DateOnly.AddDays, Months and Years can't be projected out

[pil0t]

Here is the code to reproduce the bug:

using Microsoft.EntityFrameworkCore;
using Npgsql;
using Xunit;

namespace DateOnlyNpgsql;

public class TestEntity
{
    public int Id { get; set; }
    public DateOnly Date { get; set; }
    public int Diff { get; set; }
}

public class MyTest
{
    [Fact]
    public async Task InvalidCastExample()
    {
        var x = new DbCtx();
        await x.Database.EnsureDeletedAsync();
        await x.Database.EnsureCreatedAsync();
        var e = new TestEntity()
        {
            Id = 1,
            Date = DateOnly.Parse("2023-09-26"),
            Diff = 1
        };
        x.TestEntities.Add(e);
        await x.SaveChangesAsync();

        var query = x.TestEntities
            .Select(x => new
            {
                x.Id,
                NextMonth = x.Date.AddDays(x.Diff)
            });

        // System.InvalidCastException: Can't cast database type timestamp without time zone to DateOnly
        var a1 = query.ToArray();
    }

}

public class DbCtx : DbContext
{
    public DbSet<TestEntity> TestEntities { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseNpgsql(
            new NpgsqlConnection("Host=localhost;Uid=postgres;Pwd=mysecretpassword;Database=DummyDatabase"));
}

Tested on 6.0.22 and 7.0.11

[roji]

Thanks @pil0t, I can see this bug and will work on a fix.