Method test_open

Lib/test/test_codecs.py:1863–1868

(self)

            getattr(codecs, api)

    def test_open(self):
        self.addCleanup(os_helper.unlink, os_helper.TESTFN)
        for mode in ('w', 'r', 'r+', 'w+', 'a', 'a+'):
            with self.subTest(mode), self.assertWarns(DeprecationWarning):
                with codecs.open(os_helper.TESTFN, mode, 'ascii') as file:
                    self.assertIsInstance(file, codecs.StreamReaderWriter)

    def test_undefined(self):
        self.assertRaises(UnicodeError, codecs.encode, 'abc', 'undefined')