tahoe-lafs/src/allmydata/test/common_util.py
Jean-Paul Calderone 8593bf1b1c Make helper method compatible with other unittests
The msg keyword argument is overly precise.  testtools reasonably calls it
`message` instead.
2019-03-07 18:38:52 -05:00

278 lines
10 KiB
Python

import os, signal, sys, time
from random import randrange
from six.moves import StringIO
from twisted.internet import reactor, defer
from twisted.python import failure
from twisted.trial import unittest
from allmydata.util import fileutil, log
from ..util.assertutil import precondition
from allmydata.util.encodingutil import (unicode_platform, get_filesystem_encoding,
get_io_encoding)
from ..scripts import runner
def skip_if_cannot_represent_filename(u):
precondition(isinstance(u, unicode))
enc = get_filesystem_encoding()
if not unicode_platform():
try:
u.encode(enc)
except UnicodeEncodeError:
raise unittest.SkipTest("A non-ASCII filename could not be encoded on this platform.")
def skip_if_cannot_represent_argv(u):
precondition(isinstance(u, unicode))
try:
u.encode(get_io_encoding())
except UnicodeEncodeError:
raise unittest.SkipTest("A non-ASCII argv could not be encoded on this platform.")
def run_cli(verb, *args, **kwargs):
precondition(not [True for arg in args if not isinstance(arg, str)],
"arguments to do_cli must be strs -- convert using unicode_to_argv", args=args)
nodeargs = kwargs.get("nodeargs", [])
argv = nodeargs + [verb] + list(args)
stdin = kwargs.get("stdin", "")
stdout = StringIO()
stderr = StringIO()
d = defer.succeed(argv)
d.addCallback(runner.parse_or_exit_with_explanation, stdout=stdout)
d.addCallback(runner.dispatch,
stdin=StringIO(stdin),
stdout=stdout, stderr=stderr)
def _done(rc):
return 0, stdout.getvalue(), stderr.getvalue()
def _err(f):
f.trap(SystemExit)
return f.value.code, stdout.getvalue(), stderr.getvalue()
d.addCallbacks(_done, _err)
return d
def parse_cli(*argv):
# This parses the CLI options (synchronously), and returns the Options
# argument, or throws usage.UsageError if something went wrong.
return runner.parse_options(argv)
class DevNullDictionary(dict):
def __setitem__(self, key, value):
return
def insecurerandstr(n):
return ''.join(map(chr, map(randrange, [0]*n, [256]*n)))
def flip_bit(good, which):
# flip the low-order bit of good[which]
if which == -1:
pieces = good[:which], good[-1:], ""
else:
pieces = good[:which], good[which:which+1], good[which+1:]
return pieces[0] + chr(ord(pieces[1]) ^ 0x01) + pieces[2]
def flip_one_bit(s, offset=0, size=None):
""" flip one random bit of the string s, in a byte greater than or equal to offset and less
than offset+size. """
if size is None:
size=len(s)-offset
i = randrange(offset, offset+size)
result = s[:i] + chr(ord(s[i])^(0x01<<randrange(0, 8))) + s[i+1:]
assert result != s, "Internal error -- flip_one_bit() produced the same string as its input: %s == %s" % (result, s)
return result
class ReallyEqualMixin:
def failUnlessReallyEqual(self, a, b, msg=None):
self.assertEqual(a, b, msg)
self.assertEqual(type(a), type(b), "a :: %r, b :: %r, %r" % (a, b, msg))
class NonASCIIPathMixin:
def mkdir_nonascii(self, dirpath):
# Kludge to work around the fact that buildbot can't remove a directory tree that has
# any non-ASCII directory names on Windows. (#1472)
if sys.platform == "win32":
def _cleanup():
try:
fileutil.rm_dir(dirpath)
finally:
if os.path.exists(dirpath):
msg = ("We were unable to delete a non-ASCII directory %r created by the test. "
"This is liable to cause failures on future builds." % (dirpath,))
print msg
log.err(msg)
self.addCleanup(_cleanup)
os.mkdir(dirpath)
def unicode_or_fallback(self, unicode_name, fallback_name, io_as_well=False):
if not unicode_platform():
try:
unicode_name.encode(get_filesystem_encoding())
except UnicodeEncodeError:
return fallback_name
if io_as_well:
try:
unicode_name.encode(get_io_encoding())
except UnicodeEncodeError:
return fallback_name
return unicode_name
class SignalMixin(object):
