Open Abrynos opened 7 months ago
In case you're wondering why I'm assigning an empty default value in the first place:
CS8618
: Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.Disclaimer: I am just a user of the library and not associated with the project nor its author/maintainer.
Not a bug.
It's the default for the ObjectCreationHandling setting in action. It's a bit unfortunate that this particular behavior has been chosen the default behavior, because it (unsurprisingly) catches quite a few users by surprise, but that choice had been made quite long ago, and with so many software projects relying on Newtonsoft.Json it is rather unlikely that a default setting will change... :(
In your case, both the FirstContained
and DifferentValue
properties are initialized with the same Contained.Empty
instance. And when Newtonsoft.Json deserializes the json objects for FirstContained
and DifferentValue
, it uses the assigned Contained
instance(s) to assign the value for the DifferentValue
property to it.
In other words, you see the same value for result.FirstContained.DifferentValue
and result.SecondContained.DifferentValue
because result.FirstContained
and result.SecondContained
refer to the same Contained.Empty
instance, and Newtonsoft.Json is reusing (populating) this Contained.Empty
instance instead of creating and assigning new Contained
instances to the FirstContained/SecondContained properties. This means, not only did you see a result you didn't expect, but the Contained.Empty
instance itself got modified by the deserializer, too.
To instruct Newtonsoft.Json to not reuse object instances but replace existing object instances with new ones, either set the [JsonProperty]
attribute's ObjectCreationHandling
property to ObjectCreationHandling.Replace
. Or, if this setting should affect the entire deserialization job, set the ObjectCreationHandling
property in an JsonSerializerSettings
instance and pass this JsonSerializerSettings instance to the (de)serializer.
P.S.: It is probably a good idea to spend a little time studying the default values used for the serialization settings used by the (de)serializer. Because there might be other default settings (and thus default behavior) of Newtonsoft.Json that you might or might not intuitively expect...
Destination types
Source JSON
Expected behavior
result.FirstContained.DifferentValue
differs fromresult.SecondContained.DifferentValue
Actual behavior
DifferentValue
always has the value which last occured in the input JSONSteps to reproduce
Workaround
Do not assign a default-value to objects (remove the
= Contained.Empty;
).Thank you for looking into this.