view hgext/narrow/narrowcommands.py @ 39772:ae531f5e583c

testing: add interface unit tests for file storage

Our strategy for supporting alternate storage backends is to define
interfaces for everything then "code to the interface."

We already have interfaces for various primitives, including file
and manifest storage.

What we don't have is generic unit tests for those interfaces. Up
to this point we've been relying on high-level integration tests
(mainly in the form of existing .t tests) to test alternate storage
backends. And my experience with developing the "simple store" test
extension is that such testing is very tedious: it takes several
minutes to run all tests and when you find a failure, it is often
non-trivial to debug.

This commit starts to change that.

This commit introduces the mercurial.testing.storage module. It
contains testing code for storage. Currently, it defines some
unittest.TestCase classes for testing the file storage interfaces.
It also defines some factory functions that allow a caller to easily
spawn a custom TestCase "bound" to a specific file storage backend
implementation.

A new .py test has been added. It simply defines a callable to produce
filelog and transaction instances on demand and then "registers" the
various test classes so the filelog class can be tested with the
storage interface unit tests.

As part of writing the tests, I identified a couple of apparent
bugs in revlog.py and filelog.py! These are tracked with inline
TODO comments.

Writing the tests makes it more obvious where the storage interface
is lacking. For example, we raise either IndexError or
error.LookupError for missing revisions depending on whether we
use an integer revision or a node. Also, we raise error.RevlogError
in various places when we should be raising a storage-agnostic
error type.

The storage interfaces are currently far from perfect and there is much
work to be done to improve them. But at least with this commit we
finally have the start of unit tests that can be used to "qualify"
the behavior of a storage backend. And when implementing and debugging
new storage backends, we now have an obvious place to define new
tests and have obvious places to insert breakpoints to facilitate
debugging. This should be invaluable when implementing new storage
backends.

I added the mercurial.testing package because these interface
conformance tests are generic and need to be usable by all storage
backends. Having the code live in tests/ would make it difficult for
storage backends implemented in extensions to test their interface
conformance. First, it would require obtaining a copy of Mercurial's
storage test code in order to test. Second, it would make testing
against multiple Mercurial versions difficult, as you would need to
import N copies of the storage testing code in order to achieve test
coverage. By making the test code part of the Mercurial distribution
itself, extensions can `import mercurial.testing.*` to access and run
the test code. The test will run against whatever Mercurial version
is active.

FWIW I've always wanted to move parts of run-tests.py into the
mercurial.* package to make the testing story simpler (e.g. imagine an
`hg debugruntests` command that could invoke the test harness). While I
have no plans to do that in the near future, establishing the
mercurial.testing package does provide a natural home for that code
should someone do this in the future.

Differential Revision: https://phab.mercurial-scm.org/D4650

# narrowcommands.py - command modifications for narrowhg extension
#
# Copyright 2017 Google, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import

import itertools
import os

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    commands,
    discovery,
    encoding,
    error,
    exchange,
    extensions,
    hg,
    merge,
    narrowspec,
    node,
    pycompat,
    registrar,
    repair,
    repository,
    repoview,
    sparse,
    util,
)

from . import (
    narrowwirepeer,
)

table = {}
command = registrar.command(table)

def setup():
    """Wraps user-facing mercurial commands with narrow-aware versions."""

    entry = extensions.wrapcommand(commands.table, 'clone', clonenarrowcmd)
    entry[1].append(('', 'narrow', None,
                     _("create a narrow clone of select files")))
    entry[1].append(('', 'depth', '',
                     _("limit the history fetched by distance from heads")))
    entry[1].append(('', 'narrowspec', '',
                     _("read narrowspecs from file")))
    # TODO(durin42): unify sparse/narrow --include/--exclude logic a bit
    if 'sparse' not in extensions.enabled():
        entry[1].append(('', 'include', [],
                         _("specifically fetch this file/directory")))
        entry[1].append(
            ('', 'exclude', [],
             _("do not fetch this file/directory, even if included")))

    entry = extensions.wrapcommand(commands.table, 'pull', pullnarrowcmd)
    entry[1].append(('', 'depth', '',
                     _("limit the history fetched by distance from heads")))

    extensions.wrapcommand(commands.table, 'archive', archivenarrowcmd)

def clonenarrowcmd(orig, ui, repo, *args, **opts):
    """Wraps clone command, so 'hg clone' first wraps localrepo.clone()."""
    opts = pycompat.byteskwargs(opts)
    wrappedextraprepare = util.nullcontextmanager()
    narrowspecfile = opts['narrowspec']

    if narrowspecfile:
        filepath = os.path.join(pycompat.getcwd(), narrowspecfile)
        ui.status(_("reading narrowspec from '%s'\n") % filepath)
        try:
            fdata = util.readfile(filepath)
        except IOError as inst:
            raise error.Abort(_("cannot read narrowspecs from '%s': %s") %
                              (filepath, encoding.strtolocal(inst.strerror)))

        includes, excludes, profiles = sparse.parseconfig(ui, fdata, 'narrow')
        if profiles:
            raise error.Abort(_("cannot specify other files using '%include' in"
                                " narrowspec"))

        narrowspec.validatepatterns(includes)
        narrowspec.validatepatterns(excludes)

