Index direction ignored in index_specifications

 ruby

require 'mongoid'

class Foo

  include Mongoid::Document

  field :x

  index(x: -1)

  index(x: 1)

end

Foo.index_specifications.each do |spec|

  p spec

end

This only yields a single index specification:

[#<Mongoid::Indexable::Specification:0x007fdb8f45c4b0 @klass=Foo, @key={:x=>-1}, @options={}>] 

This is definitely a change from 3.x, but I wonder whether it's by design? I am not clear whether having an index in both directions actually does anything in MongoDB, so if it's not a regression it should at least be documented.