StackOverflow Exception on circular reference

[Frankyfrankly]

Here is a code sample to reproduce the issue:

    public class Function1
    {
        private const string ContentType = "application/json";
        public List<Book> Lib { get; set; } = new List<Book>();

        [FunctionName(nameof(AddBook))]
        [OpenApiOperation(operationId: nameof(AddBook), Visibility = OpenApiVisibilityType.Important)]
        [OpenApiRequestBody(contentType: ContentType, bodyType: typeof(Book), Required = true)]
        [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: ContentType, bodyType: typeof(List<Book>))]
        public IActionResult AddBook([HttpTrigger(AuthorizationLevel.Function, "post", Route = null)][FromBody] Book req, ILogger log)
        {
            Lib.Add(req);
            return new OkObjectResult(Lib);
        }
    }

    public class Book
    {
        public string Name { get; set; }
        public DateTime PublicationDate { get; set; }
        public Author Author { get; set; }
    }

    public class Author
    {
        public string Name { get; set; }
        public List<Book> Books { get; set; }
    }

It seems like recursion happens in Visit method of ObjectTypeVisitor class.

The same can be reproduced in Microsoft.Azure.WebJobs.Extensions.OpenApi.FunctionApp.V3IoC project by adding a new class Owner:

       public class Owner
    {
        public string Name { get; set; }
        public List<Pet> Pets { get; set; }
    }

And introducing new property "public Owner Owner { get; set; }" in Pet class

[justinyoo]

@Frankyfrankly Thanks for the issue. I looked at the issue, but if you change the models' structure it will solve your issue:

public class Book
{
    ...
    public string AuthorId { get; set; }
}

public class Author
{
    ...
    public List<Book> Books { get; set; }
}

To me, the circular reference issue is about how data structure looks like, rather than the issue of this extension. If you still want to keep the Author in your Book class, I would recommend adding the [OpenApiIgnore()] decorator on top of it like:

public class Book
{
    ...
    public string AuthorId { get; set; }

    [OpenApiIgnore()]
    public Author Author { get; set; }
}

By doing so, you will avoid the circular reference issue.

[justinyoo]

@Frankyfrankly I'll close the issue for now. If you'd like to discuss more on this, please open a new issue.