diff options
Diffstat (limited to 'tests/support_tests.py')
| -rw-r--r-- | tests/support_tests.py | 1725 |
1 files changed, 0 insertions, 1725 deletions
diff --git a/tests/support_tests.py b/tests/support_tests.py deleted file mode 100644 index 2c56e12d..00000000 --- a/tests/support_tests.py +++ /dev/null @@ -1,1725 +0,0 @@ -"""Supporting definitions for the Python regression tests.""" - -if __name__ != 'test.support': - raise ImportError('support must be imported from the test package') - -import contextlib -import errno -import functools -import gc -import socket -import sys -import os -import platform -import shutil -import warnings -import unittest -import importlib -import collections.abc -import re -import subprocess -import imp -import time -import sysconfig -import fnmatch -import logging.handlers -import struct - -try: - import _thread, threading -except ImportError: - _thread = None - threading = None -try: - import multiprocessing.process -except ImportError: - multiprocessing = None - -try: - import faulthandler -except ImportError: - faulthandler = None - -try: - import zlib -except ImportError: - zlib = None - -__all__ = [ - "Error", "TestFailed", "ResourceDenied", "import_module", - "verbose", "use_resources", "max_memuse", "record_original_stdout", - "get_original_stdout", "unload", "unlink", "rmtree", "forget", - "is_resource_enabled", "requires", "requires_freebsd_version", - "requires_linux_version", "requires_mac_ver", "find_unused_port", "bind_port", - "IPV6_ENABLED", "is_jython", "TESTFN", "HOST", "SAVEDCWD", "temp_cwd", - "findfile", "create_empty_file", "sortdict", "check_syntax_error", "open_urlresource", - "check_warnings", "CleanImport", "EnvironmentVarGuard", "TransientResource", - "captured_stdout", "captured_stdin", "captured_stderr", "time_out", - "socket_peer_reset", "ioerror_peer_reset", "run_with_locale", 'temp_umask', - "transient_internet", "set_memlimit", "bigmemtest", "bigaddrspacetest", - "BasicTestRunner", "run_unittest", "run_doctest", "threading_setup", - "threading_cleanup", "reap_children", "cpython_only", "check_impl_detail", - "get_attribute", "swap_item", "swap_attr", "requires_IEEE_754", - "TestHandler", "Matcher", "can_symlink", "skip_unless_symlink", - "import_fresh_module", "requires_zlib", "PIPE_MAX_SIZE", "failfast", - "anticipate_failure" - ] - -class Error(Exception): - """Base class for regression test exceptions.""" - -class TestFailed(Error): - """Test failed.""" - -class ResourceDenied(unittest.SkipTest): - """Test skipped because it requested a disallowed resource. - - This is raised when a test calls requires() for a resource that - has not be enabled. It is used to distinguish between expected - and unexpected skips. - """ - -@contextlib.contextmanager -def _ignore_deprecated_imports(ignore=True): - """Context manager to suppress package and module deprecation - warnings when importing them. - - If ignore is False, this context manager has no effect.""" - if ignore: - with warnings.catch_warnings(): - warnings.filterwarnings("ignore", ".+ (module|package)", - DeprecationWarning) - yield - else: - yield - - -def import_module(name, deprecated=False): - """Import and return the module to be tested, raising SkipTest if - it is not available. - - If deprecated is True, any module or package deprecation messages - will be suppressed.""" - with _ignore_deprecated_imports(deprecated): - try: - return importlib.import_module(name) - except ImportError as msg: - raise unittest.SkipTest(str(msg)) - - -def _save_and_remove_module(name, orig_modules): - """Helper function to save and remove a module from sys.modules - - Raise ImportError if the module can't be imported.""" - # try to import the module and raise an error if it can't be imported - if name not in sys.modules: - __import__(name) - del sys.modules[name] - for modname in list(sys.modules): - if modname == name or modname.startswith(name + '.'): - orig_modules[modname] = sys.modules[modname] - del sys.modules[modname] - -def _save_and_block_module(name, orig_modules): - """Helper function to save and block a module in sys.modules - - Return True if the module was in sys.modules, False otherwise.""" - saved = True - try: - orig_modules[name] = sys.modules[name] - except KeyError: - saved = False - sys.modules[name] = None - return saved - - -def anticipate_failure(condition): - """Decorator to mark a test that is known to be broken in some cases - - Any use of this decorator should have a comment identifying the - associated tracker issue. - """ - if condition: - return unittest.expectedFailure - return lambda f: f - - -def import_fresh_module(name, fresh=(), blocked=(), deprecated=False): - """Imports and returns a module, deliberately bypassing the sys.modules cache - and importing a fresh copy of the module. Once the import is complete, - the sys.modules cache is restored to its original state. - - Modules named in fresh are also imported anew if needed by the import. - If one of these modules can't be imported, None is returned. - - Importing of modules named in blocked is prevented while the fresh import - takes place. - - If deprecated is True, any module or package deprecation messages - will be suppressed.""" - # NOTE: test_heapq, test_json and test_warnings include extra sanity checks - # to make sure that this utility function is working as expected - with _ignore_deprecated_imports(deprecated): - # Keep track of modules saved for later restoration as well - # as those which just need a blocking entry removed - orig_modules = {} - names_to_remove = [] - _save_and_remove_module(name, orig_modules) - try: - for fresh_name in fresh: - _save_and_remove_module(fresh_name, orig_modules) - for blocked_name in blocked: - if not _save_and_block_module(blocked_name, orig_modules): - names_to_remove.append(blocked_name) - fresh_module = importlib.import_module(name) - except ImportError: - fresh_module = None - finally: - for orig_name, module in orig_modules.items(): - sys.modules[orig_name] = module - for name_to_remove in names_to_remove: - del sys.modules[name_to_remove] - return fresh_module - - -def get_attribute(obj, name): - """Get an attribute, raising SkipTest if AttributeError is raised.""" - try: - attribute = getattr(obj, name) - except AttributeError: - raise unittest.SkipTest("object %r has no attribute %r" % (obj, name)) - else: - return attribute - -verbose = 1 # Flag set to 0 by regrtest.py -use_resources = None # Flag set to [] by regrtest.py -max_memuse = 0 # Disable bigmem tests (they will still be run with - # small sizes, to make sure they work.) -real_max_memuse = 0 -failfast = False -match_tests = None - -# _original_stdout is meant to hold stdout at the time regrtest began. -# This may be "the real" stdout, or IDLE's emulation of stdout, or whatever. -# The point is to have some flavor of stdout the user can actually see. -_original_stdout = None -def record_original_stdout(stdout): - global _original_stdout - _original_stdout = stdout - -def get_original_stdout(): - return _original_stdout or sys.stdout - -def unload(name): - try: - del sys.modules[name] - except KeyError: - pass - -def unlink(filename): - try: - os.unlink(filename) - except OSError as error: - # The filename need not exist. - if error.errno not in (errno.ENOENT, errno.ENOTDIR): - raise - -def rmtree(path): - try: - shutil.rmtree(path) - except OSError as error: - if error.errno != errno.ENOENT: - raise - -def make_legacy_pyc(source): - """Move a PEP 3147 pyc/pyo file to its legacy pyc/pyo location. - - The choice of .pyc or .pyo extension is done based on the __debug__ flag - value. - - :param source: The file system path to the source file. The source file - does not need to exist, however the PEP 3147 pyc file must exist. - :return: The file system path to the legacy pyc file. - """ - pyc_file = imp.cache_from_source(source) - up_one = os.path.dirname(os.path.abspath(source)) - legacy_pyc = os.path.join(up_one, source + ('c' if __debug__ else 'o')) - os.rename(pyc_file, legacy_pyc) - return legacy_pyc - -def forget(modname): - """'Forget' a module was ever imported. - - This removes the module from sys.modules and deletes any PEP 3147 or - legacy .pyc and .pyo files. - """ - unload(modname) - for dirname in sys.path: - source = os.path.join(dirname, modname + '.py') - # It doesn't matter if they exist or not, unlink all possible - # combinations of PEP 3147 and legacy pyc and pyo files. - unlink(source + 'c') - unlink(source + 'o') - unlink(imp.cache_from_source(source, debug_override=True)) - unlink(imp.cache_from_source(source, debug_override=False)) - -# On some platforms, should not run gui test even if it is allowed -# in `use_resources'. -if sys.platform.startswith('win'): - import ctypes - import ctypes.wintypes - def _is_gui_available(): - UOI_FLAGS = 1 - WSF_VISIBLE = 0x0001 - class USEROBJECTFLAGS(ctypes.Structure): - _fields_ = [("fInherit", ctypes.wintypes.BOOL), - ("fReserved", ctypes.wintypes.BOOL), - ("dwFlags", ctypes.wintypes.DWORD)] - dll = ctypes.windll.user32 - h = dll.GetProcessWindowStation() - if not h: - raise ctypes.WinError() - uof = USEROBJECTFLAGS() - needed = ctypes.wintypes.DWORD() - res = dll.GetUserObjectInformationW(h, - UOI_FLAGS, - ctypes.byref(uof), - ctypes.sizeof(uof), - ctypes.byref(needed)) - if not res: - raise ctypes.WinError() - return bool(uof.dwFlags & WSF_VISIBLE) -else: - def _is_gui_available(): - return True - -def is_resource_enabled(resource): - """Test whether a resource is enabled. Known resources are set by - regrtest.py.""" - return use_resources is not None and resource in use_resources - -def requires(resource, msg=None): - """Raise ResourceDenied if the specified resource is not available. - - If the caller's module is __main__ then automatically return True. The - possibility of False being returned occurs when regrtest.py is - executing. - """ - if resource == 'gui' and not _is_gui_available(): - raise unittest.SkipTest("Cannot use the 'gui' resource") - # see if the caller's module is __main__ - if so, treat as if - # the resource was set - if sys._getframe(1).f_globals.get("__name__") == "__main__": - return - if not is_resource_enabled(resource): - if msg is None: - msg = "Use of the %r resource not enabled" % resource - raise ResourceDenied(msg) - -def _requires_unix_version(sysname, min_version): - """Decorator raising SkipTest if the OS is `sysname` and the version is less - than `min_version`. - - For example, @_requires_unix_version('FreeBSD', (7, 2)) raises SkipTest if - the FreeBSD version is less than 7.2. - """ - def decorator(func): - @functools.wraps(func) - def wrapper(*args, **kw): - if platform.system() == sysname: - version_txt = platform.release().split('-', 1)[0] - try: - version = tuple(map(int, version_txt.split('.'))) - except ValueError: - pass - else: - if version < min_version: - min_version_txt = '.'.join(map(str, min_version)) - raise unittest.SkipTest( - "%s version %s or higher required, not %s" - % (sysname, min_version_txt, version_txt)) - return wrapper - return decorator - -def requires_freebsd_version(*min_version): - """Decorator raising SkipTest if the OS is FreeBSD and the FreeBSD version is - less than `min_version`. - - For example, @requires_freebsd_version(7, 2) raises SkipTest if the FreeBSD - version is less than 7.2. - """ - return _requires_unix_version('FreeBSD', min_version) - -def requires_linux_version(*min_version): - """Decorator raising SkipTest if the OS is Linux and the Linux version is - less than `min_version`. - - For example, @requires_linux_version(2, 6, 32) raises SkipTest if the Linux - version is less than 2.6.32. - """ - return _requires_unix_version('Linux', min_version) - -def requires_mac_ver(*min_version): - """Decorator raising SkipTest if the OS is Mac OS X and the OS X - version if less than min_version. - - For example, @requires_mac_ver(10, 5) raises SkipTest if the OS X version - is lesser than 10.5. - """ - def decorator(func): - @functools.wraps(func) - def wrapper(*args, **kw): - if sys.platform == 'darwin': - version_txt = platform.mac_ver()[0] - try: - version = tuple(map(int, version_txt.split('.'))) - except ValueError: - pass - else: - if version < min_version: - min_version_txt = '.'