Misleading wording for serializer behavior description.

[voroninp]

Documentation says:

Non-public constructors, including parameterless constructors, are ignored by the serializer by default.

This creates an impression there exists a way to change the default behavior for non-public constructors. I'd completely remove by default.

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Document Details

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• ID: 93ca6bfd-1d1f-a53c-2cd0-fa87511d3cb5
• Version Independent ID: 3ffd812b-bddb-9a54-4e22-63e4c76fc5dd
• Content: Breaking change: Non-public, parameterless constructors not used for deserialization - .NET
• Content Source: docs/core/compatibility/serialization/5.0/non-public-parameterless-constructors-not-used-for-deserialization.md
• Product: dotnet-fundamentals
• GitHub Login: @gewarren
• Microsoft Alias: gewarren

[gewarren]

@layomia @tdykstra should "by default" be removed from the wording? I'm unsure if the use of a JsonConverter<T> allows the use of a non-public constructor.

Recommended action

- If you own the type and it's feasible, make the parameterless constructor public.
- Otherwise, implement a JsonConverter<T> for the type and control the deserialization behavior.

[tdykstra]

I'm unsure if the use of a JsonConverter allows the use of a non-public constructor.

Same here.

[gewarren]

Ping @layomia.

[layomia]

Yes @gewarren, a non-public constructor can be called from a JsonConverter<T> implementation if C# accessibility rules for that scenario allow it. We could explicitly state this in our recommendation.

For .NET 6.0, we are planning a way to support using non-public constructors as a first-class feature using JsonConstructorAttribute - dotnet/runtime#38327. Support for including non-public properties/fields with JsonIncludeAttribute is planned as well - dotnet/runtime#31511.

[douglasg14b]

@layomia The docs till says Public constructor annotated with JsonConstructorAttribute and makes no mention if a non-public constructor being able to be used.