blob: 9da1bc8f977183e9753cb5cf4b6b7e93c630a07e [file] [log] [blame]
#! /usr/bin/env python
#
# Copyright 2009 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Test that FakeFilesystem calls work identically to a real filesystem."""
#pylint: disable-all
import os #@UnusedImport
import os.path
import shutil
import sys
import tempfile
import time
import sys
if sys.version_info < (2, 7):
import unittest2 as unittest
else:
import unittest
import fake_filesystem
def Sep(path):
"""Converts slashes in the path to the architecture's path seperator."""
if isinstance(path, str):
return path.replace('/', os.sep)
return path
class TestCase(unittest.TestCase):
is_windows = sys.platform.startswith('win')
is_cygwin = sys.platform == 'cygwin'
_FAKE_FS_BASE = Sep('/fakefs')
class FakeFilesystemVsRealTest(TestCase):
def _Paths(self, path):
"""For a given path, return paths in the real and fake filesystems."""
if not path:
return (None, None)
return (os.path.join(self.real_base, path),
os.path.join(self.fake_base, path))
def _CreateTestFile(self, file_type, path, contents=None):
"""Create a dir, file, or link in both the real fs and the fake."""
path = Sep(path)
self._created_files.append([file_type, path, contents])
real_path, fake_path = self._Paths(path)
if file_type == 'd':
os.mkdir(real_path)
self.fake_os.mkdir(fake_path)
if file_type == 'f':
fh = open(real_path, 'w')
fh.write(contents or '')
fh.close()
fh = self.fake_open(fake_path, 'w')
fh.write(contents or '')
fh.close()
# b for binary file
if file_type == 'b':
fh = open(real_path, 'wb')
fh.write(contents or '')
fh.close()
fh = self.fake_open(fake_path, 'wb')
fh.write(contents or '')
fh.close()
# l for symlink, h for hard link
if file_type in ('l', 'h'):
real_target, fake_target = (contents, contents)
# If it begins with '/', make it relative to the base. You can't go
# creating files in / for the real file system.
if contents.startswith(os.sep):
real_target, fake_target = self._Paths(contents[1:])
if file_type == 'l':
os.symlink(real_target, real_path)
self.fake_os.symlink(fake_target, fake_path)
elif file_type == 'h':
os.link(real_target, real_path)
self.fake_os.link(fake_target, fake_path)
def setUp(self):
# Base paths in the real and test file systems. We keep them different
# so that missing features in the fake don't fall through to the base
# operations and magically succeed.
tsname = 'fakefs.%s' % time.time()
# Fully expand the base_path - required on OS X.
self.real_base = os.path.realpath(
os.path.join(tempfile.gettempdir(), tsname))
os.chdir(tempfile.gettempdir())
if os.path.isdir(self.real_base):
shutil.rmtree(self.real_base)
os.mkdir(self.real_base)
self.fake_base = self._FAKE_FS_BASE
# Make sure we can write to the physical testing temp directory.
self.assertTrue(os.access(self.real_base, os.W_OK))
self.fake_filesystem = fake_filesystem.FakeFilesystem()
self.fake_filesystem.CreateDirectory(self.fake_base)
self.fake_os = fake_filesystem.FakeOsModule(self.fake_filesystem)
self.fake_open = fake_filesystem.FakeFileOpen(self.fake_filesystem)
self._created_files = []
os.chdir(self.real_base)
self.fake_os.chdir(self.fake_base)
def tearDown(self):
# We have to remove all the files from the real FS. Doing the same for the
# fake FS is optional, but doing it is an extra sanity check.
os.chdir(tempfile.gettempdir())
try:
rev_files = self._created_files[:]
rev_files.reverse()
for info in rev_files:
real_path, fake_path = self._Paths(info[1])
if info[0] == 'd':
try:
os.rmdir(real_path)
except OSError as e:
if 'Directory not empty' in e:
self.fail('Real path %s not empty: %s : %s' % (
real_path, e, os.listdir(real_path)))
else:
raise
self.fake_os.rmdir(fake_path)
if info[0] == 'f' or info[0] == 'l':
os.remove(real_path)
self.fake_os.remove(fake_path)
finally:
shutil.rmtree(self.real_base)
def _GetErrno(self, raised_error):
try:
return (raised_error and raised_error.errno) or None
except AttributeError:
return None
def _CompareBehaviors(self, method_name, path, real, fake,
method_returns_path=False):
"""Invoke an os method in both real and fake contexts and compare results.
