When an interface inherits an interface, System.Text.Json.JsonSerializer.Serialize only encodes the properties of the current interface into the json

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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The interface inherits the interface, and there should be content in the interface at the next level. Now System.Text.Json.JsonSerializer.Serialize encodes a string that contains only data for this level of interface, not the data for the interface's parent interface.
So I'm inglying back and hoping to get help.

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Original Comments

Feedback Bot on 2/23/2021, 00:07 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

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Original Solutions

(no solutions)

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Issue Details

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This issue has been moved from a ticket on Developer Community.

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The interface inherits the interface, and there should be content in the interface at the next level. Now System.Text.Json.JsonSerializer.Serialize encodes a string that contains only data for this level of interface, not the data for the interface's parent interface.
So I'm inglying back and hoping to get help.

---

Original Comments

Feedback Bot on 2/23/2021, 00:07 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

---

Original Solutions

(no solutions)

Author:	vsfeedback
Assignees:	-
Labels:	area-System.Text.Json, untriaged
Milestone:	-

[huoyaoyuan]

Should be by design - System.Text.Json uses variable/member type instead of object type, unless the variable type is object.

[centreboard]

In this example I would expect serialising as IFooBar to serialise both A and B, while it only serialises B in 5.0.3

using System;
using System.Text.Json;

var fooBar = new FooBar{A="Foo", B="Bar"};

Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(FooBar)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(IFooBar)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(Foo)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(IFoo)));


interface IFoo
{
    string A {get;set;}
}

interface IFooBar: IFoo
{
    string B {get;set;}
}

class Foo: IFoo {
    public string A {get;set;}
}

class FooBar: Foo, IFooBar
{
    public string B {get;set;}
}

{"B":"Bar","A":"Foo"}
{"B":"Bar"}
{"A":"Foo"}
{"A":"Foo"}

[ShuiFan0]

In this example I would expect serialising as IFooBar to serialise both A and B?

using System;
using System.Text.Json;

var fooBar = new FooBar{A="Foo", B="Bar"};

Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(FooBar)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(IFooBar)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(Foo)));
Console.WriteLine(JsonSerializer.Serialize(fooBar, typeof(IFoo)));


interface IFoo
{
    string A {get;set;}
}

interface IFooBar: IFoo
{
    string B {get;set;}
}

class Foo: IFoo {
    public string A {get;set;}
}

class FooBar: Foo, IFooBar
{
    public string B {get;set;}
}

{"B":"Bar","A":"Foo"}
{"B":"Bar"}
{"A":"Foo"}
{"A":"Foo"}

Yes,this I would expect

[huoyaoyuan]

Well, in this case your expectation is reasonable. I don't know about the design here.

[eiriktsarpalis]

Duplicate of #41749.