DateOnly in .net 6 causes indexing error, add support for it

Is your feature request related to a problem? Please describe. Trying to index an object with DateOnly wil cause the following error:

Failed to index document 618252e5fd34fc54f4d94ac3: Type: mapper_parsing_exception Reason: “failed to parse field [dueAt.dayOfWeek] of type [integer] in document with id ‘618252e5fd34fc54f4d94ac3’. Preview of field’s value: ‘Friday’” CausedBy: “Type: number_format_exception Reason: “For input string: “Friday”””

Describe the solution you’d like Proper support for DateOnly, aka a working serializer and deserializer.

Describe alternatives you’ve considered Some custom serializer, but don’t know how to implement this.

Additional context

Settings:

var settings = new ConnectionSettings(pool, (builtin, settings) => new JsonNetSerializer(builtin, settings,
            contractJsonConverters: new JsonConverter[] {new StringEnumConverter()})).EnableDebugMode();

StringEnumConverter seems to break support for DateOnly.

[stevejgordon]

@niemyjski Adding a specific NET6.0 target for 7.x is not going to a priority while we work on v8. I did take a spike on that a while back and ran into some issues, although I need to revisit what those issues where. Given that, as you note, even STJ doesn’t yet support these new DateOnly and TimeOnly types, our general advice is to avoid them on source types. For 8.x we’ll likely be able to support those with the STJ library. One the benefits of the move to STJ as the default source serializer is that custom converters work OOB and provide more standard ways to control advanced serialization.

Thanks for linking to the Newtonsoft PR. Good to see support coming there soon. Once supported there, a workaround would be to use our NewtonsoftJson package to gain support that way. You could also add in a custom ISerializer as a current workaround with a serializer that supports these types. Implementing ISerializer is the intended way for consumers to “extend” the client to support any behaviour for source serialization that is required.

[stevejgordon]

@sjd2021 It’s been added for .NET 7.0 which is not yet released and supported until November. Our new client targets STJ so consumers will be able to leverage those types by default in that release.