ArgumentException thrown when building queries involving owned entities mapped with .ToJson()

[bperc2]

After updating my project from versions 7.0.15 to 8.0.1, I'm encountering an exception with queries against a model that used to work before the upgrade. The part of the model that appears to be the hang-up involves:

• An entity that owns many of something mapped with .ToJson()
• That owned entity owns many of another kind of entity
• These relationships involve properties and fields of differing types (property is an interface, field is concrete)

Here is a runnable example to demonstrate

using Microsoft.EntityFrameworkCore;

try
{
    using TestContext db = new();
    db.Database.EnsureCreated();

    var allOneLevelReviews = db.OneLevelReviews.ToList();

    // Exception occurs here
    var allReviews = db.Reviews.ToList();
    Console.WriteLine("OK");

}
catch (Exception ex)
{
    var exceptionString = ex.ToString();
    Console.WriteLine(ex.ToString());
}

Console.ReadLine();


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

    private List<ReviewRound> _rounds = [];
    public IReadOnlyList<ReviewRound> Rounds => _rounds.AsReadOnly();
}

public class ReviewRound
{
    public int RoundNumber { get; set; }

    private List<SubRound> _subRounds = [];
    public IReadOnlyList<SubRound> SubRounds => _subRounds.AsReadOnly();
}

public class SubRound
{
    public int SubRoundNumber { get; set; }

}

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

    private List<SubRound> _subRounds = [];
    public IReadOnlyList<SubRound> SubRounds => _subRounds.AsReadOnly();
}



public class TestContext : DbContext
{
    public DbSet<Review> Reviews { get; set; }
    public DbSet<OneLevelReview> OneLevelReviews { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        options
            .UseSqlServer(
                "...",
                providerOptions => providerOptions.EnableRetryOnFailure())
            .EnableDetailedErrors()
            .EnableSensitiveDataLogging();
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Review>().OwnsMany(x => x.Rounds, ownedBuilder =>
        {
            ownedBuilder.ToJson();

            ownedBuilder.OwnsMany(r => r.SubRounds);
        });

        modelBuilder.Entity<OneLevelReview>().OwnsMany(x => x.SubRounds, ownedBuilder =>
        {
            ownedBuilder.ToJson();
        });
    }
}

Include stack traces

System.ArgumentException
  HResult=0x80070057
  Message=Expression of type 'System.Collections.Generic.IReadOnlyList`1[SubRound]' cannot be used for assignment to type 'System.Collections.Generic.List`1[SubRound]'
  Source=System.Linq.Expressions
  StackTrace:
   at System.Linq.Expressions.Expression.Assign(Expression left, Expression right)
   at Microsoft.EntityFrameworkCore.Infrastructure.ExpressionExtensions.Assign(MemberExpression memberExpression, Expression valueExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.ShaperProcessingExpressionVisitor.CreateJsonShapers(IEntityType entityType, Boolean nullable, ParameterExpression jsonReaderDataParameter, ParameterExpression keyValuesParameter, Expression parentEntityExpression, INavigation navigation)
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.ShaperProcessingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.ShaperProcessingExpressionVisitor.ProcessShaper(Expression shaperExpression, RelationalCommandCache& relationalCommandCache, IReadOnlyList`1& readerColumns, LambdaExpression& relatedDataLoaders, Int32& collectionId)
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.VisitShapedQuery(ShapedQueryExpression shapedQueryExpression)
   at Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass9_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetEnumerator()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Collections.Generic.IEnumerable<TEntity>.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

Include provider and version information

EF Core version: 8.0.1
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: .NET 8

[maumar]

note: code works fine when _rounds, _subRounds and _subRounds are defined as readonly fields

private readonly List<ReviewRound> _rounds = [];

[bperc2]

I appreciate the quick response. Making my list fields readonly will work fine.

[maumar]

when building MaterializeJsonEntityCollection method call, we take navigation.ClrType as target collection type. In reality the logic is more complicated. We should do something like navigation.GetMemberInfo(...).GetMemberType() instead.