Mongoose JS filter a virtual field by its length

filterVirtual.js

exports.getNewProblemsList = async (req, res, next) => {
  const page = req.params.page || 1;
  const limit = 10;
  const skip = page * limit - limit;

  const problemPromise = Problem.find()
    .populate('author hardware repairsV', 'name')
    .skip(skip)
    .limit(limit)
    .sort({ created: 1 })
    .select({
      photos: 0,
      description: 0,
      video: 0,
      board_model: 0,
    });

  const countPromise = Problem.count();

  const [problems, count] = await Promise.all([problemPromise, countPromise]);
  const pages = Math.ceil(count / limit);
  if (!problems.length && skip) {
    req.flash(
      'info',
      `You asked for page ${page} that does not exists. Redirecting to the page ${pages}!`
    );
    return;
  }
  
  // Here lies the problem, when you have a virtual field (here repairsV is virtual to Problem model from Virtual) you have many limitations.
  // Before passing it the the view as problemsZero, I filtered out only the problems that have zero repairs linked from the virtual field.
  
  problemsZero = problems.filter(problem => !problem.repairsV.length);

  res.locals.newProblemsList = {
    problems,
    problemsZero,
    page,
    pages,
    count,
  };
  next();
};