comment": null
      },
      "VariableDefinitions": null,
      "Location": {
        "Start": 0,
        "End": 78
      },
      "Comment": null
    }
  ],
  "Kind": 1,
  "Location": {
    "Start": 0,
    "End": 78
  },
  "Comment": null
}

[ericstj]

Here's the type being serialized: https://github.com/graphql-dotnet/parser/blob/master/src/GraphQLParser/AST/GraphQLDocument.cs

Looks to me like this contains a List<ASTNode> where ASTNode is an abstract base and the values are more derived types. I believe this is due to lack of support for polymorhpic serialization / deserialization. #29937

cc @layomia @steveharter

[StingyJack]

Whatever the reason is, the effect means that i cant trust the System.Text.Json package to handle serialization properly. I cant use something like that.

[Symbai]

Then you should up vote the requests about this, to show your interest #45189 otherwise we won't get support for it in .NET 6. Because .NET team believes this is an edge case scenario, when it isn't.

[ericstj]

Upvotes help. This one is on our radar for .NET 6.0. https://themesof.net/?q=Polymorphic%20is:open%20kinds:teui /cc @terrajobst

[layomia]

Closing as a dup of #29937.