I have read so much (dozens of posts) about one thing:
How to unit test business logic code that has Entity Framework code in it.
I have a WCF service with 3 layers :
- Service Layer
- Business Logic Layer
- Data Access Layer
My business logic uses the DbContext for all the database operations. All my entities are now POCOs (used to be ObjectContext, but I changed that).
I have read Ladislav Mrnka's answer here and here on the reasons why we should not mock \ fake the DbContext.
He said: "That is the reason why I believe that code dealing with context / Linq-to-entities should be covered with integration tests and work against the real database."
and: "Sure, your approach works in some cases but unit testing strategy must work in all cases - to make it work you must move EF and IQueryable completely from your tested method."
My question is - how do you achieve this ???
public class TaskManager
{
public void UpdateTaskStatus(
Guid loggedInUserId,
Guid clientId,
Guid taskId,
Guid chosenOptionId,
Boolean isTaskCompleted,
String notes,
Byte[] rowVersion
)
{
using (TransactionScope ts = new TransactionScope())
{
using (CloseDBEntities entities = new CloseDBEntities())
{
User currentUser = entities.Users.SingleOrDefault(us => us.Id == loggedInUserId);
if (currentUser == null)
throw new Exception("Logged user does not exist in the system.");
// Locate the task that is attached to this client
ClientTaskStatus taskStatus = entities.ClientTaskStatuses.SingleOrDefault(p => p.TaskId == taskId && p.Visit.ClientId == clientId);
if (taskStatus == null)
throw new Exception("Could not find this task for the client in the database.");
if (taskStatus.Visit.CustomerRepId.HasValue == false)
throw new Exception("No customer rep is assigned to the client yet.");
TaskOption option = entities.TaskOptions.SingleOrDefault(op => op.Id == optionId);
if (option == null)
throw new Exception("The chosen option was not found in the database.");
if (taskStatus.RowVersion != rowVersion)
throw new Exception("The task was updated by someone else. Please refresh the information and try again.");
taskStatus.ChosenOptionId = optionId;
taskStatus.IsCompleted = isTaskCompleted;
taskStatus.Notes = notes;
// Save changes to database
entities.SaveChanges();
}
// Complete the transaction scope
ts.Complete();
}
}
}
In the code attached there is a demonstration of a function from my business logic. The function has several 'trips' to the database. I don't understand how exactly I can strip the EF code from this function out to a separate assembly, so that I am able to unit test this function (by injecting some fake data instead of the EF data), and integrate test the assembly that contains the 'EF functions'.
Can Ladislav or anyone else help out?
[Edit]
Here is another example of code from my business logic, I don't understand how I can 'move the EF and IQueryable code' out from my tested method :
public List<UserDto> GetUsersByFilters(
String ssn,
List<Guid> orderIds,
List<MaritalStatusEnum> maritalStatuses,
String name,
int age
)
{
using (MyProjEntities entities = new MyProjEntities())
{
IQueryable<User> users = entities.Users;
// Filter By SSN (check if the user's ssn matches)
if (String.IsNullOrEmusy(ssn) == false)
users = users.Where(us => us.SSN == ssn);
// Filter By Orders (check fi the user has all the orders in the list)
if (orderIds != null)
users = users.Where(us => UserContainsAllOrders(us, orderIds));
// Filter By Marital Status (check if the user has a marital status that is in the filter list)
if (maritalStatuses != null)
users = users.Where(pt => maritalStatuses.Contains((MaritalStatusEnum)us.MaritalStatus));
// Filter By Name (check if the user's name matches)
if (String.IsNullOrEmusy(name) == false)
users = users.Where(us => us.name == name);
// Filter By Age (check if the user's age matches)
if (age > 0)
users = users.Where(us => us.Age == age);
return users.ToList();
}
}
private Boolean UserContainsAllOrders(User user, List<Guid> orderIds)
{
return orderIds.All(orderId => user.Orders.Any(order => order.Id == orderId));
}