        # narrowspec is passed so we should assume that user wants narrow clone
        opts['narrow'] = True
        opts['include'].extend(includes)
        opts['exclude'].extend(excludes)

    if opts['narrow']:
        def pullbundle2extraprepare_widen(orig, pullop, kwargs):
            orig(pullop, kwargs)

            if opts.get('depth'):
                kwargs['depth'] = opts['depth']
        wrappedextraprepare = extensions.wrappedfunction(exchange,
            '_pullbundle2extraprepare', pullbundle2extraprepare_widen)

    with wrappedextraprepare:
        return orig(ui, repo, *args, **pycompat.strkwargs(opts))

def pullnarrowcmd(orig, ui, repo, *args, **opts):
    """Wraps pull command to allow modifying narrow spec."""
    wrappedextraprepare = util.nullcontextmanager()
    if repository.NARROW_REQUIREMENT in repo.requirements:

        def pullbundle2extraprepare_widen(orig, pullop, kwargs):
            orig(pullop, kwargs)
            if opts.get(r'depth'):
                kwargs['depth'] = opts[r'depth']
        wrappedextraprepare = extensions.wrappedfunction(exchange,
            '_pullbundle2extraprepare', pullbundle2extraprepare_widen)

    with wrappedextraprepare:
        return orig(ui, repo, *args, **opts)

def archivenarrowcmd(orig, ui, repo, *args, **opts):
    """Wraps archive command to narrow the default includes."""
    if repository.NARROW_REQUIREMENT in repo.requirements:
        repo_includes, repo_excludes = repo.narrowpats
        includes = set(opts.get(r'include', []))
        excludes = set(opts.get(r'exclude', []))
        includes, excludes, unused_invalid = narrowspec.restrictpatterns(
            includes, excludes, repo_includes, repo_excludes)
        if includes:
            opts[r'include'] = includes
        if excludes:
            opts[r'exclude'] = excludes
    return orig(ui, repo, *args, **opts)

def pullbundle2extraprepare(orig, pullop, kwargs):
    repo = pullop.repo
    if repository.NARROW_REQUIREMENT not in repo.requirements:
        return orig(pullop, kwargs)

    if narrowwirepeer.NARROWCAP not in pullop.remote.capabilities():
        raise error.Abort(_("server doesn't support narrow clones"))
    orig(pullop, kwargs)
    kwargs['narrow'] = True
    include, exclude = repo.narrowpats
    kwargs['oldincludepats'] = include
    kwargs['oldexcludepats'] = exclude
    kwargs['includepats'] = include
    kwargs['excludepats'] = exclude
    # calculate known nodes only in ellipses cases because in non-ellipses cases
    # we have all the nodes
    if narrowwirepeer.ELLIPSESCAP in pullop.remote.capabilities():
        kwargs['known'] = [node.hex(ctx.node()) for ctx in
                           repo.set('::%ln', pullop.common)
                           if ctx.node() != node.nullid]
        if not kwargs['known']:
            # Mercurial serializes an empty list as '' and deserializes it as
            # [''], so delete it instead to avoid handling the empty string on
            # the server.
            del kwargs['known']

extensions.wrapfunction(exchange,'_pullbundle2extraprepare',
                        pullbundle2extraprepare)

# This is an extension point for filesystems that need to do something other
# than just blindly unlink the files. It's not clear what arguments would be
# useful, so we're passing in a fair number of them, some of them redundant.
def _narrowcleanupwdir(repo, oldincludes, oldexcludes, newincludes, newexcludes,
                       oldmatch, newmatch):
    for f in repo.dirstate:
        if not newmatch(f):
            repo.dirstate.drop(f)
            repo.wvfs.unlinkpath(f)

def _narrow(ui, repo, remote, commoninc, oldincludes, oldexcludes,
            newincludes, newexcludes, force):
    oldmatch = narrowspec.match(repo.root, oldincludes, oldexcludes)
    newmatch = narrowspec.match(repo.root, newincludes, newexcludes)

