path: root/libbe/vcs.py

# Copyright (C) 2005-2009 Aaron Bentley and Panometrics, Inc.
#                         Alexander Belchenko <bialix@ukr.net>
#                         Ben Finney <ben+python@benfinney.id.au>
#                         Chris Ball <cjb@laptop.org>
#                         W. Trevor King <wking@drexel.edu>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

"""
Define the base VCS (Version Control System) class, which should be
subclassed by other Version Control System backends.  The base class
implements a "do not version" VCS.
"""

from subprocess import Popen, PIPE
import codecs
import os
import os.path
import re
from socket import gethostname
import shutil
import sys
import tempfile
import unittest
import doctest

from utility import Dir, search_parent_directories


def _get_matching_vcs(matchfn):
    """Return the first module for which matchfn(VCS_instance) is true"""
    import arch
    import bzr
    import darcs
    import git
    import hg
    for module in [arch, bzr, darcs, git, hg]:
        vcs = module.new()
        if matchfn(vcs) == True:
            return vcs
        vcs.cleanup()
    return VCS()
    
def vcs_by_name(vcs_name):
    """Return the module for the VCS with the given name"""
    return _get_matching_vcs(lambda vcs: vcs.name == vcs_name)

def detect_vcs(dir):
    """Return an VCS instance for the vcs being used in this directory"""
    return _get_matching_vcs(lambda vcs: vcs.detect(dir))

def installed_vcs():
    """Return an instance of an installed VCS"""
    return _get_matching_vcs(lambda vcs: vcs.installed())


class CommandError(Exception):
    def __init__(self, command, status, stdout, stderr):
        strerror = ["Command failed (%d):\n  %s\n" % (status, stderr),
                    "while executing\n  %s" % command]
        Exception.__init__(self, "\n".join(strerror))
        self.command = command
        self.status = status
        self.stdout = stdout
        self.stderr = stderr

class SettingIDnotSupported(NotImplementedError):
    pass

class VCSnotRooted(Exception):
    def __init__(self):
        msg = "VCS not rooted"
        Exception.__init__(self, msg)

class PathNotInRoot(Exception):
    def __init__(self, path, root):
        msg = "Path '%s' not in root '%s'" % (path, root)
        Exception.__init__(self, msg)
        self.path = path
        self.root = root

class NoSuchFile(Exception):
    def __init__(self, pathname, root="."):
        path = os.path.abspath(os.path.join(root, pathname))
        Exception.__init__(self, "No such file: %s" % path)

class EmptyCommit(Exception):
    def __init__(self):
        Exception.__init__(self, "No changes to commit")


def new():
    return VCS()

class VCS(object):
    """
    This class implements a 'no-vcs' interface.

    Support for other VCSs can be added by subclassing this class, and
    overriding methods _vcs_*() with code appropriate for your VCS.
    
