Failing test for https://github.com/mongoid/mongoid/issues/3676.

3676_test.rb

require 'mongoid'
require 'mongoid/support/query_counter'
require 'minitest/autorun'

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

Mongoid.configure.connect_to("mongoid_test")

class Address
  include Mongoid::Document
  embedded_in :person
end

class Person
  include Mongoid::Document
  embeds_many :addresses
end

class BugTest < Minitest::Test
  def test_pluck
    person = Person.create!
    person.addresses.create!

    assert_equal [person.id], Person.all.pluck(:id)
    assert_equal [person.addresses.first.id], person.addresses.pluck(:id)
  end
end