[anonymars]

Last I checked they stubbornly insisted on reinventing the wheel and ignoring everything in System.Runtime.Serialization so you had to redecorate everything with their new attributes. For example https://github.com/dotnet/runtime/issues/29975. So we stuck with Newtonsoft for the time being.

[WorldMaker]

There is a 3rd Party library for that now: https://github.com/zcsizmadia/ZCS.DataContractResolver

I haven't tried it because it has generally seemed easiest to use the new attributes. Though a large part of that is the shift from the WCF-era "opt-in" approach of DataContract/DataMember [0] versus the "opt-out" JsonIgnore approach where most of the transition is deleting lines because JsonIgnore is the exception rather than the rule. You could even keep DataContract/DataMember during the transition and just take an additive approach for JsonIgnore.

[0]: It was a good idea, in theory, but so annoying in practice.

[anonymars]

For me it was less not really about the opt-in part (after all, Newtonsoft works the same way) and more about stupid things like setting a name (DataMember), Enums, and in fact opting out (IgnoreDataMember)

It's especially annoying in libraries because the consumer might not even be using System.Text.Json, but you have to pull in the library anyway to apply its own attributes if you want it to work right. Just an overall awful smell given the existence of first-class framework attributes to do the same thing to avoid just that problem

Case in point: https://github.com/dotnet/efcore/pull/28084/files

[WorldMaker]

> but you have to pull in the library anyway

That library is also out-of-the-box in the BCL in .NET > 5, though. It's not an extra install (except for projects stuck in .NET 4.x).

I get the desire to avoid that sort of redundancy in the BCL itself, but also explicit is better than implicit, which was the baseline theory for why System.Runtime.Serialization was the way it was even as it added more and more implicit "conventions", and if System.Text.Json supported the SRS attributes out-of-the-box there would be just as many complaints about "implicit magic" or it not following WCF conventions hard enough and that making it harder to migrate things using SRS attributes when you wanted different behavior in JSON serialization than you would want in WCF SOAP serialization. SRS has too much WCF baggage, unfortunately for all of us.

Perhaps what's left of the disagreement here between us is if System.Text.Json counts as "first-class framework attributes" and it certainly seems that way to me in .NET 5+, and especially as we celebrate the release of .NET 10. It's a small redundancy in the BCL, but it's still just "as BCL" and "first-class".