    The methods _u_*() are utility methods available to the _vcs_*()
    methods.
    """
    name = "None"
    client = "" # command-line tool for _u_invoke_client
    versioned = False
    def __init__(self, paranoid=False, encoding=sys.getdefaultencoding()):
        self.paranoid = paranoid
        self.verboseInvoke = False
        self.rootdir = None
        self._duplicateBasedir = None
        self._duplicateDirname = None
        self.encoding = encoding
        self.version = self._get_version()
    def _vcs_version(self):
        """
        Return the VCS version string.
        """
        return "0.0"
    def _vcs_detect(self, path=None):
        """
        Detect whether a directory is revision controlled with this VCS.
        """
        return True
    def _vcs_root(self, path):
        """
        Get the VCS root.  This is the default working directory for
        future invocations.  You would normally set this to the root
        directory for your VCS.
        """
        if os.path.isdir(path)==False:
            path = os.path.dirname(path)
            if path == "":
                path = os.path.abspath(".")
        return path
    def _vcs_init(self, path):
        """
        Begin versioning the tree based at path.
        """
        pass
    def _vcs_cleanup(self):
        """
        Remove any cruft that _vcs_init() created outside of the
        versioned tree.
        """
        pass
    def _vcs_get_user_id(self):
        """
        Get the VCS's suggested user id (e.g. "John Doe <jdoe@example.com>").
        If the VCS has not been configured with a username, return None.
        """
        return None
    def _vcs_set_user_id(self, value):
        """
        Set the VCS's suggested user id (e.g "John Doe <jdoe@example.com>").
        This is run if the VCS has not been configured with a usename, so
        that commits will have a reasonable FROM value.
        """
        raise SettingIDnotSupported
    def _vcs_add(self, path):
        """
        Add the already created file at path to version control.
        """
        pass
    def _vcs_remove(self, path):
        """
        Remove the file at path from version control.  Optionally
        remove the file from the filesystem as well.
        """
        pass
    def _vcs_update(self, path):
        """
        Notify the versioning system of changes to the versioned file
        at path.
        """
        pass
    def _vcs_get_file_contents(self, path, revision=None, binary=False):
        """
        Get the file contents as they were in a given revision.
        Revision==None specifies the current revision.
        """
        assert revision == None, \
            "The %s VCS does not support revision specifiers" % self.name
        if binary == False:
            f = codecs.open(os.path.join(self.rootdir, path), "r", self.encoding)
        else:
            f = open(os.path.join(self.rootdir, path), "rb")
        contents = f.read()
        f.close()
        return contents
    def _vcs_duplicate_repo(self, directory, revision=None):
        """
        Get the repository as it was in a given revision.
        revision==None specifies the current revision.
        dir specifies a directory to create the duplicate in.
        """
        shutil.copytree(self.rootdir, directory, True)
    def _vcs_commit(self, commitfile, allow_empty=False):
        """
        Commit the current working directory, using the contents of
        commitfile as the comment.  Return the name of the old
        revision (or None if commits are not supported).
        
        If allow_empty == False, raise EmptyCommit if there are no
        changes to commit.
        """
        return None
    def _vcs_revision_id(self, index):
        """
        Return the name of the <index>th revision.  Index will be an
        integer (possibly <= 0).  The choice of which branch to follow
        when crossing branches/merges is not defined.

        Return None if revision IDs are not supported, or if the
        specified revision does not exist.
        """
        return None
    def _get_version(self):
        try:
            ret = self._vcs_version()
            return ret
        except OSError, e:
            if e.errno == errno.ENOENT:
                return None
            else:
                raise OSError, e
        except CommandError:
            return None
    def installed(self):
        if self.version != None:
            return True
        return False
    def detect(self, path="."):
        """
        Detect whether a directory is revision controlled with this VCS.
        """
        return self._vcs_detect(path)
    def root(self, path):
        """
        Set the root directory to the path's VCS root.  This is the
        default working directory for future invocations.
        """
        self.rootdir = self._vcs_root(path)
    def init(self, path):
        """
        Begin versioning the tree based at path.
        Also roots the vcs at path.
        """
        if os.path.isdir(path)==False:
            path = os.path.dirname(path)
        self._vcs_init(path)
        self.root(path)
    def cleanup(self):
        self._vcs_cleanup()
    def get_user_id(self):
        """
        Get the VCS's suggested user id (e.g. "John Doe <jdoe@example.com>").
        If the VCS has not been configured with a username, return the user's
        id.  You can override the automatic lookup procedure by setting the
        VCS.user_id attribute to a string of your choice.
        """
        if hasattr(self, "user_id"):
            if self.user_id != None:
                return self.user_id
        id = self._vcs_get_user_id()
        if id == None:
            name = self._u_get_fallback_username()
            email = self._u_get_fallback_email()
            id = self._u_create_id(name, email)
            print >> sys.stderr, "Guessing id '%s'" % id
            try:
                self.set_user_id(id)
            except SettingIDnotSupported:
                pass
        return id
    def set_user_id(self, value):
        """
        Set the VCS's suggested user id (e.g "John Doe <jdoe@example.com>").
        This is run if the VCS has not been configured with a usename, so
        that commits will have a reasonable FROM value.
        """
        self._vcs_set_user_id(value)
    def add(self, path):
        """
        Add the already created file at path to version control.
        """
        self._vcs_add(self._u_rel_path(path))
    def remove(self, path):
        """
        Remove a file from both version control and the filesystem.
        """
        self._vcs_remove(self._u_rel_path(path))
        if os.path.exists(path):
            os.remove(path)
    def recursive_remove(self, dirname):
        """
        Remove a file/directory and all its decendents from both
        version control and the filesystem.
        """
        if not os.path.exists(dirname):
            raise NoSuchFile(dirname)
        for dirpath,dirnames,filenames in os.walk(dirname, topdown=False):
            filenames.extend(dirnames)
            for path in filenames:
                fullpath = os.path.join(dirpath, path)
                if os.path.exists(fullpath) == False:
                    continue
                self._vcs_remove(self._u_rel_path(fullpath))
        if os.path.exists(dirname):
            shutil.rmtree(dirname)
    def update(self, path):
        """
        Notify the versioning system of changes to the versioned file
        at path.
        """
        self._vcs_update(self._u_rel_path(path))
    def get_file_contents(self, path, revision=None, allow_no_vcs=False, binary=False):
        """
        Get the file as it was in a given revision.
        Revision==None specifies the current revision.
        """
        if not os.path.exists(path):
            raise NoSuchFile(path)
        if self._use_vcs(path, allow_no_vcs):
            relpath = self._u_rel_path(path)
            contents = self._vcs_get_file_contents(relpath,revision,binary=binary)
        else:
            f = codecs.open(path, "r", self.encoding)
            contents = f.read()
            f.close()
        return contents
    def set_file_contents(self, path, contents, allow_no_vcs=False, binary=False):
        """
        Set the file contents under version control.
        """
        add = not os.path.exists(path)
        if binary == False:
            f = codecs.open(path, "w", self.encoding)
        else:
            f = open(path, "wb")
        f.write(contents)
        f.close()
        