Invoke a real filesystem method with a path to a real file and invoke a fake
filesystem method with a path to a fake file and compare the results. We
expect some calls to throw Exceptions, so we catch those and compare them.
Args:
method_name: Name of method being tested, for use in error messages.
path: potential path to a file in the real and fake file systems, passing
an empty tuple indicates that no arguments to pass to method.
real: built-in system library or method from the built-in system library
which takes a path as an arg and returns some value.
fake: fake_filsystem object or method from a fake_filesystem class
which takes a path as an arg and returns some value.
method_returns_path: True if the method returns a path, and thus we must
compensate for expected difference between real and fake.
Returns:
A description of the difference in behavior, or None.
"""
# pylint: disable=C6403
def _ErrorClass(e):
return (e and e.__class__.__name__) or 'None'
real_value = None
fake_value = None
real_err = None
fake_err = None
method_call = '%s' % method_name
method_call += '()' if path == () else '(%s)' % path
# Catching Exception below gives a lint warning, but it's what we need.
try:
args = [] if path == () else [path]
real_method = real
if not callable(real):
real_method = getattr(real, method_name)
real_value = str(real_method(*args))
except Exception as e: # pylint: disable-msg=W0703
real_err = e
try:
fake_method = fake
if not callable(fake):
fake_method = getattr(fake, method_name)
args = [] if path == () else [path]
fake_value = str(fake_method(*args))
except Exception as e: # pylint: disable-msg=W0703
fake_err = e
# We only compare on the error class because the acutal error contents
# is almost always different because of the file paths.
if _ErrorClass(real_err) != _ErrorClass(fake_err):
if real_err is None:
return '%s: real version returned %s, fake raised %s' % (
method_call, real_value, _ErrorClass(fake_err))
if fake_err is None:
return '%s: real version raised %s, fake returned %s' % (
method_call, _ErrorClass(real_err), fake_value)
return '%s: real version raised %s, fake raised %s' % (
method_call, _ErrorClass(real_err), _ErrorClass(fake_err))
real_errno = self._GetErrno(real_err)
fake_errno = self._GetErrno(fake_err)
if real_errno != fake_errno:
return '%s(%s): both raised %s, real errno %s, fake errno %s' % (
method_name, path, _ErrorClass(real_err), real_errno, fake_errno)
# If the method is supposed to return a full path AND both values
# begin with the expected full path, then trim it off.
if method_returns_path:
if (real_value and fake_value
and real_value.startswith(self.real_base)
and fake_value.startswith(self.fake_base)):
real_value = real_value[len(self.real_base):]
fake_value = fake_value[len(self.fake_base):]
if real_value != fake_value:
return '%s: real return %s, fake returned %s' % (
method_call, real_value, fake_value)
return None
def assertOsMethodBehaviorMatches(self, method_name, path,
method_returns_path=False):
"""Invoke an os method in both real and fake contexts and compare.
For a given method name (from the os module) and a path, compare the
behavior of the system provided module against the fake_filesytem module.
We expect results and/or Exceptions raised to be identical.
Args:
method_name: Name of method being tested.
path: potential path to a file in the real and fake file systems.
method_returns_path: True if the method returns a path, and thus we must
compensate for expected difference between real and fake.
Returns:
A description of the difference in behavior, or None.
"""
path = Sep(path)
return self._CompareBehaviors(method_name, path, os, self.fake_os,
method_returns_path)
def DiffOpenMethodBehavior(self, method_name, path, mode, data,
method_returns_data=True):
"""Invoke an open method in both real and fkae contexts and compare.
