public void WhenAttachingWithNullOrDefaultPrimaryKeys()
{
var productAdded = TestHelpers.CreateProduct("1");
_context.Attach(productAdded);
Assert.Equal(EntityState.Added, _context.Entry(productAdded).State);
_context.Entry(productAdded).State = EntityState.Detached;
//can attach either on the context or the DbSet
_context.Product.Attach(productAdded);
Assert.Equal(EntityState.Added, _context.Entry(productAdded).State);
_context.Entry(productAdded).State = EntityState.Detached;
_context.Product.Update(productAdded);
Assert.Equal(EntityState.Added, _context.Entry(productAdded).State);
_context.Entry(productAdded).State = EntityState.Detached;
Assert.Throws <InvalidOperationException>(() =>
_context.Product.Remove(productAdded));
}
