[Bug]: SystemTextJsonContentSerializer.GetFieldNameForProperty(PropertyInfo) does not use the provided JsonSerializerOptions

[othmane-kinane-nw]

Describe the bug 🐞

The value returned by SystemTextJsonContentSerializer.GetFieldNameForProperty(PropertyInfo) doesn't match the provided JsonSerializerOptions.PropertyNamingPolicy

Step to reproduce

using System.Reflection;
using System.Text.Json;
using Refit;
using Xunit;

public class SystemTextJsonContentSerializerTests
{
    private record CustomDto(string MyProperty);

    [Fact]
    public void field_name_should_match_the_provided_PropertyNamingPolicy()
    {
        JsonSerializerOptions jsonOptions = new()
        {
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        };
        SystemTextJsonContentSerializer contentSerializer = new(jsonOptions);
        PropertyInfo propertyInfo = typeof(CustomDto).GetProperty(nameof(CustomDto.MyProperty))!;
        string? fieldName = contentSerializer.GetFieldNameForProperty(propertyInfo);
        Assert.Equal("myProperty", fieldName);
    }
}

Reproduction repository

No response

Expected behavior

fieldName value should be myProperty instead of null.

Screenshots 🖼️

No response

IDE

No response

Operating system

No response

Version

No response

Device

No response

ReactiveUI Version

No response

Additional information ℹ️

No response

[othmane-kinane-nw]

If this is considered as a bug, the fix is to add the highlighted line here: https://github.com/reactiveui/refit/blob/main/Refit/SystemTextJsonContentSerializer.cs#L67

GitHub

refit/SystemTextJsonContentSerializer.cs at main · reactiveui/refit

The automatic type-safe REST library for .NET Core, Xamarin and .NET. Heavily inspired by Square's Retrofit library, Refit turns your REST API into a live interface. - refit/SystemTextJsonConte...

[glennawatson]

Addressed in #2154.

We went with opt-in naming presets rather than changing the default, because:

• GetFieldNameForProperty also feeds form-url-encoded and query-object key naming, so making it honour PropertyNamingPolicy by default would flip every existing form/query key from PascalCase to camelCase.
• The default options already use JsonNamingPolicy.CamelCase, so that change would hit everyone on defaults - a silent breaking change.

So instead you can now opt a whole client into one convention, applied consistently to query keys, form keys and JSON body:

RestService.For<IApi>(url, RefitSettings.SnakeCase());

• Presets: RefitSettings.CamelCase() / SnakeCase() / KebabCase().
• New SnakeCaseUrlParameterKeyFormatter / KebabCaseUrlParameterKeyFormatter for custom UrlParameterKeyFormatter setups.
• Default behaviour is unchanged; the new naming is fully opt-in.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.