support.py (original) (raw)

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"""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 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)[](#l433) 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 " [](#l467) "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 " [](#l471) "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[](#l528) 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 [](#l559) + 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, '', '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 = 10241024 _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 def start(self): try: f = open(self.procfile, 'r') except OSError as e: warnings.warn('/proc not available for stats: {}'.format(e), RuntimeWarning) sys.stderr.flush() return watchdog_script = findfile("memory_watchdog.py") self.mem_watchdog = subprocess.Popen([sys.executable, watchdog_script], stdin=f, stderr=subprocess.DEVNULL) f.close() self.started = True def stop(self): if self.started: self.mem_watchdog.terminate() self.mem_watchdog.wait() 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: 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 >= 263 - 1 and max_memuse >= 231: 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, optionflags=0): """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, optionflags=optionflags) 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', 'hash_randomization': 'R', '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)