Args:
method_name: Name of method being tested.
path: potential path to a file in the real and fake file systems.
mode: how to open the file.
data: any data to pass to the method.
method_returns_data: True if a method returns some sort of data.
For a given method name (from builtin open) and a path, compare the
behavior of the system provided module against the fake_filesytem module.
We expect results and/or Exceptions raised to be identical.
Returns:
A description of the difference in behavior, or None.
"""
with open(path, mode) as real_fh:
with self.fake_open(path, mode) as fake_fh:
return self._CompareBehaviors(method_name, data, real_fh, fake_fh,
method_returns_data)
def DiffOsPathMethodBehavior(self, method_name, path,
method_returns_path=False):
"""Invoke an os.path method in both real and fake contexts and compare.
For a given method name (from the os.path module) and a path, compare the
behavior of the system provided module against the fake_filesytem module.
We expect results and/or Exceptions raised to be identical.
Args:
method_name: Name of method being tested.
path: potential path to a file in the real and fake file systems.
method_returns_path: True if the method returns a path, and thus we must
compensate for expected difference between real and fake.
Returns:
A description of the difference in behavior, or None.
"""
return self._CompareBehaviors(method_name, path, os.path, self.fake_os.path,
method_returns_path)
def assertOsPathMethodBehaviorMatches(self, method_name, path,
method_returns_path=False):
"""Assert that an os.path behaves the same in both real and fake contexts.
Wraps DiffOsPathMethodBehavior, raising AssertionError if any differences
are reported.
Args:
method_name: Name of method being tested.
path: potential path to a file in the real and fake file systems.
method_returns_path: True if the method returns a path, and thus we must
compensate for expected difference between real and fake.
Raises:
AssertionError if there is any difference in behavior.
"""
path = Sep(path)
diff = self.DiffOsPathMethodBehavior(method_name, path, method_returns_path)
if diff:
self.fail(diff)
def assertAllOsBehaviorsMatch(self, path):
path = Sep(path)
os_method_names = [] if self.is_windows else ['readlink']
os_method_names_no_args = ['getcwd']
if sys.version_info < (3, 0):
os_method_names_no_args.append('getcwdu')
os_path_method_names = ['isabs',
'isdir',
'isfile',
'exists'
]
if not self.is_windows:
os_path_method_names.append('islink')
os_path_method_names.append('lexists')
wrapped_methods = [['access', self._AccessReal, self._AccessFake],
['stat.size', self._StatSizeReal, self._StatSizeFake],
['lstat.size', self._LstatSizeReal, self._LstatSizeFake]
]
differences = []
for method_name in os_method_names:
diff = self.assertOsMethodBehaviorMatches(method_name, path)
if diff:
differences.append(diff)
for method_name in os_method_names_no_args:
diff = self.assertOsMethodBehaviorMatches(method_name, (),
method_returns_path=True)
if diff:
differences.append(diff)
for method_name in os_path_method_names:
diff = self.DiffOsPathMethodBehavior(method_name, path)
if diff:
differences.append(diff)
for m in wrapped_methods:
diff = self._CompareBehaviors(m[0], path, m[1], m[2])
if diff:
differences.append(diff)
if differences:
self.fail('Behaviors do not match for %s:\n %s' %
(path, '\n '.join(differences)))
def assertFileHandleBehaviorsMatch(self, path, mode, data):
path = Sep(path)
write_method_names = ['write', 'writelines']
read_method_names = ['read', 'readlines']
other_method_names = ['truncate', 'flush', 'close']
differences = []
for method_name in write_method_names:
diff = self.DiffOpenMethodBehavior(method_name, path, mode, data)
if diff:
differences.append(diff)
for method_name in read_method_names + other_method_names:
diff = self.DiffOpenMethodBehavior(method_name, path, mode, ())
if diff:
differences.append(diff)
if differences:
self.fail('Behaviors do not match for %s:\n %s' %
(path, '\n '.join(differences)))
