Method setUp

tests/test_patch.py:10–13

(self)

class TestPatch(unittest.TestCase):
    def setUp(self):
        self.test_file = Path("test_patch.txt")
        self.test_file.write_text("line 1\nline 2\nline 2\nline 3")
        _history.clear()

    def tearDown(self):
        if self.test_file.exists():