ComplexProperty creates a migration loop after upgrading from 9.0.7 to 10.0.0-preview.6.25358.103

[jscarle]

Bug description

@roji I don't know how to be able to repro this without spending hours trying to tear down my existing project. So I'll try to provide as much context as possible, but essentially I have an .NET 10 minimal API based project that uses EntityFrameworkCore 9.0.7. If I upgrade to version 10.0.0-preview.6.25358.103 and create a new migration with absolutely no code changes, it create a migration for all of the columns where a ComplexProperty is configured. Even if I create the migration, it will throw PendingModelChangesWarning on startup. I can create as many migrations as I'd like, they're always identical.

My best guess is that it seems to be related to detecting nullability around structs.

Your code

Relevants bits of code:

public sealed class City
{
    public int CityId { get; init; }
    public required Coordinates Location { get; init; }
}

internal sealed class CityConfiguration : IEntityTypeConfiguration<City>
{
    public void Configure(EntityTypeBuilder<City> entity)
    {
        entity.HasKey(e => e.CityId);

        entity.Property(e => e.CityId)
            .ValueGeneratedOnAdd();
        entity.ComplexProperty(e => e.Location, builder =>
            {
                builder.Property(e => e.Latitude)
                    .HasColumnType("decimal(9, 6)");
                builder.Property(e => e.Longitude)
                    .HasColumnType("decimal(9, 6)");
            }
        );
    }
}

// Value objects have been simplified
public readonly struct Coordinates
{
    public Latitude Latitude { get; init; }
    public Longitude Longitude { get; init; }
}

public readonly struct Coordinates
{
    public Latitude Latitude { get; private init; }
    public Longitude Longitude { get; private init; }

    private Coordinates()
    {
    }

    public static Coordinates Create(Latitude latitude, Longitude longitude)
    {
        return new Coordinates { Latitude = latitude, Longitude = longitude };
    }
}

public readonly struct Latitude
{
    private decimal _value;

    private Latitude(decimal value)
    {
        _value = value;
    }

    public static Latitude Create(decimal value)
    {
        return new Latitude(value);
    }

    public decimal ToDecimal()
    {
        return _value;
    }
}

public readonly struct Longitude
{
    private decimal _value;

    private Longitude(decimal value)
    {
        _value = value;
    }

    public static Longitude Create(decimal value)
    {
        return new Longitude(value);
    }

    public decimal ToDecimal()
    {
        return _value;
    }
}

I wire up value converters around Latitude and Longitude.

The migrations it will create will look like this:

using Microsoft.EntityFrameworkCore.Migrations;

#nullable disable

namespace Database.Migrations
{
    /// <inheritdoc />
    public partial class PendingModelChanges : Migration
    {
        /// <inheritdoc />
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterColumn<decimal>(
                name: "Longitude",
                table: "City",
                type: "decimal(9,6)",
                nullable: false,
                defaultValue: 0m,
                oldClrType: typeof(decimal),
                oldType: "decimal(9,6)",
                oldNullable: true);

            migrationBuilder.AlterColumn<decimal>(
                name: "Latitude",
                table: "City",
                type: "decimal(9,6)",
                nullable: false,
                defaultValue: 0m,
                oldClrType: typeof(decimal),
                oldType: "decimal(9,6)",
                oldNullable: true);
        }

        /// <inheritdoc />
        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterColumn<decimal>(
                name: "Longitude",
                table: "City",
                type: "decimal(9,6)",
                nullable: true,
                oldClrType: typeof(decimal),
                oldType: "decimal(9,6)");

            migrationBuilder.AlterColumn<decimal>(
                name: "Latitude",
                table: "City",
                type: "decimal(9,6)",
                nullable: true,
                oldClrType: typeof(decimal),
                oldType: "decimal(9,6)");
        }
    }
}

I wish I could provide better code examples, but there's a lot of code dependencies that make it complex for me to water down my project into a focused repro.

EF Core version

10.0.0-preview.6.25358.103

Database provider

Microsoft.EntityFrameworkCore.SqlServer

Target framework

.NET 10.0.0-preview.6.25358.103

Operating system

Windows 11

IDE

JetBrains Rider 2025.2 RC 1

[MihuBot]

Possible related and/or duplicate issues:

• PendingModelChangesWarning exception thrown when upgrading to .NET 9 #35158
• PendingModelChangesWarning DotNet upgrade 9 #35404
• Unexpected PendingModelChangesWarning on initial creation of database via migrations #35110
• Background and information around the 9.0 PendingModelChangesWarning error #35285

[roji]

/cc @AndriySvyryd

[jscarle]

@roji @AndriySvyryd If you have a channel I can use, I can gladly send you my code base "as-is" to facilitate replicating the issue.

