EF Core 9 generates incorrect compiled models for negative enum sentinel values

[Atulin]

EF Core version: 9.0
Database provider: Npgsql (efcore.pg)
Target framework: .NET 9
Operating system: Windows 10
IDE: Rider 2024.3

Configuration:

builder
	.Property(cm => cm.Role)
	.IsRequired()
	.HasDefaultValue(EClubMemberRoles.User)
	.HasSentinel((EClubMemberRoles)(-1));

Compiled model:

var role = runtimeEntityType.AddProperty(
    "Role",
    typeof(EClubMemberRoles),
    propertyInfo: typeof(ClubMember).GetProperty("Role", BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly),
    fieldInfo: typeof(ClubMember).GetField("<Role>k__BackingField", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly),
    valueGenerated: ValueGenerated.OnAdd,
    sentinel: (EClubMemberRoles)-1);
role.AddAnnotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.None);
role.AddAnnotation("Relational:DefaultValue", EClubMemberRoles.User);

As you can see, it omits the parentheses around the -1 which leads to the error.

[cincuranet]

The error is CS0075: To cast a negative value, you must enclose the value in parentheses..

[ajcvickers]

@Atulin I am not able to reproduce this. Following this change: #31923, the generated code should contain role.SetSentinelFromProviderValue(-1);. This is what I get with my attempt to reproduce this with my code below. Can you please update my code so that it reproduces the error you are seeing, or attach a new, small, runnable project or post a small, runnable code listing that reproduces what you are seeing so that we can investigate.

var role = runtimeEntityType.AddProperty(
    "Role",
    typeof(EClubMemberRoles),
    propertyInfo: typeof(Sensor).GetProperty("Role", BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly),
    fieldInfo: typeof(Sensor).GetField("<Role>k__BackingField", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly),
    valueGenerated: ValueGenerated.OnAdd);
role.SetSentinelFromProviderValue(-1);
role.AddAnnotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.None);
role.AddAnnotation("Relational:DefaultValue", EClubMemberRoles.User);

Repro code:

public class ContextOfDoom : DbContext
{
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .EnableSensitiveDataLogging()
            .LogTo(Console.WriteLine, LogLevel.Information)
            .UseNpgsql();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Sensor>(b =>
        {
            b.Property(cm => cm.Role)
                .IsRequired()
                .HasDefaultValue(EClubMemberRoles.User)
                .HasSentinel((EClubMemberRoles)(-1));
        });
    }
}

public class Sensor
{
    public int Id { get; set; }
    public EClubMemberRoles Role { get; set; }
}

public enum EClubMemberRoles
{
    User,
    Admin
}

[Atulin]

I don't see the enum registered with NpgSQL according to its documentation. Your code probably treats the value as a plain int because of that, while mine somehow differs because the enums are registered.

I will edit your code shortly, soon as I'm home.

[Atulin]

@ajcvickers Here's a reproduction: https://github.com/Atulin/EfEnumTest

ModelEntityType.cs#L51 has the un-parenthesised -1 there. It's also the one enum that has been registered with NpgSQL according to the docs in Program.cs#L16. The unregistered enum uses very different code, however: ModelEntityType.cs#L41) uses .SetSentinelFromProviderValue(-1) instead of the sentinel: argument of .AddProperty() method.

Could it be related to NpgSQL, not to EF itself, after all?

As a side note, when the context is placed in a global namespace, it seems ef migrations add generates invalid code, with an empty using ; (20241204210350_Initial.cs#L1)