# Helpers for checks which are not straight method calls.
def _AccessReal(self, path):
return os.access(path, os.R_OK)
def _AccessFake(self, path):
return self.fake_os.access(path, os.R_OK)
def _StatSizeReal(self, path):
real_path, unused_fake_path = self._Paths(path)
# fake_filesystem.py does not implement stat().st_size for directories
if os.path.isdir(real_path):
return None
return os.stat(real_path).st_size
def _StatSizeFake(self, path):
unused_real_path, fake_path = self._Paths(path)
# fake_filesystem.py does not implement stat().st_size for directories
if self.fake_os.path.isdir(fake_path):
return None
return self.fake_os.stat(fake_path).st_size
def _LstatSizeReal(self, path):
real_path, unused_fake_path = self._Paths(path)
if os.path.isdir(real_path):
return None
size = os.lstat(real_path).st_size
# Account for the difference in the lengths of the absolute paths.
if os.path.islink(real_path):
if os.readlink(real_path).startswith(os.sep):
size -= len(self.real_base)
return size
def _LstatSizeFake(self, path):
unused_real_path, fake_path = self._Paths(path)
#size = 0
if self.fake_os.path.isdir(fake_path):
return None
size = self.fake_os.lstat(fake_path).st_size
# Account for the difference in the lengths of the absolute paths.
if self.fake_os.path.islink(fake_path):
if self.fake_os.readlink(fake_path).startswith(os.sep):
size -= len(self.fake_base)
return size
def testIsabs(self):
# We do not have to create any files for isabs.
self.assertOsPathMethodBehaviorMatches('isabs', None)
self.assertOsPathMethodBehaviorMatches('isabs', '')
self.assertOsPathMethodBehaviorMatches('isabs', '/')
self.assertOsPathMethodBehaviorMatches('isabs', '/a')
self.assertOsPathMethodBehaviorMatches('isabs', 'a')
def testNonePath(self):
self.assertAllOsBehaviorsMatch(None)
def testEmptyPath(self):
self.assertAllOsBehaviorsMatch('')
def testRootPath(self):
self.assertAllOsBehaviorsMatch('/')
def testNonExistantFile(self):
self.assertAllOsBehaviorsMatch('foo')
def testEmptyFile(self):
self._CreateTestFile('f', 'aFile')
self.assertAllOsBehaviorsMatch('aFile')
def testFileWithContents(self):
self._CreateTestFile('f', 'aFile', 'some contents')
self.assertAllOsBehaviorsMatch('aFile')
def testFileWithBinaryContents(self):
self._CreateTestFile('b', 'aFile', b'some contents')
self.assertAllOsBehaviorsMatch('aFile')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testSymLinkToEmptyFile(self):
self._CreateTestFile('f', 'aFile')
self._CreateTestFile('l', 'link_to_empty', 'aFile')
self.assertAllOsBehaviorsMatch('link_to_empty')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def TBD_testHardLinkToEmptyFile(self):
self._CreateTestFile('f', 'aFile')
self._CreateTestFile('h', 'link_to_empty', 'aFile')
self.assertAllOsBehaviorsMatch('link_to_empty')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testSymLinkToRealFile(self):
self._CreateTestFile('f', 'aFile', 'some contents')
self._CreateTestFile('l', 'link_to_file', 'aFile')
self.assertAllOsBehaviorsMatch('link_to_file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def TBD_testHardLinkToRealFile(self):
self._CreateTestFile('f', 'aFile', 'some contents')
self._CreateTestFile('h', 'link_to_file', 'aFile')
self.assertAllOsBehaviorsMatch('link_to_file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testBrokenSymLink(self):
self._CreateTestFile('l', 'broken_link', 'broken')
self._CreateTestFile('l', 'loop', '/a/loop')
self.assertAllOsBehaviorsMatch('broken_link')
def testFileInAFolder(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('f', 'a/b/file', 'contents')
self.assertAllOsBehaviorsMatch('a/b/file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testAbsoluteSymLinkToFolder(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('f', 'a/b/file', 'contents')
self._CreateTestFile('l', 'a/link', '/a/b')
self.assertAllOsBehaviorsMatch('a/link/file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testLinkToFolderAfterChdir(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('f', 'a/b/file', 'contents')
self._CreateTestFile('l', 'a/link', '/a/b')
real_dir, fake_dir = self._Paths('a/b')
os.chdir(real_dir)
self.fake_os.chdir(fake_dir)
self.assertAllOsBehaviorsMatch('file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testRelativeSymLinkToFolder(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('f', 'a/b/file', 'contents')
self._CreateTestFile('l', 'a/link', 'b')
self.assertAllOsBehaviorsMatch('a/link/file')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testSymLinkToParent(self):
