tests/test-atomictempfile.py

demandimport: blacklist distutils.msvc9compiler (issue4475)

This module depends on _winreg, which is windows-only. Recent versions
of setuptools load distutils.msvc9compiler and expect it to
ImportError immediately when on non-Windows platforms, so we need to
let them do that. This breaks in an especially mystifying way, because
setuptools uses vars() on the imported module. We then throw an
exception, which vars doesn't pick up on well. For example:

In [3]: class wat(object):
   ...:     @property
   ...:     def __dict__(self):
   ...:         assert False
   ...:

In [4]: vars(wat())
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-4-2781ada5ffe6> in <module>()
----> 1 vars(wat())

TypeError: vars() argument must have __dict__ attribute

Which is similar to the problem we run into.

import os
import glob
import unittest
import silenttestrunner

from mercurial.util import atomictempfile

class testatomictempfile(unittest.TestCase):
    def test1_simple(self):
        if os.path.exists('foo'):
            os.remove('foo')
        file = atomictempfile('foo')
        (dir, basename) = os.path.split(file._tempname)
        self.assertFalse(os.path.isfile('foo'))
        self.assertTrue(basename in glob.glob('.foo-*'))

        file.write('argh\n')
        file.close()

        self.assertTrue(os.path.isfile('foo'))
        self.assertTrue(basename not in glob.glob('.foo-*'))

    # discard() removes the temp file without making the write permanent
    def test2_discard(self):
        if os.path.exists('foo'):
            os.remove('foo')
        file = atomictempfile('foo')
        (dir, basename) = os.path.split(file._tempname)

        file.write('yo\n')
        file.discard()

        self.assertFalse(os.path.isfile('foo'))
        self.assertTrue(basename not in os.listdir('.'))

    # if a programmer screws up and passes bad args to atomictempfile, they
    # get a plain ordinary TypeError, not infinite recursion
    def test3_oops(self):
        self.assertRaises(TypeError, atomictempfile)

if __name__ == '__main__':
    silenttestrunner.main(__name__)