public void test() { var repo = new Mock <IProductRepository>(); var mapper = new Mock <IMapper>(); repo.Setup(c => c.Add(It.IsAny <Product>())).Returns("Added"); mapper.Setup(c => c.Map <CreateProductRequest, Product>(It.IsAny <CreateProductRequest>())).Returns(new Product()); var handler = new CreateProductRequestHandler(repo.Object, mapper.Object); var result = handler.Handle(new CreateProductRequest(), new CancellationToken()).Result; helper.WriteLine(result); }