`JsonIncludeAttribute` should override global `JsonSerializerOptions.IgnoreReadOnlyProperties` configuration.

[konrad-jamrozik]

Description

Expected behavior: If a read-only property has [JsonInclude] attribute, it should get serialized via JsonSerializer.Serialize even if following serialization options are used:

new JsonSerializerOptions { IgnoreReadOnlyProperties = true })

but this is not the case.

Actual behavior: the property is ignored by serialization.

Note that [JsonIgnore] will correctly override options that have IgnoreReadOnlyProperties = false and ignore a property. Hence I would expect an analogous "mirrored" behavior from [JsonInclude].

As a side note, I was unable to find any documentation explaining the precedence of attributes vs serializer options.

Reproduction Steps

Given in this gist:

https://gist.github.com/konrad-jamrozik/721a9c7624560fae0d1582353ef0708e

To repro, run JsonIncludeReproTests.JsonIgnoreOverridesOptionsButJsonIncludeDoesNot

Expected behavior

See the description above.

Actual behavior

See the description above.

Regression?

I don't know.

Known Workarounds

None

Configuration

.NET 8 preview. Details in the gist:

https://gist.github.com/konrad-jamrozik/721a9c7624560fae0d1582353ef0708e

Other information

No response

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Issue Details

---

Description

Expected behavior: If a read-only property has [JsonInclude] attribute, it should get serialized via JsonSerializer.Serialize even if following serialization options are used:

new JsonSerializerOptions { IgnoreReadOnlyProperties = false })

but this is not the case.

Actual behavior: the property is ignored by serialization.

Note that [JsonIgnore] will correctly override options that have IgnoreReadOnlyProperties = true and ignore a property. Hence I would expected analogous "mirrored" behavior from [JsonInclude].

Reproduction Steps

Given in this gist:

https://gist.github.com/konrad-jamrozik/721a9c7624560fae0d1582353ef0708e

Expected behavior

See description above.

Actual behavior

See description above.

Regression?

I don't know.

Known Workarounds

None

Configuration

.NET 8 preview. Details in the gist:

https://gist.github.com/konrad-jamrozik/721a9c7624560fae0d1582353ef0708e

Other information

No response

Author:	konrad-jamrozik
Assignees:	-
Labels:	area-System.Text.Json
Milestone:	-

[eiriktsarpalis]

It's something we could consider rectifying.

[konrad-jamrozik]

@eiriktsarpalis probably it should also override JsonSerializerOptions.IgnoreReadOnlyFields (if it already doesn't).

[HaraldMuehlhoffCC]

Just ran into the same problem; a setter (private or init will do) has to be defined ... otherwise [JsonInclude] is ignored.
This makes IgnoreReadOnlyProperties = true unusable in our use case as adding setters just for this would change the expressed intent; also very many changes would be required because of our very large codebase.