getting system.nullreferenceexcepection

This is the test project

public class UnitTest1
{
//private ProductRepository repository;
//private ProductRepository productDateRepositor;
private IProductRepository productRepository;
private IProductDateRepository productDateRepository;
public ProductController productController;
List list;
[TestInitialize]
public void setUpController()
{
//repository = new ProductRepository();
//productDateRepositor = new ProductRepository();
productController = new ProductController(productRepository, productDateRepository);
list = new List()
{
new ProductModel(){Id=1,tickersymbol = "AAP", Price = 11100 ,Date=DateTime.Parse("12/25/2018") },
new ProductModel(){Id=2,tickersymbol = "DAL", Price = 22200,Date=DateTime.Parse("11/27/2018")},
new ProductModel(){Id=3,tickersymbol = "GE", Price = 33300,Date=DateTime.Parse("12/26/2018")},
new ProductModel(){Id=4,tickersymbol = "AMZN", Price = 44400,Date=DateTime.Parse("11/27/2018")},
new ProductModel(){Id=5,tickersymbol = "FNB", Price = 55500,Date=DateTime.Parse("12/28/2018")},
};
}
[TestMethod]
public void Index()
{
//Arrange
var controller = productController;
//Act
var result = controller.Index("AAP") as ViewResult;
var tickerdetails = (ProductModel)result.ViewData.Model;
//Assert
Assert.AreEqual("AAP",tickerdetails.tickersymbol );
}

While running this I am getting Message: Test method UnitTestProject2.UnitTest1.Index threw exception:

System.NullReferenceException: Object reference not set to an instance of an object.

This is the Repository

public class ProductRepository : IProductRepository
{
private List _products;
public ProductRepository()
{
_products = new List()
{
// Add products for the Demonstration
new ProductModel(){Id=1,tickersymbol = "AAP", Price = 11100 ,Date=DateTime.Parse("12/25/2018") },
new ProductModel(){Id=2,tickersymbol = "DAL", Price = 22200,Date=DateTime.Parse("11/27/2018")},
new ProductModel(){Id=3,tickersymbol = "GE", Price = 33300,Date=DateTime.Parse("12/26/2018")},
new ProductModel(){Id=4,tickersymbol = "AMZN", Price = 44400,Date=DateTime.Parse("11/27/2018")},
new ProductModel(){Id=5,tickersymbol = "FNB", Price = 55500,Date=DateTime.Parse("12/28/2018")},
};
}
public IEnumerable GetPrice(string Name, DateTime? Date)
{
if (Date != null && Name!="")
{
var product = _products.Where(x => x.tickersymbol.StartsWith(Name) && x.Date == Date).ToList();
return product;
}
else
{
return _products.ToList();
}
}
ProductModel IProductRepository.Get(int id)
{
return _products.Find(p => p.Id == id);
}
IEnumerable IProductRepository.GetAll(string Name)
{
if (Name != "")
{
var product = _products.Where(x => x.tickersymbol.StartsWith(Name) || Name == null).ToList();
return product;
}
else
{
return _products.ToList();
}
}
IEnumerable IProductRepository.GetAll()
{
return _products.ToList();
}
}
}

3 Replies

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Jayanth Reddy7y ago
Accepted answer
I got this exception when instead of creating an object I just created a reference.You can check for the same kind of mistake.Also i think when we forget to insert data into a table's column which was "Not null" we will get this kind of exception.
+2
Rajanikant Hawaldar7y ago
Hi Gitanjali, Please do debug, somewhere method or property is your using through object butobject null this is the issue. add try catch and take use of Exception Settings so that in which line your getting error it will show once error trigger

https://docs.microsoft.com/en-us/visualstudio/debugger/managing-exceptions-with-the-debugger?view=vs-2019
+1
Amit Gupta7y ago
You need to debug your project, as this exception occurred when some value is null and you want to access its properties.
+1