SwaggerDefaultValues.cs

namespace All;
using Microsoft.AspNetCore.Mvc.ApiExplorer;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.OpenApi.Models;
using Swashbuckle.AspNetCore.SwaggerGen;
using System.Text.Json;
/// <summary>
/// Represents the OpenAPI/Swashbuckle operation filter used to document information provided, but not used.
/// </summary>
/// <remarks>This <see cref="IOperationFilter"/> is only required due to bugs in the <see cref="SwaggerGenerator"/>.
/// Once they are fixed and published, this class can be removed.</remarks>
public class SwaggerDefaultValues : IOperationFilter
{
    /// <inheritdoc />
    public void Apply(OpenApiOperation operation, OperationFilterContext context)
    {
        var apiDescription = context.ApiDescription;
        operation.Deprecated |= apiDescription.IsDeprecated();
        // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/1752#issue-663991077
        foreach (var responseType in context.ApiDescription.SupportedResponseTypes)
        {
            // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/blob/b7cf75e7905050305b115dd96640ddd6e74c7ac9/src/Swashbuckle.AspNetCore.SwaggerGen/SwaggerGenerator/SwaggerGenerator.cs#L383-L387
            var responseKey = responseType.IsDefaultResponse ? "default" : responseType.StatusCode.ToString();
            var response = operation.Responses[responseKey];
            foreach (var contentType in response.Content.Keys)
            {
                if (!responseType.ApiResponseFormats.Any(x => x.MediaType == contentType))
                {
                    response.Content.Remove(contentType);
                }
            }
        }
        if (operation.Parameters == null)
        {
            return;
        }
        // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/412
        // REF: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/pull/413
        foreach (var parameter in operation.Parameters)
        {
            var description = apiDescription.ParameterDescriptions.First(p => p.Name == parameter.Name);
            if (parameter.Description == null)
            {
                parameter.Description = description.ModelMetadata?.Description;
            }
            if (parameter.Schema.Default == null &&
                 description.DefaultValue != null &&
                 description.DefaultValue is not DBNull &&
                 description.ModelMetadata is ModelMetadata modelMetadata)
            {
                // REF: https://github.com/Microsoft/aspnet-api-versioning/issues/429#issuecomment-605402330
                var json = JsonSerializer.Serialize(description.DefaultValue, modelMetadata.ModelType);
                parameter.Schema.Default = OpenApiAnyFactory.CreateFromJson(json);
            }
            parameter.Required |= description.IsRequired;
        }
    }
}