Mercurial > hg
view tests/test-atomictempfile.py @ 42619:20d0e59be79b
tests: show the files fields of changelogs for many merges
I don't think there's coverage for many of the subtle cases, and I
found it hard to understand what the code is doing by reading it. The
test takes 40s to run on a laptop, or 9s with --chg.
I have yet to find a description of what the files field is supposed
to be for merges. I thought it could be one of:
1. the files added/modified/removed relative to p1 (wouldn't seem
useful, but `hg diff -c -r mergerev` has this behavior)
2. the files with filelog nodes not in either parent (i.e., what is
needed to create a bundle out of a commit)
3. the files added/removed/modified files by merge itself [1]
It's clearly not 1, because file contents merges are symmetric. It's
clearly not 2 because removed files and exec bit changes are
listed. It's also not 3 but I think it's intended to be 3 and the
differences are bugs.
Assuming 3, the test shows that, for merges, the list of files both
overapproximates and underapproximates. All the cases involve file
changes not in the filelog but in the manifest (existence of file
at revision, exec bit and file vs symlink).
I didn't look at all underapproximations, but they looked minor. The
two overapproximations are problematic though because they both cause
potentially long lists of files when merging cleanly.
[1] even what it means for the merge commit itself to change a file is
not completely trivial. A file in the merge being the same as in one
of the parent is too lax as it would consider that merges change
nothing when they revert all the changes done on one side. The
criteria used in the test and in the next commit for "merge didn't
touch a file" is:
- the parents and the merge all have the same file
- or, one parent didn't touch the file and the other parent contains
the same file as the merge
Differential Revision: https://phab.mercurial-scm.org/D6612
author | Valentin Gatien-Baron <valentin.gatienbaron@gmail.com> |
---|---|
date | Tue, 02 Jul 2019 12:55:51 -0400 |
parents | ffa3026d4196 |
children | 2372284d9457 |
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from __future__ import absolute_import import glob import os import shutil import stat import tempfile import unittest from mercurial import ( pycompat, util, ) atomictempfile = util.atomictempfile if pycompat.ispy3: xrange = range class testatomictempfile(unittest.TestCase): def setUp(self): self._testdir = tempfile.mkdtemp(b'atomictempfiletest') self._filename = os.path.join(self._testdir, b'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, b'.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, b'.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(b'.')) # 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(b'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[stat.ST_CTIME] != oldstat[stat.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[stat.ST_CTIME] != newstat[stat.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) oldtime = (oldstat[stat.ST_MTIME] + repetition) & 0x7fffffff self.assertTrue(newstat[stat.ST_MTIME] == oldtime) # 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=b'rb') self.assertTrue(file.read(), b'foobar\n') file.discard() def testcontextmanagersuccess(self): """When the context closes, the file is closed""" with atomictempfile(b'foo') as f: self.assertFalse(os.path.isfile(b'foo')) f.write(b'argh\n') self.assertTrue(os.path.isfile(b'foo')) def testcontextmanagerfailure(self): """On exception, the file is discarded""" try: with atomictempfile(b'foo') as f: self.assertFalse(os.path.isfile(b'foo')) f.write(b'argh\n') raise ValueError except ValueError: pass self.assertFalse(os.path.isfile(b'foo')) if __name__ == '__main__': import silenttestrunner silenttestrunner.main(__name__)