Method test_win_impl

Lib/test/test_shutil.py:3141–3168

(self)

    @unittest.skipIf(os.name != 'nt', "Windows only")
    def test_win_impl(self):
        # Make sure alternate Windows implementation is called.
        with unittest.mock.patch("shutil._copyfileobj_readinto") as m:
            shutil.copyfile(TESTFN, TESTFN2)
        assert m.called

        # File size is 2 MiB but max buf size should be 1 MiB.
        self.assertEqual(m.call_args[0][2], 1 * 1024 * 1024)

        # If file size < 1 MiB memoryview() length must be equal to
        # the actual file size.
        with tempfile.NamedTemporaryFile(dir=os.getcwd(), delete=False) as f:
            f.write(b'foo')
        fname = f.name
        self.addCleanup(os_helper.unlink, fname)
        with unittest.mock.patch("shutil._copyfileobj_readinto") as m:
            shutil.copyfile(fname, TESTFN2)
        self.assertEqual(m.call_args[0][2], 3)

        # Empty files should not rely on readinto() variant.
        with tempfile.NamedTemporaryFile(dir=os.getcwd(), delete=False) as f:
            pass
        fname = f.name
        self.addCleanup(os_helper.unlink, fname)
        with unittest.mock.patch("shutil._copyfileobj_readinto") as m:
            shutil.copyfile(fname, TESTFN2)
        assert not m.called
        self.assert_files_eq(fname, TESTFN2)


class _ZeroCopyFileTest(object):