Configuring default value with fluent API doesn't support enum value without explicitly casting to int

[EvAlex]

Suppose we have model class with property of enum type that should be mapped to INT column in database. The class looks as follows

public class Employee
{
    public int Id { get; set; }

    public OccupationType OccupationType { get; set; }
}

public enum OccupationType 
{
    Fulltime,
    Parttime,
    Freelance
}

Also we want to configure default value for that column with fluent API as follows:

builder.Entity<Employee>()
    .Property(e => e.OccupationType)
    .HasDefaultValue(OccupationType.Fulltime);

Everything looks fine. Let's generate migration:

dnx ef migrations add AddEmployees

Here's what we get:

System.NotSupportedException: Annotations of type 'OccupationType' are not supported. Only common simple .NET types are currently supported.
   at Microsoft.Data.Entity.Infrastructure.TypedAnnotation.CheckType(Type type)
   at Microsoft.Data.Entity.Infrastructure.TypedAnnotation..ctor(Object value)
   at Microsoft.Data.Entity.Metadata.RelationalPropertyAnnotations.SetDefaultValue(Object value)
   at Microsoft.Data.Entity.Metadata.RelationalPropertyAnnotations.set_DefaultValue(Object value)
   at Microsoft.Data.Entity.RelationalPropertyBuilderExtensions.HasDefaultValue(PropertyBuilder propertyBuilder, Object value)
   at Microsoft.Data.Entity.RelationalPropertyBuilderExtensions.HasDefaultValue[TProperty](PropertyBuilder`1 propertyBuilder, Object value)
   at SomeProject.Models.ApplicationDbContext.OnModelCreating(ModelBuilder builder) in C:\Users\Alexander\Work\Github\EvAlex\SomeProject\src\SomeProject.Website\Models\ApplicationDbContext.cs:line 24
   at Microsoft.Data.Entity.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.Data.Entity.Infrastructure.ModelSource.<>c__DisplayClass8_0.<GetModel>b__0(Type k)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Data.Entity.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator)
   at Microsoft.Data.Entity.Internal.DbContextServices.CreateModel()
   at Microsoft.Data.Entity.Internal.LazyRef`1.get_Value()
   at Microsoft.Data.Entity.Internal.DbContextServices.get_Model()
   at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c.<AddEntityFramework>b__0_5(IServiceProvider p)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.FactoryService.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.ScopedCallSite.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass12_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderExtensions.GetService[T](IServiceProvider provider)
   at Microsoft.Data.Entity.Design.Internal.DesignTimeServicesBuilder.<>c__DisplayClass7_0.<ConfigureContextServices>b__8(IServiceProvider _)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.FactoryService.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.TransientCallSite.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.TransientCallSite.Invoke(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass12_0.<RealizeService>b__0(ServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderExtensions.GetRequiredService[T](IServiceProvider provider)
   at Microsoft.Data.Entity.Design.MigrationsOperations.AddMigration(String name, String outputDir, String contextType)
   at Microsoft.Data.Entity.Commands.Program.Executor.<>c__DisplayClass6_0.<AddMigration>b__0()
   at Microsoft.Data.Entity.Commands.Program.Executor.Execute(Action action)

It turns out that the problem is default value type. The error is in default value configuration and the correct syntax is:

builder.Entity<Employee>()
    .Property(e => e.OccupationType)
    .HasDefaultValue((int)OccupationType.Fulltime);
//                   ^^^^^ here's the difference

The exception message is absolutely not clear.

[rowanmiller]

Related to #4061 (though that issue says we scaffold the migration, where as this issue fails generating the migration).

[bricelam]

@smitpatel Upon closer inspection, it looks the stack trace is purely in model building (getting DbContextServices.Model). Would you mind taking a look at this one?

[smitpatel]

The issue lies in TypedAnnotation. It supports a fixed set of types only. So having any other default value type would throw similar exception.
TypedAnnotation is being used by DefaultValue API only. It was added when Annotation did not support object type value. Is it still needed?
It was added by @ajcvickers in #861