##// END OF EJS Templates
posix: always seek to EOF when opening a file in append mode...
posix: always seek to EOF when opening a file in append mode Python 3 already does this, so skip it there. Consider the program: #include <stdio.h> int main() { FILE *f = fopen("narf", "w"); fprintf(f, "narf\n"); fclose(f); f = fopen("narf", "a"); printf("%ld\n", ftell(f)); fprintf(f, "troz\n"); printf("%ld\n", ftell(f)); return 0; } on macOS, FreeBSD, and Linux with glibc, this program prints 5 10 but on musl libc (Alpine Linux and probably others) this prints 0 10 By my reading of https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html this is technically correct, specifically: > Opening a file with append mode (a as the first character in the > mode argument) shall cause all subsequent writes to the file to be > forced to the then current end-of-file, regardless of intervening > calls to fseek(). in other words, the file position doesn't really matter in append-mode files, and we can't depend on it being at all meaningful unless we perform a seek() before tell() after open(..., 'a'). Experimentally after a .write() we can do a .tell() and it'll always be reasonable, but I'm unclear from reading the specification if that's a smart thing to rely on. This matches what we do on Windows and what Python 3 does for free, so let's just be consistent. Thanks to Yuya for the idea.

File last commit:

r41925:aaad36b8 default
r43163:97ada9b8 5.0.2 stable
Show More
test-simplekeyvaluefile.py
90 lines | 3.0 KiB | text/x-python | PythonLexer
/ tests / test-simplekeyvaluefile.py
from __future__ import absolute_import
import unittest
import silenttestrunner
from mercurial import (
error,
scmutil,
)
class mockfile(object):
def __init__(self, name, fs):
self.name = name
self.fs = fs
def __enter__(self):
return self
def __exit__(self, *args, **kwargs):
pass
def write(self, text):
self.fs.contents[self.name] = text
def read(self):
return self.fs.contents[self.name]
class mockvfs(object):
def __init__(self):
self.contents = {}
def read(self, path):
return mockfile(path, self).read()
def readlines(self, path):
# lines need to contain the trailing '\n' to mock the real readlines
return [l for l in mockfile(path, self).read().splitlines(True)]
def __call__(self, path, mode, atomictemp):
return mockfile(path, self)
class testsimplekeyvaluefile(unittest.TestCase):
def setUp(self):
self.vfs = mockvfs()
def testbasicwritingiandreading(self):
dw = {b'key1': b'value1', b'Key2': b'value2'}
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(dw)
self.assertEqual(sorted(self.vfs.read(b'kvfile').split(b'\n')),
[b'', b'Key2=value2', b'key1=value1'])
dr = scmutil.simplekeyvaluefile(self.vfs, b'kvfile').read()
self.assertEqual(dr, dw)
if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
# Python 3.7 deprecates the regex*p* version, but 2.7 lacks
# the regex version.
assertRaisesRegex = (# camelcase-required
unittest.TestCase.assertRaisesRegexp)
def testinvalidkeys(self):
d = {b'0key1': b'value1', b'Key2': b'value2'}
with self.assertRaisesRegex(error.ProgrammingError,
'keys must start with a letter.*'):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
d = {b'key1@': b'value1', b'Key2': b'value2'}
with self.assertRaisesRegex(error.ProgrammingError, 'invalid key.*'):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
def testinvalidvalues(self):
d = {b'key1': b'value1', b'Key2': b'value2\n'}
with self.assertRaisesRegex(error.ProgrammingError, 'invalid val.*'):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
def testcorruptedfile(self):
self.vfs.contents[b'badfile'] = b'ababagalamaga\n'
with self.assertRaisesRegex(error.CorruptedState,
'dictionary.*element.*'):
scmutil.simplekeyvaluefile(self.vfs, b'badfile').read()
def testfirstline(self):
dw = {b'key1': b'value1'}
scmutil.simplekeyvaluefile(self.vfs, b'fl').write(dw, firstline=b'1.0')
self.assertEqual(self.vfs.read(b'fl'), b'1.0\nkey1=value1\n')
dr = scmutil.simplekeyvaluefile(
self.vfs, b'fl').read(firstlinenonkeyval=True)
self.assertEqual(dr, {b'__firstline': b'1.0', b'key1': b'value1'})
if __name__ == "__main__":
silenttestrunner.main(__name__)