Method drive_one

Lib/test/test_bufio.py:42–54

(self, pattern)

            os_helper.unlink(os_helper.TESTFN)

    def drive_one(self, pattern):
        for length in lengths:
            # Repeat string 'pattern' as often as needed to reach total length
            # 'length'.  Then call try_one with that string, a string one larger
            # than that, and a string one smaller than that.  Try this with all
            # small sizes and various powers of 2, so we exercise all likely
            # stdio buffer sizes, and "off by one" errors on both sides.
            q, r = divmod(length, len(pattern))
            teststring = pattern * q + pattern[:r]
            self.assertEqual(len(teststring), length)
            self.try_one(teststring)
            self.try_one(teststring + b"x")
            self.try_one(teststring[:-1])

    def test_primepat(self):
        # A pattern with prime length, to avoid simple relationships with