new_contents: import os
  import unittest
  
  import stack
  
  
  class TestSlashConvert(unittest.TestCase):
      def test_relative(self):
          # start with unix-style
          source = "test/sub \n dir/file.txt"
  
          # convert to OS-specific separators; this is a no-op on unix-like systems
          os_slash = os.path.normpath(source)
  
          # check that the convert to unix-style gets us back to the start
          unix_slash = stack._to_unix_slashes(os_slash)
          self.assertEquals(unix_slash, source)
  
  
  if __name__ == '__main__':
      unittest.main()
subject: Add unit test for path conversion.