Unit Test Method that uses Linq EF 6 - entity-framework

I'm using EF 6 and MVC 5. I have a method callded MaxScore, see below. I've tested it and it works within my project. I'm new to unit testing so I decided to try it out against this method. When I debug the test I get an error, "Object reference not set to instance of an object". The error points to line 6 in the method below. Any ideas?
Here is my method:
private HandicapSystemContext db = new HandicapSystemContext();
public int MaxScore(double handicap)
{
int _maxScore = 0;
_maxScore = db.AdjustedGrossScores.FirstOrDefault(x => x.MinimiumHandicap <= handicap && x.MaximumHandicap >= handicap).Score;
return _maxScore;
}
Here is my unit test method:
[TestMethod]
public void TestMaxScore()
{
int _maxScore = 0;
Calculation hc = new Calculation();
_maxScore = hc.MaxScore(10);
Assert.AreEqual(_maxScore, 7);
}

To fix the issue, I had to add Entity Framewwork (Using NuGet) to the Test Project. I added a connectionstring to the app.config file. Since I'm using Code First and dropping and regenerating the database on model changes, I had to copy the localDB files to the /bin/Debug/ folder. I will have to recopy the database every time the database changes until I get to a solid state and switch over to a Sql Server database.

Related

Using EF with stored procedure and getting error as New transaction is not allowed because there are other threads running in the session

In Entity framework, I have implemented generic repository and unit of work pattern.
Below is related stuff from unit of work:
public IRepository<TEntity, TKey> GetRepository<TEntity, TKey>() where TEntity : class
{
if (_repositories == null)
{
_repositories = new Dictionary<string, object>();
}
string key = String.Format("{0}|{1}", typeof(TEntity).Name, typeof(TKey).Name);
if (_repositories.ContainsKey(key))
{
return (IRepository<TEntity, TKey>)_repositories[key];
}
Type repositoryType = typeof(Repository<TEntity, TKey>);
_repositories.Add(key, Activator.CreateInstance(repositoryType, _dataContext));
return (IRepository<TEntity, TKey>)_repositories[key];
}
From Manager layer, entity framework is call as below:
IRepository<tablenameEntity int> _tableEntityRepository = _unitOfWork.GetRepository<tablenameEntity, int>();
Error is as follow:
An error occurred while starting a transaction on the provider connection. See the inner exception for details.
{"New transaction is not allowed because there are other threads running in the session."}.
Actually, I just did as below,
remove stored procedure and function from model browser and added procedure and function again.
run custom tool on edmx file.
It just work out.
I am not sure, what was the issue. did that before also, but it was not work.. now, it works and not produce after that.
Thanks

