Configure custom database initializer in app.config - entity-framework

Question

We have a custom initializer that does not change the database schema in any way; all it does is seed some data.
I've been asked to come up with a custom initializer that will always drop the database and then populate it with the same seed data (this will be used only in our database test projects).
I have written this initializer:
public class DropAndSeedDbInitializer<TContext, TSeedDataInitializer> : IDatabaseInitializer<TContext>
where TContext : DbContext
where TSeedDataInitializer : IDatabaseInitializer<TContext>, new()
{
private readonly DropCreateDatabaseAlways<TContext> _dbInitializer;
private readonly IDatabaseInitializer<TContext> _seedDataInitializer;
public DropAndSeedDbInitializer()
{
_dbInitializer = new DropCreateDatabaseAlways<TContext>();
_seedDataInitializer = Activator.CreateInstance<TSeedDataInitializer>();
}
public void InitializeDatabase(TContext context)
{
context.Database.ExecuteSqlCommand(TransactionalBehavior.DoNotEnsureTransaction
, string.Format("ALTER DATABASE [{0}] SET SINGLE_USER WITH ROLLBACK IMMEDIATE", context.Database.Connection.Database));
_dbInitializer.InitializeDatabase(context);
_seedDataInitializer.InitializeDatabase(context);
}
}
It works fine when I call
LicenceContext context = new LicenceContext();
Database.SetInitializer(new DropAndSeedDbInitializer<LicenceContext, TestSeedDataInitializer>());
context.Database.Initialize(true);
Then I decided to configure it in app.config like so:
<context type="Foo.LicenceContext, MyAssembly">
<databaseInitializer
type="Foo.DropAndSeedDbInitializer`2[[Foo.LicenceContext, MyAssembly], Foo.TestSeedDataInitializer, MyAssembly]], MyAssembly" />
</context>
and I removed this code:
Database.SetInitializer(new DropAndSeedDbInitializer<LicenceContext, TestSeedDataInitializer>());
context.Database.Initialize(true);
But then I get this error the first time I try to access my context:
Failed to set database initializer of type 'Foo.DropAndSeedDbInitializer`2[[Foo.LicenceContext, MyAssembly], Foo.TestSeedDataInitializer, MyAssembly]], MyAssembly' for DbContext type 'Foo.LicenceContext, MyAssembly' specified in the application configuration. See inner exception for details.
The inner exception is:
Exception of type 'System.ArgumentException' was thrown.
Parameter name: typeName#149
at System.Data.Entity.Internal.InitializerConfig.TryGetInitializer(Type requiredContextType, String contextTypeName, String initializerTypeName, Boolean isDisabled, Func`1 initializerArgs, Func`3 exceptionMessage)
at System.Data.Entity.Internal.InitializerConfig.<>c__DisplayClass6.<TryGetInitializerFromEntityFrameworkSection>b__1(ContextElement e)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
at System.Data.Entity.Internal.InitializerConfig.TryGetInitializerFromEntityFrameworkSection(Type contextType)
at System.Data.Entity.Internal.InitializerConfig.TryGetInitializer(Type contextType)
at System.Data.Entity.Infrastructure.DependencyResolution.AppConfigDependencyResolver.GetServiceFactory(Type type, String name)
at System.Data.Entity.Infrastructure.DependencyResolution.AppConfigDependencyResolver.<>c__DisplayClass1.<GetService>b__0(Tuple`2 t)
at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
at System.Data.Entity.Infrastructure.DependencyResolution.AppConfigDependencyResolver.GetService(Type type, Object key)
at System.Data.Entity.Infrastructure.DependencyResolution.ResolverChain.<>c__DisplayClass3.<GetService>b__0(IDbDependencyResolver r)
at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
Then I created a class which inherits from DropAndSeedDbInitializer like so:
public class DummyInitializer : DropAndSeedDbInitializer<LicenceContext, TestSeedDataInitializer>
{
}
And I configured it in app.config like so:
<context type="Foo.LicenceContext, MyAssembly">
<databaseInitializer
type="Foo.DummyInitializer, MyAssembly" />
</context>
And then the DropAndSeedDbInitalizer ran and I could access my context without any problems.
So my question is: should I be able to configure this custom initializer in app.config? If I should, what am I doing wrong?
Thanks,
David