        if self._use_vcs(path, allow_no_vcs):
            if add:
                self.add(path)
            else:
                self.update(path)
    def mkdir(self, path, allow_no_vcs=False, check_parents=True):
        """
        Create (if neccessary) a directory at path under version
        control.
        """
        if check_parents == True:
            parent = os.path.dirname(path)
            if not os.path.exists(parent): # recurse through parents
                self.mkdir(parent, allow_no_vcs, check_parents)
        if not os.path.exists(path):
            os.mkdir(path)
            if self._use_vcs(path, allow_no_vcs):
                self.add(path)
        else:
            assert os.path.isdir(path)
            if self._use_vcs(path, allow_no_vcs):
                #self.update(path)# Don't update directories.  Changing files
                pass              # underneath them should be sufficient.
                
    def duplicate_repo(self, revision=None):
        """
        Get the repository as it was in a given revision.
        revision==None specifies the current revision.
        Return the path to the arbitrary directory at the base of the new repo.
        """
        # Dirname in Basedir to protect against simlink attacks.
        if self._duplicateBasedir == None:
            self._duplicateBasedir = tempfile.mkdtemp(prefix='BEvcs')
            self._duplicateDirname = \
                os.path.join(self._duplicateBasedir, "duplicate")
            self._vcs_duplicate_repo(directory=self._duplicateDirname,
                                     revision=revision)
        return self._duplicateDirname
    def remove_duplicate_repo(self):
        """
        Clean up a duplicate repo created with duplicate_repo().
        """
        if self._duplicateBasedir != None:
            shutil.rmtree(self._duplicateBasedir)
            self._duplicateBasedir = None
            self._duplicateDirname = None
    def commit(self, summary, body=None, allow_empty=False):
        """
        Commit the current working directory, with a commit message
        string summary and body.  Return the name of the old revision
        (or None if versioning is not supported).
        
        If allow_empty == False (the default), raise EmptyCommit if
        there are no changes to commit.
        """
        summary = summary.strip()+'\n'
        if body is not None:
            summary += '\n' + body.strip() + '\n'
        descriptor, filename = tempfile.mkstemp()
        revision = None
        try:
            temp_file = os.fdopen(descriptor, 'wb')
            temp_file.write(summary)
            temp_file.flush()
            self.precommit()
            revision = self._vcs_commit(filename, allow_empty=allow_empty)
            temp_file.close()
            self.postcommit()
        finally:
            os.remove(filename)
        return revision
    def precommit(self):
        """
        Executed before all attempted commits.
        """
        pass
    def postcommit(self):
        """
        Only executed after successful commits.
        """
        pass
    def revision_id(self, index=None):
        """
        Return the name of the <index>th revision.  The choice of
        which branch to follow when crossing branches/merges is not
        defined.