    # This is essentially doing "hg outgoing" to find all local-only
    # commits. We will then check that the local-only commits don't
    # have any changes to files that will be untracked.
    unfi = repo.unfiltered()
    outgoing = discovery.findcommonoutgoing(unfi, remote,
                                            commoninc=commoninc)
    ui.status(_('looking for local changes to affected paths\n'))
    localnodes = []
    for n in itertools.chain(outgoing.missing, outgoing.excluded):
        if any(oldmatch(f) and not newmatch(f) for f in unfi[n].files()):
            localnodes.append(n)
    revstostrip = unfi.revs('descendants(%ln)', localnodes)
    hiddenrevs = repoview.filterrevs(repo, 'visible')
    visibletostrip = list(repo.changelog.node(r)
                          for r in (revstostrip - hiddenrevs))
    if visibletostrip:
        ui.status(_('The following changeset(s) or their ancestors have '
                    'local changes not on the remote:\n'))
        maxnodes = 10
        if ui.verbose or len(visibletostrip) <= maxnodes:
            for n in visibletostrip:
                ui.status('%s\n' % node.short(n))
        else:
            for n in visibletostrip[:maxnodes]:
                ui.status('%s\n' % node.short(n))
            ui.status(_('...and %d more, use --verbose to list all\n') %
                      (len(visibletostrip) - maxnodes))
        if not force:
            raise error.Abort(_('local changes found'),
                              hint=_('use --force-delete-local-changes to '
                                     'ignore'))

    with ui.uninterruptable():
        if revstostrip:
            tostrip = [unfi.changelog.node(r) for r in revstostrip]
            if repo['.'].node() in tostrip:
                # stripping working copy, so move to a different commit first
                urev = max(repo.revs('(::%n) - %ln + null',
                                     repo['.'].node(), visibletostrip))
                hg.clean(repo, urev)
            repair.strip(ui, unfi, tostrip, topic='narrow')

        todelete = []
        for f, f2, size in repo.store.datafiles():
            if f.startswith('data/'):
                file = f[5:-2]
                if not newmatch(file):
                    todelete.append(f)
            elif f.startswith('meta/'):
                dir = f[5:-13]
                dirs = ['.'] + sorted(util.dirs({dir})) + [dir]
                include = True
                for d in dirs:
                    visit = newmatch.visitdir(d)
                    if not visit:
                        include = False
                        break
                    if visit == 'all':
                        break
                if not include:
                    todelete.append(f)

        repo.destroying()

        with repo.transaction("narrowing"):
            for f in todelete:
                ui.status(_('deleting %s\n') % f)
                util.unlinkpath(repo.svfs.join(f))
                repo.store.markremoved(f)

            _narrowcleanupwdir(repo, oldincludes, oldexcludes, newincludes,
                               newexcludes, oldmatch, newmatch)
            repo.setnarrowpats(newincludes, newexcludes)

        repo.destroyed()

def _widen(ui, repo, remote, commoninc, newincludes, newexcludes):
    newmatch = narrowspec.match(repo.root, newincludes, newexcludes)

    def pullbundle2extraprepare_widen(orig, pullop, kwargs):
        orig(pullop, kwargs)
        # The old{in,ex}cludepats have already been set by orig()
        kwargs['includepats'] = newincludes
        kwargs['excludepats'] = newexcludes
        kwargs['widen'] = True
    wrappedextraprepare = extensions.wrappedfunction(exchange,
        '_pullbundle2extraprepare', pullbundle2extraprepare_widen)

    # define a function that narrowbundle2 can call after creating the
    # backup bundle, but before applying the bundle from the server
    def setnewnarrowpats():
        repo.setnarrowpats(newincludes, newexcludes)
    repo.setnewnarrowpats = setnewnarrowpats
    # silence the devel-warning of applying an empty changegroup
    overrides = {('devel', 'all-warnings'): False}

    with ui.uninterruptable():
        ds = repo.dirstate
        p1, p2 = ds.p1(), ds.p2()
        with ds.parentchange():
            ds.setparents(node.nullid, node.nullid)
        common = commoninc[0]
        with wrappedextraprepare, repo.ui.configoverride(overrides, 'widen'):
            exchange.pull(repo, remote, heads=common)
        with ds.parentchange():
            ds.setparents(p1, p2)

        repo.setnewnarrowpats()
        actions = {k: [] for k in 'a am f g cd dc r dm dg m e k p pr'.split()}
        addgaction = actions['g'].append

        mf = repo['.'].manifest().matches(newmatch)
        for f, fn in mf.iteritems():
            if f not in repo.dirstate:
                addgaction((f, (mf.flags(f), False),
                            "add from widened narrow clone"))

        merge.applyupdates(repo, actions, wctx=repo[None],
                           mctx=repo['.'], overwrite=False)
        merge.recordupdates(repo, actions, branchmerge=False)

# TODO(rdamazio): Make new matcher format and update description
@command('tracked',
    [('', 'addinclude', [], _('new paths to include')),
     ('', 'removeinclude', [], _('old paths to no longer include')),
     ('', 'addexclude', [], _('new paths to exclude')),
     ('', 'import-rules', '', _('import narrowspecs from a file')),
     ('', 'removeexclude', [], _('old paths to no longer exclude')),
     ('', 'clear', False, _('whether to replace the existing narrowspec')),
     ('', 'force-delete-local-changes', False,
       _('forces deletion of local changes when narrowing')),
    ] + commands.remoteopts,
    _('[OPTIONS]... [REMOTE]'),
    inferrepo=True)
def trackedcmd(ui, repo, remotepath=None, *pats, **opts):
    """show or change the current narrowspec

    With no argument, shows the current narrowspec entries, one per line. Each
    line will be prefixed with 'I' or 'X' for included or excluded patterns,
    respectively.