Entity Framework MigrateDatabaseToLatestVersion giving error

I am attempting to use Entity Framework code based migrations with my web site. I currently have a solution with multiple projects in it. There is a Web API project which I want to initialize the database and another project called the DataLayer project. I have enabled migrations in the DataLayer project and created an initial migration that I am hoping will be used to create the database if it does not exist.
Here is the configuration I got when I enabled migrations
public sealed class Configuration : DbMigrationsConfiguration<Harris.ResidentPortal.DataLayer.ResidentPortalContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(Harris.ResidentPortal.DataLayer.ResidentPortalContext context)
{
// This method will be called after migrating to the latest version.
// You can use the DbSet<T>.AddOrUpdate() helper extension method
// to avoid creating duplicate seed data. E.g.
//
// context.People.AddOrUpdate(
// p => p.FullName,
// new Person { FullName = "Andrew Peters" },
// new Person { FullName = "Brice Lambson" },
// new Person { FullName = "Rowan Miller" }
// );
//
}
}
The only change I made to this after it was created was to change it from internal to public so the WebAPI could see it and use it in it's databaseinitializer. Below is the code in the code in the Application_Start that I am using to try to initialize the database
Database.SetInitializer(new MigrateDatabaseToLatestVersion<ResidentPortalContext, Configuration>());
new ResidentPortalUnitOfWork().Context.Users.ToList();
If I run this whether or not a database exists I get the following error
Directory lookup for the file "C:\Users\Dave\Documents\Visual Studio 2012\Projects\ResidentPortal\Harris.ResidentPortal.WebApi\App_Data\Harris.ResidentPortal.DataLayer.ResidentPortalContext.mdf" failed with the operating system error 2(The system cannot find the file specified.).
CREATE DATABASE failed. Some file names listed could not be created. Check related errors.
It seems like it is looking in the totally wrong place for the database. It seems to have something to do with this particular way I am initializing the database because if I change the code to the following.
Database.SetInitializer(new DropCreateDatabaseAlways<ResidentPortalContext>());
new ResidentPortalUnitOfWork().Context.Users.ToList();
The database will get correctly created where it needs to go.
I am at a loss for what is causing it. Could it be that I need to add something else to the configuration class or does it have to do with the fact that all my migration information is in the DataLayer project but I am calling this from the WebAPI project?
I have figured out how to create a dynamic connection string for this process. You need to first add this line into your EntityFramework entry on Web or App.Config instead of the line that gets put there by default.
<defaultConnectionFactory type="<Namespace>.<ConnectionStringFacotry>, <Assembly>"/>
This tells the program you have your own factory that will return a DbConnection. Below is the code I used to make my own factory. Part of this is a hack to get by the fact that a bunch of programmers work on the same set of code but some of us use SQL Express while others use full blown SQL Server. But this will give you an example to go by for what you need.
public sealed class ResidentPortalConnectionStringFactory: IDbConnectionFactory
{
public DbConnection CreateConnection(string nameOrConnectionString)
{
SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(ConfigurationManager.ConnectionStrings["PortalDatabase"].ConnectionString);
//save off the original catalog
string originalCatalog = builder.InitialCatalog;
//we're going to connect to the master db in case the database doesn't exist yet
builder.InitialCatalog = "master";
string masterConnectionString = builder.ToString();
//attempt to connect to the master db on the source specified in the config file
using (SqlConnection conn = new SqlConnection(masterConnectionString))
{
try
{
conn.Open();
}
catch
{
//if we can't connect, then append on \SQLEXPRESS to the data source
builder.DataSource = builder.DataSource + "\\SQLEXPRESS";
}
finally
{
conn.Close();
}
}
//set the connection string back to the original database instead of the master db
builder.InitialCatalog = originalCatalog;
DbConnection temp = SqlClientFactory.Instance.CreateConnection();
temp.ConnectionString = builder.ToString();
return temp;
}
}
Once I did that I coudl run this code in my Global.asax with no issues
Database.SetInitializer(new MigrateDatabaseToLatestVersion<ResidentPortalContext, Configuration>());
using (ResidentPortalUnitOfWork temp = new ResidentPortalUnitOfWork())
{
temp.Context.Database.Initialize(true);
}

Calling stored procedure from Entity Framework 3.5

I"m using VS 2010 & EF 3.5. I've imported a stored procedure which returns a list of guids using the Function Import feature. How do I invoke it in my code? After instantiating the dbcontext, intellisense doesn't display the procedure I've imported. I know it's pretty easy in EF 4.0 but I'm stuck with EF 3.5 for this project. Any ideas on how get around this other than doing it the old-fashioned way?
I don't think EF versions prior to 4 can use imported stored procedures that don't return entities. That is, your stored procedure must return a complete entity object in order for EF to use it. Since your procedure only returns a list of GUIDs, EF doesn't know how to use it.
You can put this in your partial data-context class to call the procedure:
public IEnumerable<Guid> GetMyGUIDs()
{
if (this.Connection.State != System.Data.ConnectionState.Open)
this.Connection.Open();
var command = new System.Data.EntityClient.EntityCommand
{
CommandType = System.Data.CommandType.StoredProcedure,
CommandText = #"YourContext.YourProcedureName",
Connection = (System.Data.EntityClient.EntityConnection)this.Connection
};
var list = new List<Guid>();
using (var reader = command.ExecuteReader())
{
// get GUID values from the reader here,
// and put them in the list
reader.Close();
}
return list;
}

Unable to persist Entities to SQL CE using entity framework

I am stating out with entity framework. I have created my ADO.NET Entity Model and mapped the entities to a local SQL CE database file (all done via the wizards). I have created a unit test to test the data access and see how things work. The test executes fine and without any exceptions. However, no new row is generated in the database. Please Help!!!
public void TestCreateRelationshipType()
{
using (var c = new TenderModelEntities())
{
IList<RelationshipType> types = c.RelationshipTypes.ToList<RelationshipType>();
int num1 = types.Count();
RelationshipType type = new RelationshipType();
type.Description = "New Client";
c.AddToRelationshipTypes(type);
c.SaveChanges();
IList<RelationshipType> types2 = c.RelationshipTypes.ToList<RelationshipType>();
int num2 = types2.Count();
Assert.AreEqual(num1 + 1, num2);
}
}
New row is added to the database because you call the SaveChanges() function. When you call this on your datacontext, the changes are passed on to the database.
If you don't want to make any changes to the database, just comment out this section like below
// c.SaveChanges();

