Properties of custom collections are not serialized with JSON serialization

[christiannagel]

Using JSON serialization (System.Text.Json) of custom collections, it would help adding documentation that the state of collections in addition to the collection is not serialized (e.g. properties of the custom collection).

The documentation at https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-supported-collection-types?pivots=dotnet-5-0 has this information:

System.Text.Json.JsonSerializer supports a collection type for serialization if it:

• Derives from IEnumerable.
• Contains elements that are serializable.

The serializer calls the GetEnumerator() method, and writes the elements.

Here, it would be helpful adding this information:

Properties or fields of custom collections are not serialized.

Maybe this information should be added here as well (or only here):

https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-supported-collection-types?pivots=dotnet-5-0#custom-collections

This behavior is described here (along with a project showing this): dotnet/runtime#46920

Target framework

• [5.0] .NET
• .NET Core
• .NET Framework
• .NET Standard

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Document Details

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• ID: 4a705da7-7165-2d5f-81d1-fdbef196786c
• Version Independent ID: 2f470a1c-8c81-2d26-3cad-92491229db15
• Content: Supported collection types in System.Text.Json
• Content Source: docs/standard/serialization/system-text-json-supported-collection-types.md
• Product: dotnet-fundamentals
• GitHub Login: @tdykstra
• Microsoft Alias: tdykstra

[tdykstra]

There's a request for more info in the runtime repo issue: dotnet/runtime#46920 (comment)

[no-response]

This issue has been automatically closed due to no response from the original author. Please feel free to reopen it if you have more information that can help us investigate the issue further.