Hey guys,

I think I've found a very weird bug. It appears that calling #map on a activerecord relation instance breaks #total_count, but only when the relation is empty. I've successfully reproduced it using both PostgreSQL and SQLite in their latest versions.

You can get a better vision of the issue in the code below:

def get_coupons(request, options)
  coupons = coupons(request)

  CouponsResponse.new(
    coupons: parsed_coupons(coupons), total: coupons.total_count,
    results_per_page: 10)
end

private

def coupons(request)
  Coupon.valid_at(request.valid_from).page(request.page).per(10)
end

def parsed_coupons(coupons)
  coupons.map do |coupon|
    ...
  end
end

The expected result is:

{ coupons: [...], total: 2, results_per_page: 10 }

While the actual result is:

{ coupons: [...], total: 10, results_per_page: 10 }

I tried searching the issues but didn't find anything related. Please forgive me if this is a known issue, or if it's my fault and therefore not an issue at all.