"""Supporting definitions for the Python regression tests."""

if __name__ != 'test.test_support':

    raise ImportError('test_support must be imported from the test package')

import contextlib

import errno

import socket

import sys

import os

import shutil

import warnings

import unittest

__all__ = ["Error", "TestFailed", "TestSkipped", "ResourceDenied", "import_module",

           "verbose", "use_resources", "max_memuse", "record_original_stdout",

           "get_original_stdout", "unload", "unlink", "rmtree", "forget",

           "is_resource_enabled", "requires", "find_unused_port", "bind_port",

           "fcmp", "have_unicode", "is_jython", "TESTFN", "HOST", "FUZZ",

           "findfile", "verify", "vereq", "sortdict", "check_syntax_error",

           "open_urlresource", "check_warnings", "CleanImport",

           "EnvironmentVarGuard", "captured_output",

           "captured_stdout", "TransientResource", "transient_internet",

           "run_with_locale", "set_memlimit", "bigmemtest", "bigaddrspacetest",

           "BasicTestRunner", "run_unittest", "run_doctest", "threading_setup",

           "threading_cleanup", "reap_children"]

class Error(Exception):

    """Base class for regression test exceptions."""

class TestFailed(Error):

    """Test failed."""

class TestSkipped(Error):

    """Test skipped.

    This can be raised to indicate that a test was deliberatly

    skipped, but not because a feature wasn't available.  For

    example, if some resource can't be used, such as the network

    appears to be unavailable, this should be raised instead of

    TestFailed.

    """

class ResourceDenied(TestSkipped):

    """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.

    """

def import_module(name, deprecated=False):

    """Import the module to be tested, raising TestSkipped if it is not

    available."""

    with warnings.catch_warnings():

        if deprecated:

            warnings.filterwarnings("ignore", ".+ (module|package)",

                                    DeprecationWarning)

        try:

            module = __import__(name, level=0)

        except ImportError:

            raise TestSkipped("No module named " + name)

        else:

            return module

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

# _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:

        pass

def rmtree(path):

    try:

        shutil.rmtree(path)

    except OSError, e:

        # Unix returns ENOENT, Windows returns ESRCH.

        if e.errno not in (errno.ENOENT, errno.ESRCH):

            raise

def forget(modname):

    '''"Forget" a module was ever imported by removing it from sys.modules and

    deleting any .pyc and .pyo files.'''

    unload(modname)

    for dirname in sys.path:

        unlink(os.path.join(dirname, modname + os.extsep + 'pyc'))

        # Deleting the .pyo file cannot be within the 'try' for the .pyc since

        # the chance exists that there is no .pyc (and thus the 'try' statement

        # is exited) but there is a .pyo file.

        unlink(os.path.join(dirname, modname + os.extsep + 'pyo'))

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."""

    # see if the caller's module is __main__ - if so, treat as if

    # the resource was set

    if sys._getframe().f_back.f_globals.get("__name__") == "__main__":

        return

    if not is_resource_enabled(resource):

        if msg is None:

            msg = "Use of the `%s' resource not enabled" % resource

        raise ResourceDenied(msg)

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

FUZZ = 1e-6

def fcmp(x, y): # fuzzy comparison function

    if isinstance(x, float) or isinstance(y, float):

        try:

            fuzz = (abs(x) + abs(y)) * FUZZ

            if abs(x-y) <= fuzz:

                return 0

        except:

            pass

    elif type(x) == type(y) and isinstance(x, (tuple, list)):

        for i in range(min(len(x), len(y))):

            outcome = fcmp(x[i], y[i])

            if outcome != 0:

                return outcome

        return (len(x) > len(y)) - (len(x) < len(y))

    return (x > y) - (x < y)

try:

    unicode

    have_unicode = True

except NameError:

    have_unicode = False

is_jython = sys.platform.startswith('java')

# Filename used for testing

if os.name == 'java':

    # Jython disallows @ in module names

    TESTFN = '$test'

elif os.name == 'riscos':

    TESTFN = 'testfile'

else:

    TESTFN = '@test'

    # Unicode name only used if TEST_FN_ENCODING exists for the platform.

    if have_unicode:

        # Assuming sys.getfilesystemencoding()!=sys.getdefaultencoding()

        # TESTFN_UNICODE is a filename that can be encoded using the

        # file system encoding, but *not* with the default (ascii) encoding

        if isinstance('', unicode):

            # python -U

            # XXX perhaps unicode() should accept Unicode strings?

            TESTFN_UNICODE = "@test-\xe0\xf2"

        else:

            # 2 latin characters.

            TESTFN_UNICODE = unicode("@test-\xe0\xf2", "latin-1")

        TESTFN_ENCODING = sys.getfilesystemencoding()

        # TESTFN_UNICODE_UNENCODEABLE is a filename that should *not* be

        # able to be encoded by *either* the default or filesystem encoding.

        # This test really only makes sense on Windows NT platforms

        # which have special Unicode support in posixmodule.

        if (not hasattr(sys, "getwindowsversion") or

                sys.getwindowsversion()[3] < 2): #  0=win32s or 1=9x/ME

            TESTFN_UNICODE_UNENCODEABLE = None

        else:

            # Japanese characters (I think - from bug 846133)

            TESTFN_UNICODE_UNENCODEABLE = eval('u"@test-\u5171\u6709\u3055\u308c\u308b"')

            try:

