async-moq2.cs

[Fact]
public void ProductRatingShouldNotNull()
{
    //Arrange
    var dbServiceMock = new Mock<IDbService>();
    dbServiceMock.Setup(x => x.GetRatingDataAsync(It.IsAny<object>()))
    .ReturnsAsync(() => {return List<RatingDto>();});
    var creditCardServices = new creditCardServices(dbServiceMock);
    //Act
    var sut = creditCardServices.GetProductAverageRating();

    //Assert
    sut.Should().NotBeNull();
}