Method test_utcfromtimestamp_limits

Lib/test/datetimetester.py:2924–2964

(self)

    @unittest.skipIf(sys.platform == "win32", "Windows doesn't support min timestamp")
    def test_utcfromtimestamp_limits(self):
        with self.assertWarns(DeprecationWarning):
            try:
                self.theclass.utcfromtimestamp(-2**32 - 1)
            except (OSError, OverflowError):
                self.skipTest("Test not valid on this platform")

        min_dt = self.theclass.min.replace(tzinfo=timezone.utc)
        min_ts = min_dt.timestamp()

        max_dt = self.theclass.max.replace(microsecond=0, tzinfo=timezone.utc)
        max_ts = max_dt.timestamp()

        for (test_name, ts, expected) in [
                ("minimum", min_ts, min_dt.replace(tzinfo=None)),
                ("maximum", max_ts, max_dt.replace(tzinfo=None)),
        ]:
            with self.subTest(test_name, ts=ts, expected=expected):
                with self.assertWarns(DeprecationWarning):
                    try:
                        actual = self.theclass.utcfromtimestamp(ts)
                    except (OSError, OverflowError) as exc:
                        self.skipTest(str(exc))

                self.assertEqual(actual, expected)

        # Test error conditions
        test_cases = [
            ("Too small by a little", min_ts - 1),
            ("Too small by a lot", min_ts - timedelta(days=400).total_seconds()),
            ("Too big by a little", max_ts + 1),
            ("Too big by a lot", max_ts + timedelta(days=400).total_seconds()),
        ]

        for test_name, ts in test_cases:
            with self.subTest(test_name, ts=ts):
                with self.assertRaises((ValueError, OverflowError)):
                    with self.assertWarns(DeprecationWarning):
                        # converting a Python int to C time_t can raise a
                        # OverflowError, especially on 32-bit platforms.
                        self.theclass.utcfromtimestamp(ts)

    def test_insane_fromtimestamp(self):
        # It's possible that some platform maps time_t to double,