        Return None if index==None, revision IDs are not supported, or
        if the specified revision does not exist.
        """
        if index == None:
            return None
        return self._vcs_revision_id(index)
    def _u_any_in_string(self, list, string):
        """
        Return True if any of the strings in list are in string.
        Otherwise return False.
        """
        for list_string in list:
            if list_string in string:
                return True
        return False
    def _u_invoke(self, args, stdin=None, expect=(0,), cwd=None,
                  unicode_output=True):
        """
        expect should be a tuple of allowed exit codes.  cwd should be
        the directory from which the command will be executed.  When
        unicode_output == True, convert stdout and stdin strings to
        unicode before returing them.
        """
        if cwd == None:
            cwd = self.rootdir
        if self.verboseInvoke == True:
            print >> sys.stderr, "%s$ %s" % (cwd, " ".join(args))
        try :
            if sys.platform != "win32":
                q = Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE, cwd=cwd)
            else:
                # win32 don't have os.execvp() so have to run command in a shell
                q = Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE, 
                          shell=True, cwd=cwd)
        except OSError, e :
            raise CommandError(args, status=e.args[0], stdout="", stderr=e)
        stdout,stderr = q.communicate(input=stdin)
        status = q.wait()
        if unicode_output == True:
            stdout = unicode(stdout, self.encoding)
            stderr = unicode(stderr, self.encoding)
        if self.verboseInvoke == True:
            print >> sys.stderr, "%d\n%s%s" % (status, stdout, stderr)
        if status not in expect:
            raise CommandError(args, status, stdout, stderr)
        return status, stdout, stderr
    def _u_invoke_client(self, *args, **kwargs):
        cl_args = [self.client]
        cl_args.extend(args)
        return self._u_invoke(cl_args, **kwargs)
    def _u_search_parent_directories(self, path, filename):
        """
        Find the file (or directory) named filename in path or in any
        of path's parents.
        
        e.g.
          search_parent_directories("/a/b/c", ".be")
        will return the path to the first existing file from
          /a/b/c/.be
          /a/b/.be
          /a/.be
          /.be
        or None if none of those files exist.
        """
        return search_parent_directories(path, filename)
    def _use_vcs(self, path, allow_no_vcs):
        """
        Try and decide if _vcs_add/update/mkdir/etc calls will
        succeed.  Returns True is we think the vcs_call would
        succeeed, and False otherwise.
        """
        use_vcs = True
        exception = None
        if self.rootdir != None:
            if self.path_in_root(path) == False:
                use_vcs = False
                exception = PathNotInRoot(path, self.rootdir)
        else:
            use_vcs = False
            exception = VCSnotRooted
        if use_vcs == False and allow_no_vcs==False:
            raise exception
        return use_vcs
    def path_in_root(self, path, root=None):
        """
        Return the relative path to path from root.
        >>> vcs = new()
        >>> vcs.path_in_root("/a.b/c/.be", "/a.b/c")
        True
        >>> vcs.path_in_root("/a.b/.be", "/a.b/c")
        False
        """
        if root == None:
            if self.rootdir == None:
                raise VCSnotRooted
            root = self.rootdir
        path = os.path.abspath(path)
        absRoot = os.path.abspath(root)
        absRootSlashedDir = os.path.join(absRoot,"")
        if not path.startswith(absRootSlashedDir):
            return False
        return True
    def _u_rel_path(self, path, root=None):
        """
        Return the relative path to path from root.
        >>> vcs = new()
        >>> vcs._u_rel_path("/a.b/c/.be", "/a.b/c")
        '.be'
        """
        if root == None:
            if self.rootdir == None:
                raise VCSnotRooted
            root = self.rootdir
        path = os.path.abspath(path)
        absRoot = os.path.abspath(root)
        absRootSlashedDir = os.path.join(absRoot,"")
        if not path.startswith(absRootSlashedDir):
            raise PathNotInRoot(path, absRootSlashedDir)
        assert path != absRootSlashedDir, \
            "file %s == root directory %s" % (path, absRootSlashedDir)
        relpath = path[len(absRootSlashedDir):]
        return relpath
    def _u_abspath(self, path, root=None):
        """
        Return the absolute path from a path realtive to root.
        >>> vcs = new()
        >>> vcs._u_abspath(".be", "/a.b/c")
        '/a.b/c/.be'
        """
        if root == None:
            assert self.rootdir != None, "VCS not rooted"
            root = self.rootdir
        return os.path.abspath(os.path.join(root, path))
    def _u_create_id(self, name, email=None):
        """
        >>> vcs = new()
        >>> vcs._u_create_id("John Doe", "jdoe@example.com")
        'John Doe <jdoe@example.com>'
        >>> vcs._u_create_id("John Doe")
        'John Doe'
        """
        assert len(name) > 0
        if email == None or len(email) == 0:
            return name
        else:
            return "%s <%s>" % (name, email)
    def _u_parse_id(self, value):
        """
        >>> vcs = new()
        >>> vcs._u_parse_id("John Doe <jdoe@example.com>")
        ('John Doe', 'jdoe@example.com')
        >>> vcs._u_parse_id("John Doe")
        ('John Doe', None)
        >>> try:
        ...     vcs._u_parse_id("John Doe <jdoe@example.com><what?>")
        ... except AssertionError:
        ...     print "Invalid match"
        Invalid match
        """
        emailexp = re.compile("(.*) <([^>]*)>(.*)")
        match = emailexp.search(value)
        if match == None:
            email = None
            name = value
        else:
            assert len(match.groups()) == 3
            assert match.groups()[2] == "", match.groups()
            email = match.groups()[1]
            name = match.groups()[0]
        assert name != None
        assert len(name) > 0
        return (name, email)
    def _u_get_fallback_username(self):
        name = None
        for envariable in ["LOGNAME", "USERNAME"]:
            if os.environ.has_key(envariable):
                name = os.environ[envariable]
                break
        assert name != None
        return name
    def _u_get_fallback_email(self):
        hostname = gethostname()
        name = self._u_get_fallback_username()
        return "%s@%s" % (name, hostname)
    def _u_parse_commitfile(self, commitfile):
        """
        Split the commitfile created in self.commit() back into
        summary and header lines.
        """
        f = codecs.open(commitfile, "r", self.encoding)
        summary = f.readline()
        body = f.read()
        body.lstrip('\n')
        if len(body) == 0:
            body = None
        f.close()
        return (summary, body)
        

