view contrib/dirstatenonnormalcheck.py @ 35201: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

# dirstatenonnormalcheck.py - extension to check the consistency of the
# dirstate's non-normal map
#
# For most operations on dirstate, this extensions checks that the nonnormalset
# contains the right entries.
# It compares the nonnormal file to a nonnormalset built from the map of all
# the files in the dirstate to check that they contain the same files.

from __future__ import absolute_import

from mercurial import (
    dirstate,
    extensions,
)

def nonnormalentries(dmap):
    """Compute nonnormal entries from dirstate's dmap"""
    res = set()
    for f, e in dmap.iteritems():
        if e[0] != 'n' or e[3] == -1:
            res.add(f)
    return res

def checkconsistency(ui, orig, dmap, _nonnormalset, label):
    """Compute nonnormalset from dmap, check that it matches _nonnormalset"""
    nonnormalcomputedmap = nonnormalentries(dmap)
    if _nonnormalset != nonnormalcomputedmap:
        ui.develwarn("%s call to %s\n" % (label, orig), config='dirstate')
        ui.develwarn("inconsistency in nonnormalset\n", config='dirstate')
        ui.develwarn("[nonnormalset] %s\n" % _nonnormalset, config='dirstate')
        ui.develwarn("[map] %s\n" % nonnormalcomputedmap, config='dirstate')

def _checkdirstate(orig, self, arg):
    """Check nonnormal set consistency before and after the call to orig"""
    checkconsistency(self._ui, orig, self._map, self._map.nonnormalset,
                     "before")
    r = orig(self, arg)
    checkconsistency(self._ui, orig, self._map, self._map.nonnormalset, "after")
    return r

def extsetup(ui):
    """Wrap functions modifying dirstate to check nonnormalset consistency"""
    dirstatecl = dirstate.dirstate
    devel = ui.configbool('devel', 'all-warnings')
    paranoid = ui.configbool('experimental', 'nonnormalparanoidcheck')
    if devel:
        extensions.wrapfunction(dirstatecl, '_writedirstate', _checkdirstate)
        if paranoid:
            # We don't do all these checks when paranoid is disable as it would
            # make the extension run very slowly on large repos
            extensions.wrapfunction(dirstatecl, 'normallookup', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'otherparent', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'normal', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'write', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'add', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'remove', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'merge', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'drop', _checkdirstate)