System.Text.Json -> Deserialize Null to Integer Property

[jogibear9988]

Description

We hav the following Code:

    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public virtual int OrderIndex { get; set; }

But it throws a exception when we deserialize a "null" value to a Object with this et

Reproduction Steps

see code above

Expected behavior

should use default value for int

Actual behavior

does not work

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

[ghost]

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Issue Details

---

Description

We hav the following Code:

    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public virtual int OrderIndex { get; set; }

But it throws a exception when we deserialize a "null" value to a Object with this et

Reproduction Steps

see code above

Expected behavior

should use default value for int

Actual behavior

does not work

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

Author:	jogibear9988
Assignees:	-
Labels:	area-System.Text.Json
Milestone:	-

[layomia]

JsonIgnoreCondition.WhenWritingNull is only applied to writing/serialization, not deserialization. There's a proposal to extend the enum to include something like JsonIgnoreCondition.WhenReadingNull - #66490. I'll close this as part of that larger issue.

The custom serialization contracts features provides a predicate JsonPropertyInfo.ShouldSerialize to determine whether a property's value should be serialized. I believe the same was considered for deserialization. It would be helpful for scenarios like this. cc @krwq, @eiriktsarpalis.

[krwq]

could you simply customize JsonPropertyInfo so that Set ignores null value and does custom behavior?

[jogibear9988]

could you simply customize JsonPropertyInfo so that Set ignores null value and does custom behavior?

we don't use the source code generators at the moment.

[krwq]

@jogibear9988 that's a contract customization feature we're shipping in 7.0 it works with both code-gen and reflection, it should be in pre-release nuget package 7.0.0-preview.6 or higher

JsonSerializerOptions options =...;
options.TypeInfoResolver = new DefaultJsonTypeInfoResolver()
{
  Modifiers = { typeInfo => { if (typeInfo.Type == typeof(...)) { /* typeInfo.Properties modification here */ } } }
};

// then: JsonSerializer.Deserialize<...>(json, options);