Query by nullable property fails with "Null TypeMapping in Sql Tree"

[myshon]

Following example worked correctly in EF Core 2.1, however it fails after update to 3.1

Steps to reproduce

Assume we have entities with nullable property Category

public enum TaxCategory
{
    Vat = 1,
    
    Fee = 2,

    Other = 3
}

public class Transaction
{
    public Guid Id { get; set; }
    
    public decimal Amount { get; set; }
    
    public TaxCategory? Category { get; set; }
}

The mappings is straightforward

public class TestContext : DbContext
{
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<Transaction>(b =>
        {
            b.HasKey(x => x.Id);
        });
    }
}

Following test fails

[Fact]
public async Task ShouldFilterByOptionalProperty()
{
    using (var context = new TestContext())
    {
        var t1 = new Transaction
        {
            Id = Guid.NewGuid(),
            Amount = 100M,
            Category = TaxCategory.Fee,
        };

        var t2 = new Transaction
        {
            Id = Guid.NewGuid(),
            Amount = 200M,
            Category = TaxCategory.Other,
        };
    
        var t3 = new Transaction
        {
            Id = Guid.NewGuid(),
            Amount = 50M,
        };
    
        await context.Set<Transaction>().AddRangeAsync(t1, t2, t3);
        await context.SaveChangesAsync();
    }

    using (var context = new TestContext())
    {
        var categories = new[] {TaxCategory.Fee, TaxCategory.Other};

        // it fails :(
        var items = await context.Set<Transaction>()
            .Where(x => x.Category != null && categories.Contains(x.Category.Value))
            .ToArrayAsync();
        
        Assert.Equal(2, items.Length);
    }
}

The test throws exception

System.InvalidOperationException : Null TypeMapping in Sql Tree
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.SqlTypeMappingVerifyingExpressionVisitor.VisitExtension(Expression node)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.Expressions.Internal.ArrayAnyAllExpression.VisitChildren(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.VisitExtension(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.SqlTypeMappingVerifyingExpressionVisitor.VisitExtension(Expression node)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Query.Expressions.Internal.ArrayAnyAllExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.SqlExpressions.SqlBinaryExpression.VisitChildren(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.VisitExtension(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.SqlTypeMappingVerifyingExpressionVisitor.VisitExtension(Expression node)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.SqlExpressions.SqlBinaryExpression.VisitChildren(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.VisitExtension(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.SqlTypeMappingVerifyingExpressionVisitor.VisitExtension(Expression node)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateExpression(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateLambdaExpression(ShapedQueryExpression shapedQueryExpression, LambdaExpression lambdaExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   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__DisplayClass12_0`1.<ExecuteAsync>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   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 Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToArrayAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)

Further technical details

EF Core version:
PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.3"
PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.1.3"
PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="3.1.3"

[smitpatel]

Same root cause and fixed in #20624