.join(map(str, min_version)) - raise unittest.SkipTest( - "Mac OS X %s or higher required, not %s" - % (min_version_txt, version_txt)) - return func(*args, **kw) - wrapper.min_version = min_version - return wrapper - return decorator - - -HOST = 'localhost' - -def find_unused_port(family=socket.AF_INET, socktype=socket.SOCK_STREAM): - """Returns an unused port that should be suitable for binding. This is - achieved by creating a temporary socket with the same family and type as - the 'sock' parameter (default is AF_INET, SOCK_STREAM), and binding it to - the specified host address (defaults to 0.0.0.0) with the port set to 0, - eliciting an unused ephemeral port from the OS. The temporary socket is - then closed and deleted, and the ephemeral port is returned. - - Either this method or bind_port() should be used for any tests where a - server socket needs to be bound to a particular port for the duration of - the test. Which one to use depends on whether the calling code is creating - a python socket, or if an unused port needs to be provided in a constructor - or passed to an external program (i.e. the -accept argument to openssl's - s_server mode). Always prefer bind_port() over find_unused_port() where - possible. Hard coded ports should *NEVER* be used. As soon as a server - socket is bound to a hard coded port, the ability to run multiple instances - of the test simultaneously on the same host is compromised, which makes the - test a ticking time bomb in a buildbot environment. On Unix buildbots, this - may simply manifest as a failed test, which can be recovered from without - intervention in most cases, but on Windows, the entire python process can - completely and utterly wedge, requiring someone to log in to the buildbot - and manually kill the affected process. - - (This is easy to reproduce on Windows, unfortunately, and can be traced to - the SO_REUSEADDR socket option having different semantics on Windows versus - Unix/Linux. On Unix, you can't have two AF_INET SOCK_STREAM sockets bind, - listen and then accept connections on identical host/ports. An EADDRINUSE - socket.error will be raised at some point (depending on the platform and - the order bind and listen were called on each socket). - - However, on Windows, if SO_REUSEADDR is set on the sockets, no EADDRINUSE - will ever be raised when attempting to bind two identical host/ports. When - accept() is called on each socket, the second caller's process will steal - the port from the first caller, leaving them both in an awkwardly wedged - state where they'll no longer respond to any signals or graceful kills, and - must be forcibly killed via OpenProcess()/TerminateProcess(). - - The solution on Windows is to use the SO_EXCLUSIVEADDRUSE socket option - instead of SO_REUSEADDR, which effectively affords the same semantics as - SO_REUSEADDR on Unix. Given the propensity of Unix developers in the Open - Source world compared to Windows ones, this is a common mistake. A quick - look over OpenSSL's 0.9.8g source shows that they use SO_REUSEADDR when - openssl.exe is called with the 's_server' option, for example. See - http://bugs.python.org/issue2550 for more info. The following site also - has a very thorough description about the implications of both REUSEADDR - and EXCLUSIVEADDRUSE on Windows: - http://msdn2.microsoft.com/en-us/library/ms740621(VS.85).aspx) - - XXX: although this approach is a vast improvement on previous attempts to - elicit unused ports, it rests heavily on the assumption that the ephemeral - port returned to us by the OS won't immediately be dished back out to some - other process when we close and delete our temporary socket but before our - calling code has a chance to bind the returned port. We can deal with this - issue if/when we come across it. - """ - - tempsock = socket.socket(family, socktype) - port = bind_port(tempsock) - tempsock.close() - del tempsock - return port - -def bind_port(sock, host=HOST): - """Bind the socket to a free port and return the port number. Relies on - ephemeral ports in order to ensure we are using an unbound port. This is - important as many tests may be running simultaneously, especially in a - buildbot environment. This method raises an exception if the sock.family - is AF_INET and sock.type is SOCK_STREAM, *and* the socket has SO_REUSEADDR - or SO_REUSEPORT set on it. Tests should *never* set these socket options - for TCP/IP sockets. The only case for setting these options is testing - multicasting via multiple UDP sockets. - - Additionally, if the SO_EXCLUSIVEADDRUSE socket option is available (i.e. - on Windows), it will be set on the socket. This will prevent anyone else - from bind()'ing to our host/port for the duration of the test. - """ - - if sock.family == socket.AF_INET and sock.type == socket.SOCK_STREAM: - if hasattr(socket, 'SO_REUSEADDR'): - if sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR) == 1: - raise TestFailed("tests should never set the SO_REUSEADDR " \ - "socket option on TCP/IP sockets!") - if hasattr(socket, 'SO_REUSEPORT'): - if sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT) == 1: - raise TestFailed("tests should never set the SO_REUSEPORT " \ - "socket option on TCP/IP sockets!") - if hasattr(socket, 'SO_EXCLUSIVEADDRUSE'): - sock.setsockopt(socket.SOL_SOCKET, socket.SO_EXCLUSIVEADDRUSE, 1) - - sock.bind((host, 0)) - port = sock.getsockname()[1] - return port - -def _is_ipv6_enabled(): - """Check whether IPv6 is enabled on this host.""" - if socket.has_ipv6: - try: - sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM) - sock.bind(('::1', 0)) - except (socket.error, socket.gaierror): - pass - else: - sock.close() - return True - return False - -IPV6_ENABLED = _is_ipv6_enabled() - - -# A constant likely larger than the underlying OS pipe buffer size. -# Windows limit seems to be around 512B, and most Unix kernels have a 64K pipe -# buffer size: take 1M to be sure. -PIPE_MAX_SIZE = 1024 * 1024 - - -# decorator for skipping tests on non-IEEE 754 platforms -requires_IEEE_754 = unittest.skipUnless( - float.__getformat__("double").startswith("IEEE"), - "test requires IEEE 754 doubles") - -requires_zlib = unittest.skipUnless(zlib, 'requires zlib') - -is_jython = sys.platform.startswith('java') - -# Filename used for testing -if os.name == 'java': - # Jython disallows @ in module names - TESTFN = '$test' -else: - TESTFN = '@test' - -# Disambiguate TESTFN for parallel testing, while letting it remain a valid -# module name. -TESTFN = "{}_{}_tmp".format(TESTFN, os.getpid()) - - -# TESTFN_UNICODE is a non-ascii filename -TESTFN_UNICODE = TESTFN + "-\xe0\xf2\u0258\u0141\u011f" -if sys.platform == 'darwin': - # In Mac OS X's VFS API file names are, by definition, canonically - # decomposed Unicode, encoded using UTF-8. See QA1173: - # http://developer.apple.com/mac/library/qa/qa2001/qa1173.html - import unicodedata - TESTFN_UNICODE = unicodedata.normalize('NFD', TESTFN_UNICODE) -TESTFN_ENCODING = sys.getfilesystemencoding() - -# TESTFN_UNENCODABLE is a filename (str type) that should *not* be able to be -# encoded by the filesystem encoding (in strict mode). It can be None if we -# cannot generate such filename. -TESTFN_UNENCODABLE = None -if os.name in ('nt', 'ce'): - # skip win32s (0) or Windows 9x/ME (1) - if sys.getwindowsversion().platform >= 2: - # Different kinds of characters from various languages to minimize the - # probability that the whole name is encodable to MBCS (issue #9819) - TESTFN_UNENCODABLE = TESTFN + "-\u5171\u0141\u2661\u0363\uDC80" - try: - TESTFN_UNENCODABLE.encode(TESTFN_ENCODING) - except