# Soft links on HFS+ / OS X behave differently.
if os.uname()[0] != 'Darwin':
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('l', 'a/b/c', '..')
self.assertAllOsBehaviorsMatch('a/b/c')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testPathThroughSymLinkToParent(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('f', 'a/target', 'contents')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('l', 'a/b/c', '..')
self.assertAllOsBehaviorsMatch('a/b/c/target')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testSymLinkToSiblingDirectory(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self._CreateTestFile('l', 'a/b/c', '../sibling_of_b')
self.assertAllOsBehaviorsMatch('a/b/c/target')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testSymLinkToSiblingDirectoryNonExistantFile(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self._CreateTestFile('l', 'a/b/c', '../sibling_of_b')
self.assertAllOsBehaviorsMatch('a/b/c/file_does_not_exist')
@unittest.skipIf(TestCase.is_windows, 'no symlink in Windows')
def testBrokenSymLinkToSiblingDirectory(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self._CreateTestFile('l', 'a/b/c', '../broken_sibling_of_b')
self.assertAllOsBehaviorsMatch('a/b/c/target')
def testRelativePath(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self.assertAllOsBehaviorsMatch('a/b/../sibling_of_b/target')
def testBrokenRelativePath(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self.assertAllOsBehaviorsMatch('a/b/../broken/target')
def testBadRelativePath(self):
self._CreateTestFile('d', 'a')
self._CreateTestFile('f', 'a/target', 'contents')
self._CreateTestFile('d', 'a/b')
self._CreateTestFile('d', 'a/sibling_of_b')
self._CreateTestFile('f', 'a/sibling_of_b/target', 'contents')
self.assertAllOsBehaviorsMatch('a/b/../broken/../target')
def testGetmtimeNonexistantPath(self):
self.assertOsPathMethodBehaviorMatches('getmtime', 'no/such/path')
def testBuiltinOpenModes(self):
self._CreateTestFile('f', 'read', 'some contents')
self._CreateTestFile('f', 'write', 'some contents')
self._CreateTestFile('f', 'append', 'some contents')
self.assertFileHandleBehaviorsMatch('read', 'r', 'other contents')
self.assertFileHandleBehaviorsMatch('write', 'w', 'other contents')
self.assertFileHandleBehaviorsMatch('append', 'a', 'other contents')
self._CreateTestFile('f', 'readplus', 'some contents')
self._CreateTestFile('f', 'writeplus', 'some contents')
self.assertFileHandleBehaviorsMatch('readplus', 'r+', 'other contents')
self.assertFileHandleBehaviorsMatch('writeplus', 'w+', 'other contents')
self._CreateTestFile('b', 'binaryread', b'some contents')
self._CreateTestFile('b', 'binarywrite', b'some contents')
self._CreateTestFile('b', 'binaryappend', b'some contents')
self.assertFileHandleBehaviorsMatch('binaryread', 'rb', b'other contents')
self.assertFileHandleBehaviorsMatch('binarywrite', 'wb', b'other contents')
self.assertFileHandleBehaviorsMatch('binaryappend', 'ab', b'other contents')
self.assertFileHandleBehaviorsMatch('read', 'rb', 'other contents')
self.assertFileHandleBehaviorsMatch('write', 'wb', 'other contents')
self.assertFileHandleBehaviorsMatch('append', 'ab', 'other contents')
def main(unused_argv):
unittest.main()
if __name__ == '__main__':
unittest.main()