def setup_vcs_test_fixtures(testcase):
    """Set up test fixtures for VCS test case."""
    testcase.vcs = testcase.Class()
    testcase.dir = Dir()
    testcase.dirname = testcase.dir.path

    vcs_not_supporting_uninitialized_user_id = []
    vcs_not_supporting_set_user_id = ["None", "hg"]
    testcase.vcs_supports_uninitialized_user_id = (
        testcase.vcs.name not in vcs_not_supporting_uninitialized_user_id)
    testcase.vcs_supports_set_user_id = (
        testcase.vcs.name not in vcs_not_supporting_set_user_id)

    if not testcase.vcs.installed():
        testcase.fail(
            "%(name)s VCS not found" % vars(testcase.Class))

    if testcase.Class.name != "None":
        testcase.failIf(
            testcase.vcs.detect(testcase.dirname),
            "Detected %(name)s VCS before initialising"
                % vars(testcase.Class))

    testcase.vcs.init(testcase.dirname)


class VCSTestCase(unittest.TestCase):
    """Test cases for base VCS class."""

    Class = VCS

    def __init__(self, *args, **kwargs):
        super(VCSTestCase, self).__init__(*args, **kwargs)
        self.dirname = None

    def setUp(self):
        super(VCSTestCase, self).setUp()
        setup_vcs_test_fixtures(self)

    def tearDown(self):
        self.vcs.cleanup()
        self.dir.cleanup()
        super(VCSTestCase, self).tearDown()

    def full_path(self, rel_path):
        return os.path.join(self.dirname, rel_path)


class VCS_init_TestCase(VCSTestCase):
    """Test cases for VCS.init method."""

    def test_detect_should_succeed_after_init(self):
        """Should detect VCS in directory after initialization."""
        self.failUnless(
            self.vcs.detect(self.dirname),
            "Did not detect %(name)s VCS after initialising"
                % vars(self.Class))

    def test_vcs_rootdir_in_specified_root_path(self):
        """VCS root directory should be in specified root path."""
        rp = os.path.realpath(self.vcs.rootdir)
        dp = os.path.realpath(self.dirname)
        vcs_name = self.Class.name
        self.failUnless(
            dp == rp or rp == None,
            "%(vcs_name)s VCS root in wrong dir (%(dp)s %(rp)s)" % vars())


class VCS_get_user_id_TestCase(VCSTestCase):
    """Test cases for VCS.get_user_id method."""

