view tests/test-symlink-os-yes-fs-no.py @ 35190:bd8875b6473c

run-tests: mechanism to report exceptions during test execution

Sometimes when running tests you introduce a ton of exceptions.
The most extreme example of this is running Mercurial with Python 3,
which currently spews thousands of exceptions when running the test
harness.

This commit adds an opt-in feature to run-tests.py to aggregate
exceptions encountered by `hg` when running tests.

When --exceptions is used, the test harness enables the
"logexceptions" extension in the test environment. This extension
wraps the Mercurial function to handle exceptions and writes
information about the exception to a random filename in a directory
defined by the test harness via an environment variable. At the
end of the test harness, these files are parsed, aggregated, and
a list of all unique Mercurial frames triggering exceptions is
printed in order of frequency.

This feature is intended to aid Python 3 development. I've only
really tested it on Python 3. There is no shortage of improvements
that could be made. e.g. we could write a separate file containing
the exception report - maybe even an HTML report. We also don't
capture which tests demonstrate the exceptions, so there's no turnkey
way to test whether a code change made an exception disappear.
Perfect is the enemy of good. I think the current patch is useful
enough to land. Whoever uses it can send patches to imprve its
usefulness.

Differential Revision: https://phab.mercurial-scm.org/D1477

from __future__ import absolute_import

import os
import sys
import time
from mercurial import (
    commands,
    hg,
    ui as uimod,
    util,
)

TESTDIR = os.environ["TESTDIR"]
BUNDLEPATH = os.path.join(TESTDIR, 'bundles', 'test-no-symlinks.hg')

# only makes sense to test on os which supports symlinks
if not getattr(os, "symlink", False):
    sys.exit(80) # SKIPPED_STATUS defined in run-tests.py

u = uimod.ui.load()
# hide outer repo
hg.peer(u, {}, '.', create=True)

# clone with symlink support
hg.clone(u, {}, BUNDLEPATH, 'test0')

repo = hg.repository(u, 'test0')

# wait a bit, or the status call wont update the dirstate
time.sleep(1)
commands.status(u, repo)

# now disable symlink support -- this is what os.symlink would do on a
# non-symlink file system
def symlink_failure(src, dst):
    raise OSError(1, "Operation not permitted")
os.symlink = symlink_failure
def islink_failure(path):
    return False
os.path.islink = islink_failure

# dereference links as if a Samba server has exported this to a
# Windows client
for f in 'test0/a.lnk', 'test0/d/b.lnk':
    os.unlink(f)
    fp = open(f, 'wb')
    fp.write(util.readfile(f[:-4]))
    fp.close()

# reload repository
u = uimod.ui.load()
repo = hg.repository(u, 'test0')
commands.status(u, repo)

# try cloning a repo which contains symlinks
u = uimod.ui.load()
hg.clone(u, {}, BUNDLEPATH, 'test1')