Initial directory restructuring to clarify dependencies

1 files changed, 941 insertions, 0 deletions

diff --git a/libbe/storage/vcs/base.py b/libbe/storage/vcs/base.py
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+++ b/libbe/storage/vcs/base.py
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+# Copyright (C) 2005-2009 Aaron Bentley and Panometrics, Inc.
+#                         Alexander Belchenko <bialix@ukr.net>
+#                         Ben Finney <benf@cybersource.com.au>
+#                         Chris Ball <cjb@laptop.org>
+#                         Gianluca Montecchi <gian@grys.it>
+#                         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.
+"""
+
+import codecs
+import os
+import os.path
+import re
+from socket import gethostname
+import shutil
+import sys
+import tempfile
+
+import libbe
+from utility import Dir, search_parent_directories
+from subproc import CommandError, invoke
+from plugin import get_plugin
+
+if libbe.TESTING == True:
+    import unittest
+    import doctest
+
+
+# List VCS modules in order of preference.
+# Don't list this module, it is implicitly last.
+VCS_ORDER = ['arch', 'bzr', 'darcs', 'git', 'hg']
+
+def set_preferred_vcs(name):
+    global VCS_ORDER
+    assert name in VCS_ORDER, \
+        'unrecognized VCS %s not in\n  %s' % (name, VCS_ORDER)
+    VCS_ORDER.remove(name)
+    VCS_ORDER.insert(0, name)
+
+def _get_matching_vcs(matchfn):
+    """Return the first module for which matchfn(VCS_instance) is true"""
+    for submodname in VCS_ORDER:
+        module = get_plugin('libbe', submodname)
+        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 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
+    def __str__(self):
+        return "<%s %s>" % (self.__class__.__name__, id(self))
+    def __repr__(self):
+        return str(self)
+    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 version(self):
+        """Cache version string for efficiency."""
+        if not hasattr(self, '_version'):
+            self._version = self._get_version()
+        return self._version
+    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.
+
+        allow_no_vcs==True allows direct access to files through
+        codecs.open() or open() if the vcs decides it can't handle the
+        given path.
+        """
+        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:
+            if binary == True:
+                f = codecs.open(path, "r", self.encoding)
+            else:
+                f = open(path, "rb")
+            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, **kwargs):
+        if 'cwd' not in kwargs:
+            kwargs['cwd'] = self.rootdir
+        if 'verbose' not in kwargs:
+            kwargs['verbose'] = self.verboseInvoke
+        if 'encoding' not in kwargs:
+            kwargs['encoding'] = self.encoding
+        return invoke(*args, **kwargs)
+    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)
+        
+
+if libbe.TESTING == True:
+    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()])