                # XXX - Note - should be using TESTFN_ENCODING here - but for

                # Windows, "mbcs" currently always operates as if in

                # errors=ignore' mode - hence we get '?' characters rather than

                # the exception.  'Latin1' operates as we expect - ie, fails.

                # See [ 850997 ] mbcs encoding ignores errors

                TESTFN_UNICODE_UNENCODEABLE.encode("Latin1")

            except UnicodeEncodeError:

                pass

            else:

                print \

                'WARNING: The filename %r CAN be encoded by the filesystem.  ' \

                'Unicode filename tests may not be effective' \

                % TESTFN_UNICODE_UNENCODEABLE

# Make sure we can write to TESTFN, try in /tmp if we can't

fp = None

try:

    fp = open(TESTFN, 'w+')

except IOError:

    TMP_TESTFN = os.path.join('/tmp', TESTFN)

    try:

        fp = open(TMP_TESTFN, 'w+')

        TESTFN = TMP_TESTFN

        del TMP_TESTFN

    except IOError:

        print ('WARNING: tests will fail, unable to write to: %s or %s' %

                (TESTFN, TMP_TESTFN))

if fp is not None:

    fp.close()

    unlink(TESTFN)

del fp

def findfile(file, here=__file__):

    """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

    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 verify(condition, reason='test failed'):

    """Verify that condition is true. If not, raise TestFailed.

       The optional argument reason can be given to provide

       a better error text.

    """

    if not condition:

        raise TestFailed(reason)

def vereq(a, b):

    """Raise TestFailed if a == b is false.

    This is better than verify(a == b) because, in case of failure, the

    error message incorporates repr(a) and repr(b) so you can see the

    inputs.

    Note that "not (a == b)" isn't necessarily the same as "a != b"; the

    former is tested.

    """

    if not (a == b):

        raise TestFailed("%r == %r" % (a, b))

def sortdict(dict):

    "Like repr(dict), but in sorted order."

    items = dict.items()

    items.sort()

    reprpairs = ["%r: %r" % pair for pair in items]

    withcommas = ", ".join(reprpairs)

    return "{%s}" % withcommas

def check_syntax_error(testcase, statement):

    try:

        compile(statement, '<test string>', 'exec')

    except SyntaxError:

        pass

    else:

        testcase.fail('Missing SyntaxError: "%s"' % statement)

def open_urlresource(url):

    import urllib, urlparse

    requires('urlfetch')

    filename = urlparse.urlparse(url)[2].split('/')[-1] # '/': it's URL!

    for path in [os.path.curdir, os.path.pardir]:

        fn = os.path.join(path, filename)

        if os.path.exists(fn):

            return open(fn)

    print >> get_original_stdout(), '\tfetching %s ...' % url

    fn, _ = urllib.urlretrieve(url, filename)

    return open(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

    def __getattr__(self, attr):

        if self.warnings:

            return getattr(self.warnings[-1], attr)

        elif attr in warnings.WarningMessage._WARNING_DETAILS:

            return None

        raise AttributeError("%r has no attribute %r" % (self, attr))

    def reset(self):

        del self.warnings[:]

@contextlib.contextmanager

def check_warnings():

    with warnings.catch_warnings(record=True) as w:

        yield WarningsRecorder(w)

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"):

            __import__("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(object):

    """Class to help protect the environment variable properly.  Can be used as

    a context manager."""

    def __init__(self):

        self._environ = os.environ

        self._unset = set()

        self._reset = dict()

    def set(self, envvar, value):

        if envvar not in self._environ:

            self._unset.add(envvar)

        else:

            self._reset[envvar] = self._environ[envvar]

        self._environ[envvar] = value

    def unset(self, envvar):

        if envvar in self._environ:

            self._reset[envvar] = self._environ[envvar]

            del self._environ[envvar]

    def __enter__(self):

        return self

    def __exit__(self, *ignore_exc):

        for envvar, value in self._reset.iteritems():

            self._environ[envvar] = value

        for unset in self._unset:

            del self._environ[unset]

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.iteritems():

                if not hasattr(value, attr):

                    break

                if getattr(value, attr) != attr_value:

                    break

            else:

                raise ResourceDenied("an optional resource is not available")

def transient_internet():

    """Return a context manager that raises ResourceDenied when various issues

    with the Internet connection manifest themselves as exceptions."""

    time_out = TransientResource(IOError, errno=errno.ETIMEDOUT)

    socket_peer_reset = TransientResource(socket.error, errno=errno.ECONNRESET)

    ioerror_peer_reset = TransientResource(IOError, errno=errno.ECONNRESET)

    return contextlib.nested(time_out, socket_peer_reset, ioerror_peer_reset)

@contextlib.contextmanager

def captured_output(stream_name):

    """Run the 'with' statement body using a StringIO object in place of a

    specific attribute on the sys module.

    Example use (with 'stream_name=stdout')::

       with captured_stdout() as s:

           print "hello"

       assert s.getvalue() == "hello"

    """

    import StringIO

    orig_stdout = getattr(sys, stream_name)

    setattr(sys, stream_name, StringIO.StringIO())

    try:

        yield getattr(sys, stream_name)

    finally:

        setattr(sys, stream_name, orig_stdout)

def captured_stdout():

    return captured_output("stdout")

#=======================================================================

# Decorator for running a function in a different locale, correctly resetting

# it afterwards.