UnicodeEncodeError: - pass - else: - print('WARNING: The filename %r CAN be encoded by the filesystem encoding (%s). ' - 'Unicode filename tests may not be effective' - % (TESTFN_UNENCODABLE, TESTFN_ENCODING)) - TESTFN_UNENCODABLE = None -# Mac OS X denies unencodable filenames (invalid utf-8) -elif sys.platform != 'darwin': - try: - # ascii and utf-8 cannot encode the byte 0xff - b'\xff'.decode(TESTFN_ENCODING) - except UnicodeDecodeError: - # 0xff will be encoded using the surrogate character u+DCFF - TESTFN_UNENCODABLE = TESTFN \ - + b'-\xff'.decode(TESTFN_ENCODING, 'surrogateescape') - else: - # File system encoding (eg. ISO-8859-* encodings) can encode - # the byte 0xff. Skip some unicode filename tests. - pass - -# Save the initial cwd -SAVEDCWD = os.getcwd() - -@contextlib.contextmanager -def temp_cwd(name='tempcwd', quiet=False, path=None): - """ - Context manager that temporarily changes the CWD. - - An existing path may be provided as *path*, in which case this - function makes no changes to the file system. - - Otherwise, the new CWD is created in the current directory and it's - named *name*. If *quiet* is False (default) and it's not possible to - create or change the CWD, an error is raised. If it's True, only a - warning is raised and the original CWD is used. - """ - saved_dir = os.getcwd() - is_temporary = False - if path is None: - path = name - try: - os.mkdir(name) - is_temporary = True - except OSError: - if not quiet: - raise - warnings.warn('tests may fail, unable to create temp CWD ' + name, - RuntimeWarning, stacklevel=3) - try: - os.chdir(path) - except OSError: - if not quiet: - raise - warnings.warn('tests may fail, unable to change the CWD to ' + name, - RuntimeWarning, stacklevel=3) - try: - yield os.getcwd() - finally: - os.chdir(saved_dir) - if is_temporary: - rmtree(name) - - -if hasattr(os, "umask"): - @contextlib.contextmanager - def temp_umask(umask): - """Context manager that temporarily sets the process umask.""" - oldmask = os.umask(umask) - try: - yield - finally: - os.umask(oldmask) - - -def findfile(file, here=__file__, subdir=None): - """Try to find a file on sys.path and the working directory. If it is not - found the argument passed to the function is returned (this does not - necessarily signal failure; could still be the legitimate path).""" - if os.path.isabs(file): - return file - if subdir is not None: - file = os.path.join(subdir, file) - path = sys.path - path = [os.path.dirname(here)] + path - for dn in path: - fn = os.path.join(dn, file) - if os.path.exists(fn): return fn - return file - -def create_empty_file(filename): - """Create an empty file. If the file already exists, truncate it.""" - fd = os.open(filename, os.O_WRONLY | os.O_CREAT | os.O_TRUNC) - os.close(fd) - -def sortdict(dict): - "Like repr(dict), but in sorted order." - items = sorted(dict.items()) - reprpairs = ["%r: %r" % pair for pair in items] - withcommas = ", ".join(reprpairs) - return "{%s}" % withcommas - -def make_bad_fd(): - """ - Create an invalid file descriptor by opening and closing a file and return - its fd. - """ - file = open(TESTFN, "wb") - try: - return file.fileno() - finally: - file.close() - unlink(TESTFN) - -def check_syntax_error(testcase, statement): - testcase.assertRaises(SyntaxError, compile, statement, - '<test string>', 'exec') - -def open_urlresource(url, *args, **kw): - import urllib.request, urllib.parse - - check = kw.pop('check', None) - - filename = urllib.parse.urlparse(url)[2].split('/')[-1] # '/': it's URL! - - fn = os.path.join(os.path.dirname(__file__), "data", filename) - - def check_valid_file(fn): - f = open(fn, *args, **kw) - if check is None: - return f - elif check(f): - f.seek(0) - return f - f.close() - - if os.path.exists(fn): - f = check_valid_file(fn) - if f is not None: - return f - unlink(fn) - - # Verify the requirement before downloading the file - requires('urlfetch') - - print('\tfetching %s ...' % url, file=get_original_stdout()) - f = urllib.request.urlopen(url, timeout=15) - try: - with open(fn, "wb") as out: - s = f.read() - while s: - out.write(s) - s = f.read() - finally: - f.close() - - f = check_valid_file(fn) - if f is not None: - return f - raise TestFailed('invalid resource %r' % fn) - - -class WarningsRecorder(object): - """Convenience wrapper for the warnings list returned on - entry to the warnings.catch_warnings() context manager. - """ - def __init__(self, warnings_list): - self._warnings = warnings_list - self._last = 0 - - def __getattr__(self, attr): - if len(self._warnings) > self._last: - return getattr(self._warnings[-1], attr) - elif attr in warnings.WarningMessage._WARNING_DETAILS: - return None - raise AttributeError("%r has no attribute %r" % (self, attr)) - - @property - def warnings(self): - return self._warnings[self._last:] - - def reset(self): - self._last = len(self._warnings) - - -def _filterwarnings(filters, quiet=False): - """Catch the warnings, then check if all the expected - warnings have been raised and re-raise unexpected warnings. - If 'quiet' is True, only re-raise the unexpected warnings. - """ - # Clear the warning registry of the calling module - # in order to re-raise the warnings. - frame = sys._getframe(2) - registry = frame.f_globals.get('__warningregistry__') - if registry: - registry.clear() - with warnings.catch_warnings(record=True) as w: - # Set filter "always" to record all warnings. Because - # test_warnings swap the module, we need to look up in - # the sys.modules dictionary. - sys.modules['warnings'].simplefilter("always") - yield WarningsRecorder(w) - # Filter the recorded warnings - reraise = list(w) - missing = [] - for msg, cat in filters: - seen = False - for w in reraise[:]: - warning = w.message - # Filter out the matching messages - if (re.match(msg, str(warning), re.I) and - issubclass(warning.__class__, cat)): - seen = True - reraise.remove(w) - if not seen and not quiet: - # This filter caught nothing - missing.append((msg, cat.