    def test_gets_existing_user_id(self):
        """Should get the existing user ID."""
        if not self.vcs_supports_uninitialized_user_id:
            return

        user_id = self.vcs.get_user_id()
        self.failUnless(
            user_id is not None,
            "unable to get a user id")


class VCS_set_user_id_TestCase(VCSTestCase):
    """Test cases for VCS.set_user_id method."""

    def setUp(self):
        super(VCS_set_user_id_TestCase, self).setUp()

        if self.vcs_supports_uninitialized_user_id:
            self.prev_user_id = self.vcs.get_user_id()
        else:
            self.prev_user_id = "Uninitialized identity <bogus@example.org>"

        if self.vcs_supports_set_user_id:
            self.test_new_user_id = "John Doe <jdoe@example.com>"
            self.vcs.set_user_id(self.test_new_user_id)

    def tearDown(self):
        if self.vcs_supports_set_user_id:
            self.vcs.set_user_id(self.prev_user_id)
        super(VCS_set_user_id_TestCase, self).tearDown()

    def test_raises_error_in_unsupported_vcs(self):
        """Should raise an error in a VCS that doesn't support it."""
        if self.vcs_supports_set_user_id:
            return
        self.assertRaises(
            SettingIDnotSupported,
            self.vcs.set_user_id, "foo")

    def test_updates_user_id_in_supporting_vcs(self):
        """Should update the user ID in an VCS that supports it."""
        if not self.vcs_supports_set_user_id:
            return
        user_id = self.vcs.get_user_id()
        self.failUnlessEqual(
            self.test_new_user_id, user_id,
            "user id not set correctly (expected %s, got %s)"
                % (self.test_new_user_id, user_id))


def setup_vcs_revision_test_fixtures(testcase):
    """Set up revision test fixtures for VCS test case."""
    testcase.test_dirs = ['a', 'a/b', 'c']
    for path in testcase.test_dirs:
        testcase.vcs.mkdir(testcase.full_path(path))

    testcase.test_files = ['a/text', 'a/b/text']

    testcase.test_contents = {
        'rev_1': "Lorem ipsum",
        'uncommitted': "dolor sit amet",
        }


class VCS_mkdir_TestCase(VCSTestCase):
    """Test cases for VCS.mkdir method."""

    def setUp(self):
        super(VCS_mkdir_TestCase, self).setUp()
        setup_vcs_revision_test_fixtures(self)

    def tearDown(self):
        for path in reversed(sorted(self.test_dirs)):
            self.vcs.recursive_remove(self.full_path(path))
        super(VCS_mkdir_TestCase, self).tearDown()

    def test_mkdir_creates_directory(self):
        """Should create specified directory in filesystem."""
        for path in self.test_dirs:
            full_path = self.full_path(path)
            self.failUnless(
                os.path.exists(full_path),
                "path %(full_path)s does not exist" % vars())


class VCS_commit_TestCase(VCSTestCase):
    """Test cases for VCS.commit method."""

    def setUp(self):
        super(VCS_commit_TestCase, self).setUp()
        setup_vcs_revision_test_fixtures(self)

    def tearDown(self):
        for path in reversed(sorted(self.test_dirs)):
            self.vcs.recursive_remove(self.full_path(path))
        super(VCS_commit_TestCase, self).tearDown()

    def test_file_contents_as_specified(self):
        """Should set file contents as specified."""
        test_contents = self.test_contents['rev_1']
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(full_path, test_contents)
            current_contents = self.vcs.get_file_contents(full_path)
            self.failUnlessEqual(test_contents, current_contents)

    def test_file_contents_as_committed(self):
        """Should have file contents as specified after commit."""
        test_contents = self.test_contents['rev_1']
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(full_path, test_contents)
            revision = self.vcs.commit("Initial file contents.")
            current_contents = self.vcs.get_file_contents(full_path)
            self.failUnlessEqual(test_contents, current_contents)

