blob: 36abab42d6a8f58c13be26ef220adffd6f507936 [file] [log] [blame]
# Copyright (c) 2011 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Simplify unit tests based on pymox."""
import os
import random
import shutil
import string
import StringIO
import subprocess
import sys
from third_party.pymox import mox
class IsOneOf(mox.Comparator):
def __init__(self, keys):
self._keys = keys
def equals(self, rhs):
return rhs in self._keys
def __repr__(self):
return '<sequence or map containing \'%s\'>' % str(self._keys)
class TestCaseUtils(object):
"""Base class with some additional functionalities. People will usually want
to use SuperMoxTestBase instead."""
# Backup the separator in case it gets mocked
_OS_SEP = os.sep
_RANDOM_CHOICE = random.choice
_RANDOM_RANDINT = random.randint
_STRING_LETTERS = string.letters
## Some utilities for generating arbitrary arguments.
def String(self, max_length):
return ''.join([self._RANDOM_CHOICE(self._STRING_LETTERS)
for _ in xrange(self._RANDOM_RANDINT(1, max_length))])
def Strings(self, max_arg_count, max_arg_length):
return [self.String(max_arg_length) for _ in xrange(max_arg_count)]
def Args(self, max_arg_count=8, max_arg_length=16):
return self.Strings(max_arg_count,
self._RANDOM_RANDINT(1, max_arg_length))
def _DirElts(self, max_elt_count=4, max_elt_length=8):
return self._OS_SEP.join(self.Strings(max_elt_count, max_elt_length))
def Dir(self, max_elt_count=4, max_elt_length=8):
return (self._RANDOM_CHOICE((self._OS_SEP, '')) +
self._DirElts(max_elt_count, max_elt_length))
def RootDir(self, max_elt_count=4, max_elt_length=8):
return self._OS_SEP + self._DirElts(max_elt_count, max_elt_length)
def compareMembers(self, obj, members):
"""If you add a member, be sure to add the relevant test!"""
# Skip over members starting with '_' since they are usually not meant to
# be for public use.
actual_members = [x for x in sorted(dir(obj))
if not x.startswith('_')]
expected_members = sorted(members)
if actual_members != expected_members:
diff = ([i for i in actual_members if i not in expected_members] +
[i for i in expected_members if i not in actual_members])
print >> sys.stderr, diff
# pylint: disable=E1101
self.assertEqual(actual_members, expected_members)
def setUp(self):
self.root_dir = self.Dir()
self.args = self.Args()
self.relpath = self.String(200)
def tearDown(self):
class StdoutCheck(object):
def setUp(self):
# Override the mock with a StringIO, it's much less painful to test.
self._old_stdout = sys.stdout
stdout = StringIO.StringIO()
stdout.flush = lambda: None
sys.stdout = stdout
def tearDown(self):
# If sys.stdout was used, self.checkstdout() must be called.
# pylint: disable=E1101
if not sys.stdout.closed:
self.assertEquals('', sys.stdout.getvalue())
except AttributeError:
sys.stdout = self._old_stdout
def checkstdout(self, expected):
value = sys.stdout.getvalue()
# pylint: disable=E1101
self.assertEquals(expected, value)
class SuperMoxTestBase(TestCaseUtils, StdoutCheck, mox.MoxTestBase):
def setUp(self):
"""Patch a few functions with know side-effects."""
os_to_mock = ('chdir', 'chown', 'close', 'closerange', 'dup', 'dup2',
'fchdir', 'fchmod', 'fchown', 'fdopen', 'getcwd', 'lseek',
'makedirs', 'mkdir', 'open', 'popen', 'popen2', 'popen3', 'popen4',
'read', 'remove', 'removedirs', 'rename', 'renames', 'rmdir', 'symlink',
'system', 'tmpfile', 'walk', 'write')
self.MockList(os, os_to_mock)
os_path_to_mock = ('abspath', 'exists', 'getsize', 'isdir', 'isfile',
'islink', 'ismount', 'lexists', 'realpath', 'samefile', 'walk')
self.MockList(os.path, os_path_to_mock)
self.MockList(shutil, ('rmtree'))
self.MockList(subprocess, ('call', 'Popen'))
# Don't mock stderr since it confuses unittests.
self.MockList(sys, ('stdin'))
def tearDown(self):
def MockList(self, parent, items_to_mock):
for item in items_to_mock:
# Skip over items not present because of OS-specific implementation,
# implemented only in later python version, etc.
if hasattr(parent, item):
self.mox.StubOutWithMock(parent, item)
except TypeError, e:
raise TypeError(
'Couldn\'t mock %s in %s: %s' % (item, parent.__name__, e))
def UnMock(self, obj, name):
"""Restore an object inside a test."""
for (parent, old_child, child_name) in self.mox.stubs.cache:
if parent == obj and child_name == name:
setattr(parent, child_name, old_child)