__name__)) - if reraise: - raise AssertionError("unhandled warning %s" % reraise[0]) - if missing: - raise AssertionError("filter (%r, %s) did not catch any warning" % - missing[0]) - - -@contextlib.contextmanager -def check_warnings(*filters, **kwargs): - """Context manager to silence warnings. - - Accept 2-tuples as positional arguments: - ("message regexp", WarningCategory) - - Optional argument: - - if 'quiet' is True, it does not fail if a filter catches nothing - (default True without argument, - default False if some filters are defined) - - Without argument, it defaults to: - check_warnings(("", Warning), quiet=True) - """ - quiet = kwargs.get('quiet') - if not filters: - filters = (("", Warning),) - # Preserve backward compatibility - if quiet is None: - quiet = True - return _filterwarnings(filters, quiet) - - -class CleanImport(object): - """Context manager to force import to return a new module reference. - - This is useful for testing module-level behaviours, such as - the emission of a DeprecationWarning on import. - - Use like this: - - with CleanImport("foo"): - importlib.import_module("foo") # new reference - """ - - def __init__(self, *module_names): - self.original_modules = sys.modules.copy() - for module_name in module_names: - if module_name in sys.modules: - module = sys.modules[module_name] - # It is possible that module_name is just an alias for - # another module (e.g. stub for modules renamed in 3.x). - # In that case, we also need delete the real module to clear - # the import cache. - if module.__name__ != module_name: - del sys.modules[module.__name__] - del sys.modules[module_name] - - def __enter__(self): - return self - - def __exit__(self, *ignore_exc): - sys.modules.update(self.original_modules) - - -class EnvironmentVarGuard(collections.abc.MutableMapping): - - """Class to help protect the environment variable properly. Can be used as - a context manager.""" - - def __init__(self): - self._environ = os.environ - self._changed = {} - - def __getitem__(self, envvar): - return self._environ[envvar] - - def __setitem__(self, envvar, value): - # Remember the initial value on the first access - if envvar not in self._changed: - self._changed[envvar] = self._environ.get(envvar) - self._environ[envvar] = value - - def __delitem__(self, envvar): - # Remember the initial value on the first access - if envvar not in self._changed: - self._changed[envvar] = self._environ.get(envvar) - if envvar in self._environ: - del self._environ[envvar] - - def keys(self): - return self._environ.keys() - - def __iter__(self): - return iter(self._environ) - - def __len__(self): - return len(self._environ) - - def set(self, envvar, value): - self[envvar] = value - - def unset(self, envvar): - del self[envvar] - - def __enter__(self): - return self - - def __exit__(self, *ignore_exc): - for (k, v) in self._changed.items(): - if v is None: - if k in self._environ: - del self._environ[k] - else: - self._environ[k] = v - os.environ = self._environ - - -class DirsOnSysPath(object): - """Context manager to temporarily add directories to sys.path. - - This makes a copy of sys.path, appends any directories given - as positional arguments, then reverts sys.path to the copied - settings when the context ends. - - Note that *all* sys.path modifications in the body of the - context manager, including replacement of the object, - will be reverted at the end of the block. - """ - - def __init__(self, *paths): - self.original_value = sys.path[:] - self.original_object = sys.path - sys.path.extend(paths) - - def __enter__(self): - return self - - def __exit__(self, *ignore_exc): - sys.path = self.original_object - sys.path[:] = self.original_value - - -class TransientResource(object): - - """Raise ResourceDenied if an exception is raised while the context manager - is in effect that matches the specified exception and attributes.""" - - def __init__(self, exc, **kwargs): - self.exc = exc - self.attrs = kwargs - - def __enter__(self): - return self - - def __exit__(self, type_=None, value=None, traceback=None): - """If type_ is a subclass of self.exc and value has attributes matching - self.attrs, raise ResourceDenied. Otherwise let the exception - propagate (if any).""" - if type_ is not None and issubclass(self.exc, type_): - for attr, attr_value in self.attrs.items(): - if not hasattr(value, attr): - break - if getattr(value, attr) != attr_value: - break - else: - raise ResourceDenied("an optional resource is not available") - -# Context managers that raise ResourceDenied when various issues -# with the Internet connection manifest themselves as exceptions. -# XXX deprecate these and use transient_internet() instead -time_out = TransientResource(IOError, errno=errno.ETIMEDOUT) -socket_peer_reset = TransientResource(socket.error, errno=errno.ECONNRESET) -ioerror_peer_reset = TransientResource(IOError, errno=errno.ECONNRESET) - - -@contextlib.contextmanager -def transient_internet(resource_name, *, timeout=30.0, errnos=()): - """Return a context manager that raises ResourceDenied when various issues - with the Internet connection manifest themselves as exceptions.""" - default_errnos = [ - ('ECONNREFUSED', 111), - ('ECONNRESET', 104), - ('EHOSTUNREACH', 113), - ('ENETUNREACH', 101), - ('ETIMEDOUT', 110), - ] - default_gai_errnos = [ - ('EAI_AGAIN', -3), - ('EAI_FAIL', -4), - ('EAI_NONAME', -2), - ('EAI_NODATA', -5), - # Encountered when trying to resolve IPv6-only hostnames - ('WSANO_DATA', 11004), - ] - - denied = ResourceDenied("Resource %r is not available" % resource_name) - captured_errnos = errnos - gai_errnos = [] - if not captured_errnos: - captured_errnos = [getattr(errno, name, num) - for (name, num) in default_errnos] - gai_errnos = [getattr(socket, name, num) - for (name, num) in default_gai_errnos] - - def filter_error(err): - n = getattr(err, 'errno', None) - if (isinstance(err, socket.timeout) or - (isinstance(err, socket.gaierror) and n in gai_errnos) or - n in captured_errnos): - if not verbose: - sys.stderr.write(denied.args[0] + "\n") - raise denied from err - - old_timeout = socket.getdefaulttimeout() - try: - if timeout is not None: - socket.setdefaulttimeout(timeout) - yield - except IOError as err: - # urllib can wrap original socket errors multiple times (!), we must - # unwrap to get at the original error. - while True: - a = err.args - if len(a) >= 1 and isinstance(a[0], IOError): - err = a[0] - # The error can also be wrapped as args[1]: - # except socket.error as msg: - # raise IOError('socket error', msg).with_traceback(sys.exc_info()[2]) - elif len(a) >= 2 and isinstance(a[1], IOError): - err = a[1] - else: - break - filter_error(err) - raise - # XXX should we catch generic exceptions and look for their - # __cause__ or __context__? - finally: - socket.setdefaulttimeout(old_timeout) - - -@contextlib.contextmanager -def captured_output(stream_name): - """Return a context manager used by captured_stdout/stdin/stderr - that temporarily replaces the sys stream *stream_name* with a StringIO.""" - import io - orig_stdout = getattr(sys, stream_name) - setattr(sys, stream_name, io.StringIO()) - try: - yield getattr(sys, stream_name) - finally: - setattr(sys, stream_name, orig_stdout) - -def