[roji]

@jscarle as always, ideally you'd simply post a minimal, runnable repro here. We generally don't have the resources to accept full projects as-is and work out how they function etc.

[jscarle]

@roji I'm just not sure how I could effectively create a minimal repro with this specific issue. I suppose I could create a new project that tries to replicate the minimum setup for that particular value object. I'll give it a try by duplicating my current codebase, deleting as much as I can from it and try to isolate the code that may recreate this bug.

[jscarle]

@roji @AndriySvyryd I spent a few hours stripping down and deleting code from my project and managed to bring it down to a minimal single file repro. Turns out the issue is not when going from 9.0.7, it's a bug that's present in 10.0.0-preview.6.25358.103 because doing an initial migration with 10.0.0-preview.6.25358.103 and then doing subsequent migrations using the same version has the same behavior.

Initial migration will create the following:

        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.CreateTable(
                name: "Company",
                columns: table => new
                {
                    Location_Latitude = table.Column<decimal>(type: "decimal(18,2)", nullable: false),
                    Location_Longitude = table.Column<decimal>(type: "decimal(18,2)", nullable: false)
                },
                constraints: table =>
                {
                });
        }

Subsequent migrations will create this forever:

        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterColumn<decimal>(
                name: "Location_Longitude",
                table: "Company",
                type: "decimal(18,2)",
                nullable: false,
                defaultValue: 0m,
                oldClrType: typeof(decimal),
                oldType: "decimal(18,2)",
                oldNullable: true);

            migrationBuilder.AlterColumn<decimal>(
                name: "Location_Latitude",
                table: "Company",
                type: "decimal(18,2)",
                nullable: false,
                defaultValue: 0m,
                oldClrType: typeof(decimal),
                oldType: "decimal(18,2)",
                oldNullable: true);
        }

Minimal repro csproj file:

<Project Sdk="Microsoft.NET.Sdk.Web">

    <PropertyGroup>
        <TargetFramework>net10.0</TargetFramework>
        <Nullable>enable</Nullable>
        <ImplicitUsings>enable</ImplicitUsings>
        <LangVersion>preview</LangVersion>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.0-preview.6.25358.103">
            <PrivateAssets>all</PrivateAssets>
            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
        </PackageReference>
        <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="10.0.0-preview.6.25358.103"/>
        <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.NetTopologySuite" Version="10.0.0-preview.6.25358.103"/>
    </ItemGroup>

</Project>

Minimal repro Program.cs:

using System.Globalization;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using Repro36494;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddDbContext<ApplicationDbContext>();

var app = builder.Build();

await app.RunAsync();

namespace Repro36494
{
    public sealed class ApplicationDbContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer();
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Company>()
                .HasNoKey()
                .ComplexProperty(e => e.Location, propertyBuilder =>
                    {
                        propertyBuilder.Property(e => e.Latitude);
                        propertyBuilder.Property(e => e.Longitude);
                    }
                );
        }

        protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
        {
            configurationBuilder.Properties<Latitude>()
                .HaveConversion<LatitudeConverter>();
            configurationBuilder.Properties<Longitude>()
                .HaveConversion<LongitudeConverter>();
        }
    }

    public sealed class Company
    {
        public Coordinates Location { get; init; }
    }

    internal sealed class LatitudeConverter() : ValueConverter<Latitude, decimal>(latitude => latitude.ToDecimal(), value => new Latitude(value));

    internal sealed class LongitudeConverter() : ValueConverter<Longitude, decimal>(longitude => longitude.ToDecimal(), value => new Longitude(value));

    public readonly struct Coordinates(Latitude latitude, Longitude longitude)
    {
        public Latitude Latitude { get; } = latitude;
        public Longitude Longitude { get; } = longitude;

        public override string ToString()
        {
            return $"{Latitude}, {Longitude}";
        }
    }

    public readonly struct Latitude(decimal value)
    {
        public decimal ToDecimal()
        {
            return value;
        }

        public override string ToString()
        {
            return value.ToString("F6", CultureInfo.InvariantCulture);
        }
    }

    public readonly struct Longitude(decimal value)
    {
        public decimal ToDecimal()
        {
            return value;
        }

        public override string ToString()
        {
            return value.ToString("F6", CultureInfo.InvariantCulture);
        }
    }
}

Public repository for repro (MIT licensed): https://github.com/jscarle/Repro36494

[AndriySvyryd]

@jscarle Thanks! That pinpointed the bug in the snapshot generator related to handling complex properties of value type.

[jscarle]

@AndriySvyryd Thank you for looking into it!