MSTest with Moq - DAL setup

I'm new to Moq, and just started on a project that's already in development. I'm responsible for setting up unit testing. There's a custom class for the DatabaseFactory that uses EnterpriseLibrary and looks like this:
public Database CreateCommonDatabase()
{
return CreateDatabaseInstance(string.Empty);
}
private static Database CreateDatabaseInstance(string foo)
{
var database = clientCode == string.Empty
? DatabaseFactory.CreateDatabase("COMMON")
: new OracleDatabase(new ClientConnections().GetConnectionString(foo)));
return database;
}
Now, here's where that gets used (ResultData is another class of the type DataSet):
public ResultData GetNotifications(string foo, string foo2, Database database)
{
var errMsg = string.Empty;
var retval = 0;
var ds = new DataSet();
var sqlClause =
#"[Some SELECT statement here that uses foo]";
DbCommand cm = database.GetSqlStringCommand(sqlClause);
cm.CommandType = CommandType.Text;
// Add Parameters
if (userSeq != string.Empty)
{
database.AddInParameter(cm, ":foo2", DbType.String, foo2);
}
try
{
ds = database.ExecuteDataSet(cm);
}
catch (Exception ex)
{
retval = -99;
errMsg = ex.Message;
}
return new ResultData(ds, retval, errMsg);
}
Now, originally, the Database wasn't passed in as a parameter, but the method was creating a new instance of the DatabaseFactory using the CreateCommonDatabase method, and using it from there. However, that leaves the class untestable because I can't keep it from actually hitting the database. So, I went with Dependency Injection, and pass the Database in.
Now, I'm stuck, because there's no way to mock Database in order to test GetNotifications. I'm wondering if I'm overly complicating things, or if I'm missing something. Am I doing this the right way, or should I be rethinking how I've got this set up?
Edit to add more info*****
I really don't want to test the database. I want the Data.Notifications class (above) to return an instance of ResultData, but that's all I really want to test. If I go a level up, to the Business layer, I have this:
public DataSet GetNotifications(string foo, string foo1, out int returnValue, out string errorMessage, Database database)
{
ResultData rd = new data.Notifications().GetNotifications(foo, foo1, database);
returnValue = rd.ResultValue;
errorMessage = rd.ErrorMessage;
return rd.DataReturned;
}
So, originally, the database wasn't passed in, it was the Data.Notifications class that created it - but then again, if I left it that way, I couldn't help but hit the database to test this Business layer object. I modified all of the code to pass the Database in (which gets created a the web's Base page), but now I'm just not certain what to do next. I thought I was one unit test away from having this resolved, but apparently, either I'm wrong or I've got a mental roadblock to the right path.
You should be able to create a mock Database object if the methods in it are virtual. If they are not, then you have a little bit of a problem.
I don't know what type "Database" is, but you have a few options.
If you own the source code to Database, I would recommend extracting an interface IDatabase, rather than dealing with a Database class type. This will eliminate some complexity and give you something extremely testable.
If you don't have access to the Database class, you can always solve this with another layer of abstraction. Many people in this case use a Repository pattern that wraps the data access layer. Generally speaking in this case, most people leave testing Respository classes to integration tests (tests without any isolation), rather than unit tests.
Here's how you'd setup your test using option #1:
[TestMethod]
public void GetNotifications_PassedNullFoo_ReturnsData()
{
//Arrange
Mock<IDatabase> mockDB = new Mock<IDatabase>();
mockDB.Setup(db => db.ExecuteDataSet()).Returns(new DataSet() ... );
//Act
FooClass target = new fooClass();
var result = target.GetNotifications(null, "Foo2", mockDB.Object);
//Assert
Assert.IsTrue(result.DataSet.Rows.Count > 0);
}
My dataset code is a little rusty, but hopefully this gives you the general idea.
Based on the code you've given, I would think you would want to talk to the database, and not a mocked version.
The reason is that your GetNotifications code contains DB-specific instructions, and you'll want those to pass validation at the DB Engine level. So just pass in a Database that is connected to your test DB instance.
If you took the testing abstraction to a higher level, where you built unit tests for the database call and a version of this test that used a mocked database, you'd still have to run integration tests, which ends up being triple the work for the same amount of code coverage. In my opinion, it's far more efficient to do an integration test at tier borders you control then to write unit tests for both sides of the contract and integration tests.