Using FrozenSet.Contains and enums throws ArgumentNullException: Value cannot be null (Parameter 'constructor')

[SapiensAnatis]

Hey, I was upgrading to .NET 9 and as part of that went from Npgsql.EntityFrameworkCore.PostgreSQL 8.0.10 to 9.0.1, and Microsoft.EntityFrameworkCore 8.0.10 to 9.0.0. I found that some previously-working code that used FrozenSet.Contains in a Where call no longer worked, and now throws an ArgumentNullException which appears to be inside Npgsql. (The stack trace is the only reason I'm opening an issue here and not in dotnet/efcore, let me know if I'm wrong!)

Here's a minimal repro:

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

await using var context = new BlogContext();
await context.Database.EnsureDeletedAsync();
await context.Database.EnsureCreatedAsync();

FrozenSet<TagValue> tags = [TagValue.Gaming, TagValue.Recipe];
// List<TagValue> tags = [TagValue.Gaming, TagValue.Recipe]; // this works

var existingEntities = await context
    .Tags.Where(t => tags.Contains(t.Value))
    .ToListAsync();

public class BlogContext : DbContext
{
    public DbSet<Tag> Tags { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseNpgsql("Host=localhost;User ID=postgres;Password=Abcd5678;Database=test")
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();
}

public class Tag
{
    public int Id { get; set; }
    public TagValue Value { get; set; }
}

public enum TagValue
{
    Recipe,
    Politics,
    Gaming
}

On version 9.0.2-ci.20241120T194418 this throws the following exception for me:

Unhandled exception. System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.ArgumentNullException: Value cannot be null. (Parameter 'constructor')
   at System.ArgumentNullException.Throw(String paramName)
   at System.ArgumentNullException.ThrowIfNull(Object argument, String paramName)
   at System.Linq.Expressions.Expression.New(ConstructorInfo constructor, IEnumerable`1 arguments)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.ValueConversion.NpgsqlArrayConverter`3.ArrayConversionExpression[TInput,TOutput,TConcreteOutput](LambdaExpression elementConversionExpression)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.ValueConversion.NpgsqlArrayConverter`3..ctor(ValueConverter elementConverter)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
   --- End of inner exception stack trace ---
   at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
   at System.Reflection.MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture)
   at System.Activator.CreateInstance(Type type, Object[] args)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.Mapping.NpgsqlArrayTypeMapping`3.CreateParameters(String storeType, RelationalTypeMapping elementMapping)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.Mapping.NpgsqlArrayTypeMapping`3..ctor(String storeType, RelationalTypeMapping elementTypeMapping)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.Mapping.NpgsqlArrayTypeMapping`3..ctor(RelationalTypeMapping elementTypeMapping)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
   --- End of inner exception stack trace ---
   at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
   at System.Reflection.MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture)
   at System.Activator.CreateInstance(Type type, Object[] args)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlTypeMappingSource.FindCollectionMapping(RelationalTypeMappingInfo info, Type modelType, Type providerType, CoreTypeMapping elementMapping)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.<>c.<FindMappingWithConversion>b__8_0(ValueTuple`4 k, RelationalTypeMappingSource self)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd[TArg](TKey key, Func`3 valueFactory, TArg factoryArgument)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMappingWithConversion(RelationalTypeMappingInfo mappingInfo, Type providerClrType, ValueConverter customConverter)
   at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingSource.FindMapping(Type type, IModel model, CoreTypeMapping elementMapping)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.NpgsqlSqlExpressionFactory.ApplyTypeMappingsOnItemAndArray(SqlExpression itemExpression, SqlExpression arrayExpression)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.Internal.NpgsqlQueryableMethodTranslatingExpressionVisitor.TranslateContains(ShapedQueryExpression source, Expression item)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.TranslateSubquery(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.<VisitMethodCall>g__TranslateAsSubquery|33_0(Expression expression, <>c__DisplayClass33_0&)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.Internal.NpgsqlSqlTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.TranslateInternal(Expression expression, Boolean applyDefaultTypeMapping)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.Translate(Expression expression, Boolean applyDefaultTypeMapping)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateExpression(Expression expression, Boolean applyDefaultTypeMapping)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateLambdaExpression(ShapedQueryExpression shapedQueryExpression, LambdaExpression lambdaExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.Internal.NpgsqlQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutorExpression[TResult](Expression query)
   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__DisplayClass11_0`1.<ExecuteCore>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteCore[TResult](Expression query, Boolean async, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at Program.<Main>$(String[] args) in C:\Users\jay0\Projects\EFCoreIssue35102\EFCoreIssue35102\Program.cs:line 13
   at Program.<Main>$(String[] args) in C:\Users\jay0\Projects\EFCoreIssue35102\EFCoreIssue35102\Program.cs:line 13
   at Program.<Main>(String[] args)

(ignore the project name, this initially presented similar to a different issue I found and I based the minimal reproduction off of the one I found there)

Notably, if I change the FrozenSet<TagValue> to be a List<TagValue>, it works. I can also insert a call to AsEnumerable before the Contains, which also fixes the issue. It also appears to be specific to enums, if I make the tags a string then it works with FrozenSet<string>

[roji]

Closing as a duplicate of dotnet/efcore#35102 on the EF side.

[cincuranet]

@roji This seems to be different issue. Using FrozenSet in dotnet/efcore#35102 repro works just fine. Based on the stack, this looks more like an issue in provider, because it happens later (in NpgsqlArrayConverter) in the pipeline compared to dotnet/efcore#35102.

[roji]

OK, thanks for checking! Will look on my side.

[WhatzGames]

@roji I'm sorry, I should've probably notified you before I took the initiative to go on a hunt. I spent some time to fiddle around and at least when running the repro with my PR, it's no longer an issue.