Generate swagger.json from code with Swashbuckle V5

Question

I was using Swashbuckle AspNetCore v4.x.x and I upgrade to the v5.1.x.x. But the code I used in not working anymore, because of the lack of the class "SwaggerContractResolver".

The goal I attempt to is to generate the swagger.json in code of my RESTfull API :

public static string GenerateSwagger(this IWebHost webhost, string docName, string basePath)
{
    var sw = (ISwaggerProvider)webhost.Services.GetService(typeof(ISwaggerProvider));
    var doc = sw.GetSwagger(docName, null, basePath);

    var json = JsonConvert.SerializeObject(
        doc,
        Formatting.Indented,
        new JsonSerializerSettings
        {
            NullValueHandling = NullValueHandling.Ignore,
            ContractResolver = new SwaggerContractResolver(new JsonSerializerSettings())
        }
    );

    return json;
}

string json = GenerateSwagger(webhost, docName, url);
string path = Path.Combine(path, docName);
File.WriteAllText(path + ".json", json);

How can I do to do this working like the v4 but with the new version of Swashbuckle AspnetCore ?

Answer 1

With Swashbuckle V5, you can use .NET Core CLI to generate the swagger contract :

https://github.com/domaindrivendev/Swashbuckle.AspNetCore#swashbuckleaspnetcorecli

But this work only with .NET Core API. For .NET Framework, you can use this method :

public static string GenerateSwagger(this IWebHost webhost, string docName, string basePath)
{
    var sw = webhost.Services.GetRequiredService<ISwaggerProvider>();
    var doc = sw.GetSwagger(docName, null, basePath);

    using (var streamWriter = new StringWriter())
    {
        var writer = new OpenApiJsonWriter(streamWriter);
        doc.SerializeAsV3(writer);
        return streamWriter.ToString();
    }
}

You can witch OpenApiJsonWriter to OpenApiYamlWriter if you want YAML swagger contract.

You can switch SerializeAsV3 to SerializeAsV2 if you want V2 swagger contract.