captured_stdout(): - """Capture the output of sys.stdout: - - with captured_stdout() as s: - print("hello") - self.assertEqual(s.getvalue(), "hello") - """ - return captured_output("stdout") - -def captured_stderr(): - return captured_output("stderr") - -def captured_stdin(): - return captured_output("stdin") - - -def gc_collect(): - """Force as many objects as possible to be collected. - - In non-CPython implementations of Python, this is needed because timely - deallocation is not guaranteed by the garbage collector. (Even in CPython - this can be the case in case of reference cycles.) This means that __del__ - methods may be called later than expected and weakrefs may remain alive for - longer than expected. This function tries its best to force all garbage - objects to disappear. - """ - gc.collect() - if is_jython: - time.sleep(0.1) - gc.collect() - gc.collect() - -@contextlib.contextmanager -def disable_gc(): - have_gc = gc.isenabled() - gc.disable() - try: - yield - finally: - if have_gc: - gc.enable() - - -def python_is_optimized(): - """Find if Python was built with optimizations.""" - cflags = sysconfig.get_config_var('PY_CFLAGS') or '' - final_opt = "" - for opt in cflags.split(): - if opt.startswith('-O'): - final_opt = opt - return final_opt != '' and final_opt != '-O0' - - -#======================================================================= -# Decorator for running a function in a different locale, correctly resetting -# it afterwards. - -def run_with_locale(catstr, *locales): - def decorator(func): - def inner(*args, **kwds): - try: - import locale - category = getattr(locale, catstr) - orig_locale = locale.setlocale(category) - except AttributeError: - # if the test author gives us an invalid category string - raise - except: - # cannot retrieve original locale, so do nothing - locale = orig_locale = None - else: - for loc in locales: - try: - locale.setlocale(category, loc) - break - except: - pass - - # now run the function, resetting the locale on exceptions - try: - return func(*args, **kwds) - finally: - if locale and orig_locale: - locale.setlocale(category, orig_locale) - inner.__name__ = func.__name__ - inner.__doc__ = func.__doc__ - return inner - return decorator - -#======================================================================= -# Big-memory-test support. Separate from 'resources' because memory use -# should be configurable. - -# Some handy shorthands. Note that these are used for byte-limits as well -# as size-limits, in the various bigmem tests -_1M = 1024*1024 -_1G = 1024 * _1M -_2G = 2 * _1G -_4G = 4 * _1G - -MAX_Py_ssize_t = sys.maxsize - -def set_memlimit(limit): - global max_memuse - global real_max_memuse - sizes = { - 'k': 1024, - 'm': _1M, - 'g': _1G, - 't': 1024*_1G, - } - m = re.match(r'(\d+(\.\d+)?) (K|M|G|T)b?$', limit, - re.IGNORECASE | re.VERBOSE) - if m is None: - raise ValueError('Invalid memory limit %r' % (limit,)) - memlimit = int(float(m.group(1)) * sizes[m.group(3).lower()]) - real_max_memuse = memlimit - if memlimit > MAX_Py_ssize_t: - memlimit = MAX_Py_ssize_t - if memlimit < _2G - 1: - raise ValueError('Memory limit %r too low to be useful' % (limit,)) - max_memuse = memlimit - -class _MemoryWatchdog: - """An object which periodically watches the process' memory consumption - and prints it out. - """ - - def __init__(self): - self.procfile = '/proc/{pid}/statm'.format(pid=os.getpid()) - self.started = False - self.thread = None - try: - self.page_size = os.sysconf('SC_PAGESIZE') - except (ValueError, AttributeError): - try: - self.page_size = os.sysconf('SC_PAGE_SIZE') - except (ValueError, AttributeError): - self.page_size = 4096 - - def consumer(self, fd): - HEADER = "l" - header_size = struct.calcsize(HEADER) - try: - while True: - header = os.read(fd, header_size) - if len(header) < header_size: - # Pipe closed on other end - break - data_len, = struct.unpack(HEADER, header) - data = os.read(fd, data_len) - statm = data.decode('ascii') - data = int(statm.split()[5]) - print(" ... process data size: {data:.1f}G" - .format(data=data * self.page_size / (1024 ** 3))) - finally: - os.close(fd) - - def start(self): - if not faulthandler or not hasattr(faulthandler, '_file_watchdog'): - return - try: - rfd = os.open(self.procfile, os.O_RDONLY) - except OSError as e: - warnings.warn('/proc not available for stats: {}'.format(e), - RuntimeWarning) - sys.stderr.flush() - return - pipe_fd, wfd = os.pipe() - # _file_watchdog() doesn't take the GIL in its child thread, and - # therefore collects statistics timely - faulthandler._file_watchdog(rfd, wfd, 1.0) - self.started = True - self.thread = threading.Thread(target=self.consumer, args=(pipe_fd,)) - self.thread.daemon = True - self.thread.start() - - def stop(self): - if not self.started: - return - faulthandler._cancel_file_watchdog() - self.thread.join() - - -def bigmemtest(size, memuse, dry_run=True): - """Decorator for bigmem tests. - - 'minsize' is the minimum useful size for the test (in arbitrary, - test-interpreted units.) 'memuse' is the number of 'bytes per size' for - the test, or a good estimate of it. - - if 'dry_run' is False, it means the test doesn't support dummy runs - when -M is not specified. - """ - def decorator(f): - def wrapper(self): - size = wrapper.size - memuse = wrapper.memuse - if not real_max_memuse: - maxsize = 5147 - else: - maxsize = size - - if ((real_max_memuse or not dry_run) - and real_max_memuse < maxsize * memuse): - raise unittest.SkipTest( - "not enough memory: %.1fG minimum needed" - % (size * memuse / (1024 ** 3))) - - if real_max_memuse and verbose and faulthandler and threading: - print() - print(" ... expected peak memory use: {peak:.1f}G" - .format(peak=size * memuse / (1024 ** 3))) - watchdog = _MemoryWatchdog() - watchdog.start() - else: - watchdog = None - - try: - return f(self, maxsize) - finally: - if watchdog: - watchdog.stop() - - wrapper.size = size - wrapper.memuse = memuse - return wrapper - return decorator - -def bigaddrspacetest(f): - """Decorator for tests that fill the address space.""" - def wrapper(self): - if max_memuse < MAX_Py_ssize_t: - if MAX_Py_ssize_t >= 2**63 - 1 and max_memuse >= 2**31: - raise unittest.SkipTest( - "not enough memory: try a 32-bit build instead") - else: - raise unittest.SkipTest( - "not enough memory: %.1fG minimum needed" - % (MAX_Py_ssize_t / (1024 ** 3))) - else: - return f(self) - return wrapper - -#======================================================================= -# unittest integration. - -class BasicTestRunner: - def run(self, test): - result = unittest.TestResult() - test(result) - return