    def test_file_contents_as_set_when_uncommitted(self):
        """Should set file contents as specified after commit."""
        if not self.vcs.versioned:
            return
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(
                full_path, self.test_contents['rev_1'])
            revision = self.vcs.commit("Initial file contents.")
            self.vcs.set_file_contents(
                full_path, self.test_contents['uncommitted'])
            current_contents = self.vcs.get_file_contents(full_path)
            self.failUnlessEqual(
                self.test_contents['uncommitted'], current_contents)

    def test_revision_file_contents_as_committed(self):
        """Should get file contents as committed to specified revision."""
        if not self.vcs.versioned:
            return
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(
                full_path, self.test_contents['rev_1'])
            revision = self.vcs.commit("Initial file contents.")
            self.vcs.set_file_contents(
                full_path, self.test_contents['uncommitted'])
            committed_contents = self.vcs.get_file_contents(
                full_path, revision)
            self.failUnlessEqual(
                self.test_contents['rev_1'], committed_contents)

    def test_revision_id_as_committed(self):
        """Check for compatibility between .commit() and .revision_id()"""
        if not self.vcs.versioned:
            self.failUnlessEqual(self.vcs.revision_id(5), None)
            return
        committed_revisions = []
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(
                full_path, self.test_contents['rev_1'])
            revision = self.vcs.commit("Initial %s contents." % path)
            committed_revisions.append(revision)
            self.vcs.set_file_contents(
                full_path, self.test_contents['uncommitted'])
            revision = self.vcs.commit("Altered %s contents." % path)
            committed_revisions.append(revision)
        for i,revision in enumerate(committed_revisions):
            self.failUnlessEqual(self.vcs.revision_id(i), revision)
            i += -len(committed_revisions) # check negative indices
            self.failUnlessEqual(self.vcs.revision_id(i), revision)
        i = len(committed_revisions)
        self.failUnlessEqual(self.vcs.revision_id(i), None)
        self.failUnlessEqual(self.vcs.revision_id(-i-1), None)

    def test_revision_id_as_committed(self):
        """Check revision id before first commit"""
        if not self.vcs.versioned:
            self.failUnlessEqual(self.vcs.revision_id(5), None)
            return
        committed_revisions = []
        for path in self.test_files:
            self.failUnlessEqual(self.vcs.revision_id(0), None)


class VCS_duplicate_repo_TestCase(VCSTestCase):
    """Test cases for VCS.duplicate_repo method."""

    def setUp(self):
        super(VCS_duplicate_repo_TestCase, self).setUp()
        setup_vcs_revision_test_fixtures(self)

    def tearDown(self):
        self.vcs.remove_duplicate_repo()
        for path in reversed(sorted(self.test_dirs)):
            self.vcs.recursive_remove(self.full_path(path))
        super(VCS_duplicate_repo_TestCase, self).tearDown()

    def test_revision_file_contents_as_committed(self):
        """Should match file contents as committed to specified revision."""
        if not self.vcs.versioned:
            return
        for path in self.test_files:
            full_path = self.full_path(path)
            self.vcs.set_file_contents(
                full_path, self.test_contents['rev_1'])
            revision = self.vcs.commit("Commit current status")
            self.vcs.set_file_contents(
                full_path, self.test_contents['uncommitted'])
            dup_repo_path = self.vcs.duplicate_repo(revision)
            dup_file_path = os.path.join(dup_repo_path, path)
            dup_file_contents = file(dup_file_path, 'rb').read()
            self.failUnlessEqual(
                self.test_contents['rev_1'], dup_file_contents)
            self.vcs.remove_duplicate_repo()


def make_vcs_testcase_subclasses(vcs_class, namespace):
    """Make VCSTestCase subclasses for vcs_class in the namespace."""
    vcs_testcase_classes = [
        c for c in (
            ob for ob in globals().values() if isinstance(ob, type))
        if issubclass(c, VCSTestCase)]

    for base_class in vcs_testcase_classes:
        testcase_class_name = vcs_class.__name__ + base_class.__name__
        testcase_class_bases = (base_class,)
        testcase_class_dict = dict(base_class.__dict__)
        testcase_class_dict['Class'] = vcs_class
        testcase_class = type(
            testcase_class_name, testcase_class_bases, testcase_class_dict)
        setattr(namespace, testcase_class_name, testcase_class)


unitsuite = unittest.TestLoader().loadTestsFromModule(sys.modules[__name__])
suite = unittest.TestSuite([unitsuite, doctest.DocTestSuite()])