EnumVectorDataWriter throws InvalidOperationException if given an enum with non-consecutive values. #330

using DuckDB.NET.Data;

enum Mood : byte
{
    Happy = 1,
    Sad = 2,
    // Skip 3
    Neutral = 4
}

internal static class Program
{
    private static void Main()
    {
        var enumNames = Enum.GetNames<Mood>();
        var enumLabelsSql = string.Join(", ", enumNames.Select(n => $"'{n}'"));
        var enumTypeSql = $"CREATE TYPE Mood AS ENUM ({enumLabelsSql});";

        using var connection = new DuckDBConnection("Data Source=:memory:");
        connection.Open();

        using var command = connection.CreateCommand();

        command.CommandText = enumTypeSql;
        command.ExecuteNonQuery();

        command.CommandText = "CREATE TABLE EnumTest (Value Mood);";
        command.ExecuteNonQuery();

        var valuesToInsert = new[]
        {
            Mood.Happy,
            Mood.Sad,
            Mood.Neutral
        };

        using (var appender = connection.CreateAppender("EnumTest"))
        {
            foreach (var enumValue in valuesToInsert)
            {
                var row = appender.CreateRow();
                row.AppendValue(enumValue);
                row.EndRow();
            }
        }
    }
}