result - -def _id(obj): - return obj - -def requires_resource(resource): - if resource == 'gui' and not _is_gui_available(): - return unittest.skip("resource 'gui' is not available") - if is_resource_enabled(resource): - return _id - else: - return unittest.skip("resource {0!r} is not enabled".format(resource)) - -def cpython_only(test): - """ - Decorator for tests only applicable on CPython. - """ - return impl_detail(cpython=True)(test) - -def impl_detail(msg=None, **guards): - if check_impl_detail(**guards): - return _id - if msg is None: - guardnames, default = _parse_guards(guards) - if default: - msg = "implementation detail not available on {0}" - else: - msg = "implementation detail specific to {0}" - guardnames = sorted(guardnames.keys()) - msg = msg.format(' or '.join(guardnames)) - return unittest.skip(msg) - -def _parse_guards(guards): - # Returns a tuple ({platform_name: run_me}, default_value) - if not guards: - return ({'cpython': True}, False) - is_true = list(guards.values())[0] - assert list(guards.values()) == [is_true] * len(guards) # all True or all False - return (guards, not is_true) - -# Use the following check to guard CPython's implementation-specific tests -- -# or to run them only on the implementation(s) guarded by the arguments. -def check_impl_detail(**guards): - """This function returns True or False depending on the host platform. - Examples: - if check_impl_detail(): # only on CPython (default) - if check_impl_detail(jython=True): # only on Jython - if check_impl_detail(cpython=False): # everywhere except on CPython - """ - guards, default = _parse_guards(guards) - return guards.get(platform.python_implementation().lower(), default) - - -def no_tracing(func): - """Decorator to temporarily turn off tracing for the duration of a test.""" - if not hasattr(sys, 'gettrace'): - return func - else: - @functools.wraps(func) - def wrapper(*args, **kwargs): - original_trace = sys.gettrace() - try: - sys.settrace(None) - return func(*args, **kwargs) - finally: - sys.settrace(original_trace) - return wrapper - - -def refcount_test(test): - """Decorator for tests which involve reference counting. - - To start, the decorator does not run the test if is not run by CPython. - After that, any trace function is unset during the test to prevent - unexpected refcounts caused by the trace function. - - """ - return no_tracing(cpython_only(test)) - - -def _filter_suite(suite, pred): - """Recursively filter test cases in a suite based on a predicate.""" - newtests = [] - for test in suite._tests: - if isinstance(test, unittest.TestSuite): - _filter_suite(test, pred) - newtests.append(test) - else: - if pred(test): - newtests.append(test) - suite._tests = newtests - -def _run_suite(suite): - """Run tests from a unittest.TestSuite-derived class.""" - if verbose: - runner = unittest.TextTestRunner(sys.stdout, verbosity=2, - failfast=failfast) - else: - runner = BasicTestRunner() - - result = runner.run(suite) - if not result.wasSuccessful(): - if len(result.errors) == 1 and not result.failures: - err = result.errors[0][1] - elif len(result.failures) == 1 and not result.errors: - err = result.failures[0][1] - else: - err = "multiple errors occurred" - if not verbose: err += "; run in verbose mode for details" - raise TestFailed(err) - - -def run_unittest(*classes): - """Run tests from unittest.TestCase-derived classes.""" - valid_types = (unittest.TestSuite, unittest.TestCase) - suite = unittest.TestSuite() - for cls in classes: - if isinstance(cls, str): - if cls in sys.modules: - suite.addTest(unittest.findTestCases(sys.modules[cls])) - else: - raise ValueError("str arguments must be keys in sys.modules") - elif isinstance(cls, valid_types): - suite.addTest(cls) - else: - suite.addTest(unittest.makeSuite(cls)) - def case_pred(test): - if match_tests is None: - return True - for name in test.id().split("."): - if fnmatch.fnmatchcase(name, match_tests): - return True - return False - _filter_suite(suite, case_pred) - _run_suite(suite) - - -#======================================================================= -# doctest driver. - -def run_doctest(module, verbosity=None): - """Run doctest on the given module. Return (#failures, #tests). - - If optional argument verbosity is not specified (or is None), pass - support's belief about verbosity on to doctest. Else doctest's - usual behavior is used (it searches sys.argv for -v). - """ - - import doctest - - if verbosity is None: - verbosity = verbose - else: - verbosity = None - - f, t = doctest.testmod(module, verbose=verbosity) - if f: - raise TestFailed("%d of %d doctests failed" % (f, t)) - if verbose: - print('doctest (%s) ... %d tests with zero failures' % - (module.__name__, t)) - return f, t - - -#======================================================================= -# Support for saving and restoring the imported modules. - -def modules_setup(): - return sys.modules.copy(), - -def modules_cleanup(oldmodules): - # Encoders/decoders are registered permanently within the internal - # codec cache. If we destroy the corresponding modules their - # globals will be set to None which will trip up the cached functions. - encodings = [(k, v) for k, v in sys.modules.items() - if k.startswith('encodings.')] - sys.modules.clear() - sys.modules.update(encodings) - # XXX: This kind of problem can affect more than just encodings. In particular - # extension modules (such as _ssl) don't cope with reloading properly. - # Really, test modules should be cleaning out the test specific modules they - # know they added (ala test_runpy) rather than relying on this function (as - # test_importhooks and test_pkg do currently). - # Implicitly imported *real* modules should be left alone (see issue 10556). - sys.modules.update(oldmodules) - -#======================================================================= -# Threading support to prevent reporting refleaks when running regrtest.py -R - -# NOTE: we use thread._count() rather than threading.enumerate() (or the -# moral equivalent thereof) because a threading.Thread object is still alive -# until its __bootstrap() method has returned, even after it has been -# unregistered from the threading module. -# thread._count(), on the other hand, only gets decremented *after* the -# __bootstrap() method has returned, which gives us reliable reference counts -# at the end of a test run. - -def threading_setup(): - if _thread: - return _thread._count(), threading._dangling.copy() - else: - return 1, () - -def threading_cleanup(*original_values): - if not _thread: - return - _MAX_COUNT = 10 - for count in