import contextlib
import io
import sys
import unittest


class CfgCheckerTestBase(unittest.TestCase):
    dummy_base_var = 0

    def _safe_import_module(self, _str):
        _import_msg = ""
        _module = None

        try:
            _module = __import__(_str)
        except ImportError as e:
            _import_msg = e.message

        return _import_msg, _module

    @contextlib.contextmanager
    def redirect_output(self):
        save_stdout = sys.stdout
        save_stderr = sys.stderr
        sys.stdout = io.BytesIO()
        sys.stderr = io.BytesIO()
        yield
        sys.stdout = save_stdout
        sys.stderr = save_stderr