# This class is necessary for any code which wants to use Processes
# outside the usual reactor.run() environment. It is copied from
# Twisted's twisted.test.test_process . Note that Twisted-8.2.0 uses
# something rather different.
sigchldHandler = None
def setUp(self):
# make sure SIGCHLD handler is installed, as it should be on
# reactor.run(). problem is reactor may not have been run when this
# test runs.
if hasattr(reactor, "_handleSigchld") and hasattr(signal, "SIGCHLD"):
self.sigchldHandler = signal.signal(signal.SIGCHLD,
reactor._handleSigchld)
return super(SignalMixin, self).setUp()
def tearDown(self):
if self.sigchldHandler:
signal.signal(signal.SIGCHLD, self.sigchldHandler)
return super(SignalMixin, self).tearDown()
class StallMixin:
def stall(self, res=None, delay=1):
d = defer.Deferred()
reactor.callLater(delay, d.callback, res)
return d
class ShouldFailMixin:
def shouldFail(self, expected_failure, which, substring,
callable, *args, **kwargs):
assert substring is None or isinstance(substring, str)
d = defer.maybeDeferred(callable, *args, **kwargs)
def done(res):
if isinstance(res, failure.Failure):
res.trap(expected_failure)
if substring:
self.failUnless(substring in str(res),
"%s: substring '%s' not in '%s'"
% (which, substring, str(res)))
# return the Failure for further analysis, but in a form that
# doesn't make the Deferred chain think that we failed.
return [res]
else:
self.fail("%s was supposed to raise %s, not get '%s'" %
(which, expected_failure, res))
d.addBoth(done)
return d
class TestMixin(SignalMixin):
def setUp(self, repeatable=False):
"""
@param repeatable: install the repeatable_randomness hacks to attempt
to without access to real randomness and real time.time from the
code under test
"""
self.repeatable = repeatable
if self.repeatable:
import repeatable_random
repeatable_random.force_repeatability()
if hasattr(time, 'realtime'):
self.teststarttime = time.realtime()
else:
self.teststarttime = time.time()
return super(TestMixin, self).setUp()
def tearDown(self):
if self.repeatable:
import repeatable_random
repeatable_random.restore_non_repeatability()
self.clean_pending(required_to_quiesce=True)
return super(TestMixin, self).tearDown()
def clean_pending(self, dummy=None, required_to_quiesce=True):
"""
This handy method cleans all pending tasks from the reactor.
When writing a unit test, consider the following question:
Is the code that you are testing required to release control once it
has done its job, so that it is impossible for it to later come around
(with a delayed reactor task) and do anything further?
If so, then trial will usefully test that for you -- if the code under
test leaves any pending tasks on the reactor then trial will fail it.
On the other hand, some code is *not* required to release control -- some
code is allowed to continuously maintain control by rescheduling reactor
tasks in order to do ongoing work. Trial will incorrectly require that
code to clean up all its tasks from the reactor.
Most people think that such code should be amended to have an optional
"shutdown" operation that releases all control, but on the contrary it is
good design for some code to *not* have a shutdown operation, but instead
to have a "crash-only" design in which it recovers from crash on startup.
If the code under test is of the "long-running" kind, which is *not*
required to shutdown cleanly in order to pass tests, then you can simply
call testutil.clean_pending() at the end of the unit test, and trial will
be satisfied.
"""
pending = reactor.getDelayedCalls()
active = bool(pending)
for p in pending:
if p.active():
p.cancel()
else:
print "WEIRDNESS! pending timed call not active!"
if required_to_quiesce and active:
self.fail("Reactor was still active when it was required to be quiescent.")
class TimezoneMixin(object):
def setTimezone(self, timezone):
def tzset_if_possible():
# Windows doesn't have time.tzset().
if hasattr(time, 'tzset'):
time.tzset()
unset = object()
originalTimezone = os.environ.get('TZ', unset)
def restoreTimezone():
if originalTimezone is unset:
del os.environ['TZ']
else:
os.environ['TZ'] = originalTimezone
tzset_if_possible()
os.environ['TZ'] = timezone
self.addCleanup(restoreTimezone)
tzset_if_possible()
def have_working_tzset(self):
return hasattr(time, 'tzset')
try:
import win32file
import win32con
def make_readonly(path):
win32file.SetFileAttributes(path, win32con.FILE_ATTRIBUTE_READONLY)
def make_accessible(path):
win32file.SetFileAttributes(path, win32con.FILE_ATTRIBUTE_NORMAL)
except ImportError:
import stat
def _make_readonly(path):
os.chmod(path, stat.S_IREAD)
os.chmod(os.path.dirname(path), stat.S_IREAD)
def _make_accessible(path):
os.chmod(os.path.dirname(path), stat.S_IWRITE | stat.S_IEXEC | stat.S_IREAD)
os.chmod(path, stat.S_IWRITE | stat.S_IEXEC | stat.S_IREAD)
make_readonly = _make_readonly
make_accessible = _make_accessible