Mercurial > hg
view tests/test-atomictempfile.py @ 34036:fe04c018eaac
filemerge: add _restorebackup
Differential Revision: https://phab.mercurial-scm.org/D404
author | Phil Cohen <phillco@fb.com> |
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date | Thu, 31 Aug 2017 11:28:59 -0700 |
parents | 68c43a416585 |
children | 3ec9afb951a0 |
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from __future__ import absolute_import import glob import os import shutil import tempfile import unittest from mercurial import ( util, ) atomictempfile = util.atomictempfile class testatomictempfile(unittest.TestCase): def setUp(self): self._testdir = tempfile.mkdtemp('atomictempfiletest') self._filename = os.path.join(self._testdir, 'testfilename') def tearDown(self): shutil.rmtree(self._testdir, True) def testsimple(self): file = atomictempfile(self._filename) self.assertFalse(os.path.isfile(self._filename)) tempfilename = file._tempname self.assertTrue(tempfilename in glob.glob( os.path.join(self._testdir, '.testfilename-*'))) file.write(b'argh\n') file.close() self.assertTrue(os.path.isfile(self._filename)) self.assertTrue(tempfilename not in glob.glob( os.path.join(self._testdir, '.testfilename-*'))) # discard() removes the temp file without making the write permanent def testdiscard(self): file = atomictempfile(self._filename) (dir, basename) = os.path.split(file._tempname) file.write(b'yo\n') file.discard() self.assertFalse(os.path.isfile(self._filename)) 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 testoops(self): with self.assertRaises(TypeError): atomictempfile() # checkambig=True avoids ambiguity of timestamp def testcheckambig(self): def atomicwrite(checkambig): f = atomictempfile(self._filename, checkambig=checkambig) f.write('FOO') f.close() # try some times, because reproduction of ambiguity depends on # "filesystem time" for i in xrange(5): atomicwrite(False) oldstat = os.stat(self._filename) if oldstat.st_ctime != oldstat.st_mtime: # subsequent changing never causes ambiguity continue repetition = 3 # repeat atomic write with checkambig=True, to examine # whether st_mtime is advanced multiple times as expected for j in xrange(repetition): atomicwrite(True) newstat = os.stat(self._filename) if oldstat.st_ctime != newstat.st_ctime: # timestamp ambiguity was naturally avoided while repetition continue # st_mtime should be advanced "repetition" times, because # all atomicwrite() occurred at same time (in sec) self.assertTrue(newstat.st_mtime == ((oldstat.st_mtime + repetition) & 0x7fffffff)) # no more examination is needed, if assumption above is true break else: # This platform seems too slow to examine anti-ambiguity # of file timestamp (or test happened to be executed at # bad timing). Exit silently in this case, because running # on other faster platforms can detect problems pass def testread(self): with open(self._filename, 'wb') as f: f.write(b'foobar\n') file = atomictempfile(self._filename, mode='rb') self.assertTrue(file.read(), b'foobar\n') file.discard() def testcontextmanagersuccess(self): """When the context closes, the file is closed""" with atomictempfile('foo') as f: self.assertFalse(os.path.isfile('foo')) f.write(b'argh\n') self.assertTrue(os.path.isfile('foo')) def testcontextmanagerfailure(self): """On exception, the file is discarded""" try: with atomictempfile('foo') as f: self.assertFalse(os.path.isfile('foo')) f.write(b'argh\n') raise ValueError except ValueError: pass self.assertFalse(os.path.isfile('foo')) if __name__ == '__main__': import silenttestrunner silenttestrunner.main(__name__)