def test_la(self):
        """test the 'la' alias for 'ls -a'"""
        output = self.run_command("la", exitcode=0)
        self.assertIn(".hidden", output)
        self.assertIn(".", output)
        self.assertIn("..", output)
        self.assertIn("file1.txt", output)
        self.assertIn("file2.txt", output)
test the 'la' alias for 'ls -a'
tests/ls/test_ls.py