require_relative 'helper'

class TestMemoryLeaks < Test::Unit::TestCase
  include Examples

  def test_memory_prof
    5.times do
      1000.times do |i|
        brief_example
      end

      change = change_to_real_memory_in_kb
      assert change < 10_000, 'memory leak #{change}kb'
    end
  end

  def real_memory_in_kb
    # "=" after "rss" strips the header line.
    `ps -p #{Process.pid} -o rss=`.to_i
  end

  def change_to_real_memory_in_kb
    GC.start
    r = real_memory_in_kb
    @change_to_real_memory_in_kb__prev ||= r
    r - @change_to_real_memory_in_kb__prev
  ensure
    @change_to_real_memory_in_kb__prev = r
  end
end