use repository and unit of work in in unit testing code example

Example: use repository and unit of work in in unit testing

[TestMethod]
public void ProductService_Given_Product_Id_Should_Get_Product_Name() {
    //Arrange
    var productId = 1;
    var expected = "AAA";
    var product = new Product() { ProductName = expected, ProductID = productId };

    var productRepositoryMock = new Mock<IEntityRepository<Product>>();
    productRepositoryMock.Setup(m => m.GetByID(productId)).Returns(product).Verifiable();

    var unitOfWorkMock = new Mock<IUnitOfWork>();
    unitOfWorkMock.Setup(m => m.productRepository).Returns(productRepositoryMock.Object);

    IProductService sut = new ProductService(unitOfWorkMock.Object);
    //Act
    var actual = sut.GetProductName(productId);

    //Assert
    productRepositoryMock.Verify();//verify that GetByID was called based on setup.
    Assert.IsNotNull(actual);//assert that a result was returned
    Assert.AreEqual(expected, actual);//assert that actual result was as expected
}