Using RequireNonOptionalPropertiesContractResolver causes invalid dictionary serialization

[tmoers]

I've noticed a bug that when you serialize a dictionary, e.g. something like

type Dto =
        { ints : IDictionary<string, int> }

in combination with the RequireNonOptionalPropertiesContractResolver serializes json
where all the dictionary keys are converted to lowercase.

[blumu]

@tmoers This is because the Compact.Strict serializer uses Camel casing: the type RequireNonOptionalPropertiesContractResolver defined under the Compact.Strict module inherits from CamelCasePropertyNamesContractResolver.

fsharplu/FSharpLu.Json/Compact.fs

Line 436 in cd3945d

inherit Newtonsoft.Json.Serialization.CamelCasePropertyNamesContractResolver()

If you don't want to use the default setting, you can defined your own contract resolver and make it inherit the DefaultContractResolver instead: https://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Serialization_DefaultContractResolver__ctor.htm

[tmoers]

Thanks for the quick response @blumu!

I get that this is the reason and thank you for explaining how to create a workaround, but I do wonder if the current behavior is correct. I opted in for more strict deserialization behavior, but instead information about property names is lost.

Anyhow, if this is considered correct behavior then just close the issue and I'll create my own resolver like you suggested.

Thanks for the help!

[blumu]

@tmoers I think you are right, we should consider this a bug since we really want the serializer to verify the requirement "serialize >> deserialize = identity". The fix would be to only apply camel casing to DU field names, but not to dictionary keys.