~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2010 Canonical Ltd

#

# 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

"""Tests for how many modules are loaded in executing various commands."""

from testtools import content

from bzrlib.plugin import (

    are_plugins_disabled,

    )

from bzrlib.tests import (

    TestCaseWithTransport,

    )

class TestImportTariffs(TestCaseWithTransport):

    """Check how many modules are loaded for some representative scenarios.

    See the Testing Guide in the developer documentation for more explanation.

    """

    def run_command_check_imports(self, args, forbidden_imports):

        """Run bzr ARGS in a subprocess and check its imports.

        This is fairly expensive because we start a subprocess, so we aim to

        cover representative rather than exhaustive cases.

        :param forbidden_imports: List of fully-qualified Python module names

            that should not be loaded while running this command.

        """

        # We use PYTHON_VERBOSE rather than --profile-importts because in

        # experimentation the profile-imports output seems to not always show

        # the modules you'd expect; this can be debugged but python -v seems

        # more likely to always show everything.  And we use the environment

        # variable rather than 'python -v' in the hope it will work even if

        # bzr is frozen and python is not explicitly specified. -- mbp 20100208

        #

        # Normally we want test isolation from the real $HOME but here we

        # explicitly do want to test against things installed there, therefore

        # we pass it through.

        env_changes = dict(PYTHONVERBOSE='1')

        for name in ['BZR_HOME', 'BZR_PLUGIN_PATH', 'HOME',]:

            env_changes[name] = self._old_env.get(name)

        out, err = self.run_bzr_subprocess(args,

            allow_plugins=(not are_plugins_disabled()),

            env_changes=env_changes)

        self.addDetail('subprocess_stderr', 

            content.Content(content.ContentType("text", "plain"),

                lambda:[err]))

        bad_modules = []

        for module_name in forbidden_imports:

            if err.find("\nimport %s " % module_name) != -1:

                bad_modules.append(module_name)

        if bad_modules:

            self.fail("command %r loaded forbidden modules %r" 

                % (args, bad_modules))

        return out, err

    def test_import_tariffs_working(self):

        # check some guaranteed-true and false imports to be sure we're

        # measuring correctly

        self.make_branch_and_tree('.')

        self.run_command_check_imports(['st'],

            ['nonexistentmodulename', 'anothernonexistentmodule'])

        self.assertRaises(AssertionError,

            self.run_command_check_imports,

            ['st'],

            ['bzrlib.tree'])

    def test_simple_local(self):

        # 'st' in a working tree shouldn't need many modules

        self.make_branch_and_tree('.')

        self.run_command_check_imports(['st'], [

            'bzrlib.bundle.commands',

            'bzrlib.cmd_version_info',

            'bzrlib.foreign',

            'bzrlib.remote',

            'bzrlib.sign_my_commits',

            'bzrlib.smart',

            'smtplib',

            'tarfile',

            ])

        # TODO: similar test for repository-only operations, checking we avoid

        # loading wt-specific stuff

        #

        # See https://bugs.edge.launchpad.net/bzr/+bug/553017