public async Task OnGet_ReturnPaginatedList(decimal PriceFrom,
decimal PriceTo, string searchString)
{
//Arrange
var mockProductsRep = new Mock <IProductsRepository>();
mockProductsRep.Setup(_db => _db.GetAllProducts()).Returns(MockProducts.GetAllProductsTest()); //настрока: вызов нужного метода и передача данных
var pageModel = new CatalogModel(mockProductsRep.Object, new Mock <IMaterialsRepository>().Object, new Mock <IManufacturersRepostory>().Object);
//Act
var result = await pageModel.OnGetAsync(PriceFrom, PriceTo, SortState.NameAsc, null, null, 1, searchString);
//Assert
Assert.IsType <PaginatedList <Products> >(result);
}