Mock IRabbitMQFactory using xunit

Question

How to mock the constructor using xunit if I have the following service :

    public class MyService : IMyService
    {
        private readonly IPublisher _publisher;

        public MyService (IRabbitMQFactory mqFactory)
        {
            _publisher = mqFactory.GetScopedPublisher(
                    new Tools.RabbitMq.Nuget.Parameters.ExchangeParameters
                    (
                        name: "MyService",
                        type: ERabbitMqExchangeType.DIRECT
                    ));
        }

        // ...
    }

I would like create UT for a service that publish message with RabbitMqFactory.