ConfigureSmartEnum not working

this is my ConfigureConventions

The smart enum

How I use it under entity

The exception 'No suitable constructor was found for entity type 'UnitMaterial'. The following constructors had parameters that could not be bound to properties of the entity type: Cannot bind 'name', 'value' in 'UnitMaterial(string name, int value)'

how can I fix this ? please help
UnitMaterial and Entity is under my DOMAIN project, and dbContext is under INFRASTRUCTURE project

My specs
.NET 8.0
SmartEnum 8.1
SmartEnum.EFCore 8.1

[HAOYI99]

can someone please help on this

[ardalis]

It looks right as is - if you create a minimal repo I can take a look.

As a workaround you can try this:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<YourEntity>()
        .Property(e => e.Unit)
        .HasConversion(
            v => v.Value, // Convert `SmartEnum` to its `value` (int)
            v => UnitMaterial.FromValue(v) // Convert `value` (int) back to `SmartEnum`
        );
}

[HAOYI99]

It looks right as is - if you create a minimal repo I can take a look.

As a workaround you can try this:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<YourEntity>()
        .Property(e => e.Unit)
        .HasConversion(
            v => v.Value, // Convert `SmartEnum` to its `value` (int)
            v => UnitMaterial.FromValue(v) // Convert `value` (int) back to `SmartEnum`
        );
}

Hi @ardalis, thanks for the reply.

yes, I did use this method to manual map the conversion for each SmartEnum.

However, the document mentioned ConfigureSmartEnum is sufficient for configuring all SmartEnum.

I tried many times, ends up I create a SmartEnumConverter myself.

public class SmartEnumConverter<TEnum>() : ValueConverter<TEnum, string>(
    enumValue => enumValue.Name,
    stringValue => SmartEnum<TEnum, int>.FromName(stringValue, true)
) where TEnum : SmartEnum<TEnum, int>;

and the builder.ConfigureSmartEnum(); is not required with this approach

public static void ConfigureSmartEnum<TEnum>(this ModelConfigurationBuilder builder) where TEnum : SmartEnum<TEnum, int>
{
     builder.Properties<TEnum>().HaveConversion<SmartEnumConverter<TEnum>>();
}

protected override void ConfigureConventions(ModelConfigurationBuilder builder)
{
    base.ConfigureConventions(builder);
    builder.Properties<DateOnly>().HaveConversion<DateOnlyConverter>().HaveColumnType("date");
    builder.Properties<DateTime>().HaveColumnType("datetime");
    builder.Properties<TimeSpan>().HaveConversion<long>();
    builder.Properties<Enum>().HaveConversion<string>();
    builder.ConfigureSmartEnum<UnitMaterial>();
    builder.ConfigureSmartEnum<AmTechnologies>();
}

[bengavin]

We are running into this same error when generating migrations since moving to .NET 9. Any entity that has changed since the previous migration and contains a smart enum generates this exception during the migration generation process, unless the workaround given by @ardalis is used in the entity configuration.

I should note that this doesn't seem to effect runtime operation at all, it only seems to be required during the migration generation process if that helps troubleshooting at all.

[ardalis]

Yeah EF Core must have changed something in v9 I guess. We'll take a look and figure out how to do a more general solution (again) as soon as we can. Community assistance appreciated as always, including reproductions of the problem in clean repos so if we come up with a fix we can test it with your scenario.

[jczacharia]

I encountered a similar issue:

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.ConfigureSmartEnum(); // Won't work here
        modelBuilder.ApplyConfigurationsFromAssembly(typeof(DbCtx).Assembly);
    }

I had to add it after ApplyConfigurationsFromAssembly, which seemed to do the trick.

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.ApplyConfigurationsFromAssembly(typeof(DbCtx).Assembly).ConfigureSmartEnum(); // Works here
    }

[gracewhitney]

Experimentally, it seems that calling HaveConversion after configurationBuilder.CreateModelBuilder now has no effect. I worked around this issue by getting the list of all enum property types in the assembly from Assembly.GetExecutingAssembly().GetTypes() (and then the same derived type filters) rather than using modelBuilder.Model.GetEntityTypes(), to avoid the CreateModelBuilder call. Not sure if that's a good general solution, but it at least avoids needing to register each enum individually.