    The narrowspec is comprised of expressions to match remote files and/or
    directories that should be pulled into your client.
    The narrowspec has *include* and *exclude* expressions, with excludes always
    trumping includes: that is, if a file matches an exclude expression, it will
    be excluded even if it also matches an include expression.
    Excluding files that were never included has no effect.

    Each included or excluded entry is in the format described by
    'hg help patterns'.

    The options allow you to add or remove included and excluded expressions.

    If --clear is specified, then all previous includes and excludes are DROPPED
    and replaced by the new ones specified to --addinclude and --addexclude.
    If --clear is specified without any further options, the narrowspec will be
    empty and will not match any files.
    """
    opts = pycompat.byteskwargs(opts)
    if repository.NARROW_REQUIREMENT not in repo.requirements:
        ui.warn(_('The narrow command is only supported on respositories cloned'
                  ' with --narrow.\n'))
        return 1

    # Before supporting, decide whether it "hg tracked --clear" should mean
    # tracking no paths or all paths.
    if opts['clear']:
        ui.warn(_('The --clear option is not yet supported.\n'))
        return 1

    # import rules from a file
    newrules = opts.get('import_rules')
    if newrules:
        try:
            filepath = os.path.join(pycompat.getcwd(), newrules)
            fdata = util.readfile(filepath)
        except IOError as inst:
            raise error.Abort(_("cannot read narrowspecs from '%s': %s") %
                              (filepath, encoding.strtolocal(inst.strerror)))
        includepats, excludepats, profiles = sparse.parseconfig(ui, fdata,
                                                                'narrow')
        if profiles:
            raise error.Abort(_("including other spec files using '%include' "
                                "is not supported in narrowspec"))
        opts['addinclude'].extend(includepats)
        opts['addexclude'].extend(excludepats)

    addedincludes = narrowspec.parsepatterns(opts['addinclude'])
    removedincludes = narrowspec.parsepatterns(opts['removeinclude'])
    addedexcludes = narrowspec.parsepatterns(opts['addexclude'])
    removedexcludes = narrowspec.parsepatterns(opts['removeexclude'])
    widening = addedincludes or removedexcludes
    narrowing = removedincludes or addedexcludes
    only_show = not widening and not narrowing

    # Only print the current narrowspec.
    if only_show:
        include, exclude = repo.narrowpats

        ui.pager('tracked')
        fm = ui.formatter('narrow', opts)
        for i in sorted(include):
            fm.startitem()
            fm.write('status', '%s ', 'I', label='narrow.included')
            fm.write('pat', '%s\n', i, label='narrow.included')
        for i in sorted(exclude):
            fm.startitem()
            fm.write('status', '%s ', 'X', label='narrow.excluded')
            fm.write('pat', '%s\n', i, label='narrow.excluded')
        fm.end()
        return 0

    with repo.wlock(), repo.lock():
        cmdutil.bailifchanged(repo)

        # Find the revisions we have in common with the remote. These will
        # be used for finding local-only changes for narrowing. They will
        # also define the set of revisions to update for widening.
        remotepath = ui.expandpath(remotepath or 'default')
        url, branches = hg.parseurl(remotepath)
        ui.status(_('comparing with %s\n') % util.hidepassword(url))
        remote = hg.peer(repo, opts, url)
        commoninc = discovery.findcommonincoming(repo, remote)

        oldincludes, oldexcludes = repo.narrowpats
        if narrowing:
            newincludes = oldincludes - removedincludes
            newexcludes = oldexcludes | addedexcludes
            _narrow(ui, repo, remote, commoninc, oldincludes, oldexcludes,
                    newincludes, newexcludes,
                    opts['force_delete_local_changes'])
            # _narrow() updated the narrowspec and _widen() below needs to
            # use the updated values as its base (otherwise removed includes
            # and addedexcludes will be lost in the resulting narrowspec)
            oldincludes = newincludes
            oldexcludes = newexcludes

        if widening:
            newincludes = oldincludes | addedincludes
            newexcludes = oldexcludes - removedexcludes
            _widen(ui, repo, remote, commoninc, newincludes, newexcludes)

    return 0