range(_MAX_COUNT): - values = _thread._count(), threading._dangling - if values == original_values: - break - time.sleep(0.1) - gc_collect() - # XXX print a warning in case of failure? - -def reap_threads(func): - """Use this function when threads are being used. This will - ensure that the threads are cleaned up even when the test fails. - If threading is unavailable this function does nothing. - """ - if not _thread: - return func - - @functools.wraps(func) - def decorator(*args): - key = threading_setup() - try: - return func(*args) - finally: - threading_cleanup(*key) - return decorator - -def reap_children(): - """Use this function at the end of test_main() whenever sub-processes - are started. This will help ensure that no extra children (zombies) - stick around to hog resources and create problems when looking - for refleaks. - """ - - # Reap all our dead child processes so we don't leave zombies around. - # These hog resources and might be causing some of the buildbots to die. - if hasattr(os, 'waitpid'): - any_process = -1 - while True: - try: - # This will raise an exception on Windows. That's ok. - pid, status = os.waitpid(any_process, os.WNOHANG) - if pid == 0: - break - except: - break - -@contextlib.contextmanager -def swap_attr(obj, attr, new_val): - """Temporary swap out an attribute with a new object. - - Usage: - with swap_attr(obj, "attr", 5): - ... - - This will set obj.attr to 5 for the duration of the with: block, - restoring the old value at the end of the block. If `attr` doesn't - exist on `obj`, it will be created and then deleted at the end of the - block. - """ - if hasattr(obj, attr): - real_val = getattr(obj, attr) - setattr(obj, attr, new_val) - try: - yield - finally: - setattr(obj, attr, real_val) - else: - setattr(obj, attr, new_val) - try: - yield - finally: - delattr(obj, attr) - -@contextlib.contextmanager -def swap_item(obj, item, new_val): - """Temporary swap out an item with a new object. - - Usage: - with swap_item(obj, "item", 5): - ... - - This will set obj["item"] to 5 for the duration of the with: block, - restoring the old value at the end of the block. If `item` doesn't - exist on `obj`, it will be created and then deleted at the end of the - block. - """ - if item in obj: - real_val = obj[item] - obj[item] = new_val - try: - yield - finally: - obj[item] = real_val - else: - obj[item] = new_val - try: - yield - finally: - del obj[item] - -def strip_python_stderr(stderr): - """Strip the stderr of a Python process from potential debug output - emitted by the interpreter. - - This will typically be run on the result of the communicate() method - of a subprocess.Popen object. - """ - stderr = re.sub(br"\[\d+ refs\]\r?\n?$", b"", stderr).strip() - return stderr - -def args_from_interpreter_flags(): - """Return a list of command-line arguments reproducing the current - settings in sys.flags and sys.warnoptions.""" - flag_opt_map = { - 'bytes_warning': 'b', - 'dont_write_bytecode': 'B', - 'ignore_environment': 'E', - 'no_user_site': 's', - 'no_site': 'S', - 'optimize': 'O', - 'verbose': 'v', - } - args = [] - for flag, opt in flag_opt_map.items(): - v = getattr(sys.flags, flag) - if v > 0: - args.append('-' + opt * v) - for opt in sys.warnoptions: - args.append('-W' + opt) - return args - -#============================================================ -# Support for assertions about logging. -#============================================================ - -class TestHandler(logging.handlers.BufferingHandler): - def __init__(self, matcher): - # BufferingHandler takes a "capacity" argument - # so as to know when to flush. As we're overriding - # shouldFlush anyway, we can set a capacity of zero. - # You can call flush() manually to clear out the - # buffer. - logging.handlers.BufferingHandler.__init__(self, 0) - self.matcher = matcher - - def shouldFlush(self): - return False - - def emit(self, record): - self.format(record) - self.buffer.append(record.__dict__) - - def matches(self, **kwargs): - """ - Look for a saved dict whose keys/values match the supplied arguments. - """ - result = False - for d in self.buffer: - if self.matcher.matches(d, **kwargs): - result = True - break - return result - -class Matcher(object): - - _partial_matches = ('msg', 'message') - - def matches(self, d, **kwargs): - """ - Try to match a single dict with the supplied arguments. - - Keys whose values are strings and which are in self._partial_matches - will be checked for partial (i.e. substring) matches. You can extend - this scheme to (for example) do regular expression matching, etc. - """ - result = True - for k in kwargs: - v = kwargs[k] - dv = d.get(k) - if not self.match_value(k, dv, v): - result = False - break - return result - - def match_value(self, k, dv, v): - """ - Try to match a single stored value (dv) with a supplied value (v). - """ - if type(v) != type(dv): - result = False - elif type(dv) is not str or k not in self._partial_matches: - result = (v == dv) - else: - result = dv.find(v) >= 0 - return result - - -_can_symlink = None -def can_symlink(): - global _can_symlink - if _can_symlink is not None: - return _can_symlink - symlink_path = TESTFN + "can_symlink" - try: - os.symlink(TESTFN, symlink_path) - can = True - except (OSError, NotImplementedError, AttributeError): - can = False - else: - os.remove(symlink_path) - _can_symlink = can - return can - -def skip_unless_symlink(test): - """Skip decorator for tests that require functional symlink""" - ok = can_symlink() - msg = "Requires functional symlink implementation" - return test if ok else unittest.skip(msg)(test) - -def patch(test_instance, object_to_patch, attr_name, new_value): - """Override 'object_to_patch'.'attr_name' with 'new_value'. - - Also, add a cleanup procedure to 'test_instance' to restore - 'object_to_patch' value for 'attr_name'. - The 'attr_name' should be a valid attribute for 'object_to_patch'. - - """ - # check that 'attr_name' is a real attribute for 'object_to_patch' - # will raise AttributeError if it does not exist - getattr(object_to_patch, attr_name) - - # keep a copy of the old value - attr_is_local = False - try: - old_value = object_to_patch.__dict__[attr_name] - except (AttributeError, KeyError): - old_value = getattr(object_to_patch, attr_name, None) - else: - attr_is_local = True - - # restore the value when the test is done - def cleanup(): - if attr_is_local: - setattr(object_to_patch, attr_name, old_value) - else: - delattr(object_to_patch, attr_name) - - test_instance.addCleanup(cleanup) - - # actually override the attribute - setattr(object_to_patch, attr_name, new_value) |