SwaggerUI 5.0.0 ignoring JsonProperty name

Question

I recently upgraded a ASP.NET Core API application to Swashbuckle/Swagger 5.0.0 with ASP.NET Core 3.1.

<PackageReference Include="Swashbuckle.AspNetCore" Version="5.0.0" />
<PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="5.0.0" />
<PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.0.0" />
<PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.0.0" />

However, upon doing so I have noticed that the Swagger UI is now ignoring the Newtonsoft/JSON.NET JsonProperty attribute names on DTO properties. For example:

[HttpGet("testget", Name = "testget")]
[ProducesResponseType(StatusCodes.Status200OK)]
public ActionResult<TestGetResponse> TestGet()
{
    var response = new TestGetResponse { MyName = "John" };

    return Ok(response);
}

public class TestGetResponse
{
    [JsonProperty("name")]
    public string MyName { get; set; }
}

Is outputting in Swagger UI as:

Code 200: Example Value

Model
{
  "myName": "string"
}

Instead of Model property name name.

For Swagger in Startup.cs ConfigureServices I currently have:

services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo
    {
        Version = "v1",
        Title = "My API",
    });

    c.IncludeXmlComments(Path.Combine(AppContext.BaseDirectory, $"{Assembly.GetExecutingAssembly().GetName().Name}.xml"));
});

And for Swagger in Startup.cs Configure I currently have:

app.UseSwagger();

app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API");
    c.RoutePrefix = "swagger";
});

I am aware that if I use the System.Text.Json attribute JsonPropertyName instead this will be fixed however I need to stick with the original attributes for now.

Is there a setting in Start.cs to tell SwaggerUI to use the Newtonsoft JsonProperty attribute or is there something I need to change at the ASP.NET Core level of configuration?

Answer 1

It would appear that full support for NewtonSoft JSON.net from version 5.0.0 of Swashbuckle/Swagger is provided through a separate package.

To get this working:

1) Install the nuget package Swashbuckle.AspNetCore.Newtonsoft version 5.0.0+

2) In Startup.ConfigureServices() make a call for the support:

services.AddSwaggerGenNewtonsoftSupport();

Further info can be found here.