A simple middleware which adds a dummy cookie to the response

DummyCookieMiddleware.cs

public class DummyCookieMiddleware
{
    private readonly RequestDelegate _next;

    public DummyCookieMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public Task Invoke(HttpContext context)
    {
        // Check if cookie is already present
        var dummyCookieValue = context.Request.Cookies["DummyCookie"];
        var isValidDummyCookieValue = Guid.TryParse(dummyCookieValue, out Guid result);

        // If not present then add new value
        if(!isValidDummyCookieValue) {
            context.Response.Cookies.Append("DummyCookie", Guid.NewGuid().ToString());
        }

        // handover request to next delegate in pipeline
        return _next(context);
    }
}