summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_support.py
blob: 5b2176e009a429476339e5e101410994db638218 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
"""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 os.path
import warnings
import types
import unittest

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.
    """

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.)

# _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 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 + '.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 + '.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)

def bind_port(sock, host='', preferred_port=54321):
    """Try to bind the sock to a port.  If we are running multiple
    tests and we don't try multiple ports, the test can fails.  This
    makes the test more robust."""

    # some random ports that hopefully no one is listening on.
    for port in [preferred_port, 9907, 10243, 32999]:
        try:
            sock.bind((host, port))
            return port
        except socket.error as e:
            (err, msg) = e.args
            if err != errno.EADDRINUSE:
                raise
            print('  WARNING: failed to listen on port %d, trying another' % port, file=sys.__stderr__)
    raise TestFailed('unable to find port to listen on')

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:
    str
    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'
else:
    TESTFN = '@test'

    # 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
    TESTFN_UNICODE = "@test-\xe0\xf2"
    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 = "@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 = sorted(dict.items())
    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, *args, **kw):
    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, *args, **kw)

    print('\tfetching %s ...' % url, file=get_original_stdout())
    fn, _ = urllib.urlretrieve(url, filename)
    return open(fn, *args, **kw)


class WarningMessage(object):
    "Holds the result of the latest showwarning() call"
    def __init__(self):
        self.message = None
        self.category = None
        self.filename = None
        self.lineno = None

    def _showwarning(self, message, category, filename, lineno, file=None):
        self.message = message
        self.category = category
        self.filename = filename
        self.lineno = lineno

@contextlib.contextmanager
def catch_warning():
    """
    Guard the warnings filter from being permanently changed and record the
    data of the last warning that has been issued.

    Use like this:

        with catch_warning() as w:
            warnings.warn("foo")
            assert str(w.message) == "foo"
    """
    warning = WarningMessage()
    original_filters = warnings.filters[:]
    original_showwarning = warnings.showwarning
    warnings.showwarning = warning._showwarning
    try:
        yield warning
    finally:
        warnings.showwarning = original_showwarning
        warnings.filters = original_filters

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.items():
            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.items():
                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_stdout():
    """Run the with statement body using a StringIO object as sys.stdout.
    Example use::

       with captured_stdout() as s:
           print "hello"
       assert s.getvalue() == "hello"
    """
    import io
    orig_stdout = sys.stdout
    sys.stdout = io.StringIO()
    yield sys.stdout
    sys.stdout = orig_stdout


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

MAX_Py_ssize_t = sys.maxsize

def set_memlimit(limit):
    import re
    global 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()])
    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

def bigmemtest(minsize, memuse, overhead=5*_1M):
    """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. 'overhead' specifies fixed overhead,
    independant of the testsize, and defaults to 5Mb.

    The decorator tries to guess a good value for 'size' and passes it to
    the decorated test function. If minsize * memuse is more than the
    allowed memory use (as defined by max_memuse), the test is skipped.
    Otherwise, minsize is adjusted upward to use up to max_memuse.
    """
    def decorator(f):
        def wrapper(self):
            if not max_memuse:
                # If max_memuse is 0 (the default),
                # we still want to run the tests with size set to a few kb,
                # to make sure they work. We still want to avoid using
                # too much memory, though, but we do that noisily.
                maxsize = 5147
                self.failIf(maxsize * memuse + overhead > 20 * _1M)
            else:
                maxsize = int((max_memuse - overhead) / memuse)
                if maxsize < minsize:
                    # Really ought to print 'test skipped' or something
                    if verbose:
                        sys.stderr.write("Skipping %s because of memory "
                                         "constraint\n" % (f.__name__,))
                    return
                # Try to keep some breathing room in memory use
                maxsize = max(maxsize - 50 * _1M, minsize)
            return f(self, maxsize)
        wrapper.minsize = minsize
        wrapper.memuse = memuse
        wrapper.overhead = overhead
        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 verbose:
                sys.stderr.write("Skipping %s because of memory "
                                 "constraint\n" % (f.__name__,))
        else:
            return f(self)
    return wrapper

#=======================================================================
# unittest integration.

class BasicTestRunner:
    def run(self, test):
        result = unittest.TestResult()
        test(result)
        return result


def _run_suite(suite):
    """Run tests from a unittest.TestSuite-derived class."""
    if verbose:
        runner = unittest.TextTestRunner(sys.stdout, verbosity=2)
    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:
            msg = "errors occurred; run in verbose mode for details"
            raise TestFailed(msg)
        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, basestring):
            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))
    _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
    test_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

    # Direct doctest output (normally just errors) to real stdout; doctest
    # output shouldn't be compared by regrtest.
    save_stdout = sys.stdout
    sys.stdout = get_original_stdout()
    try:
        f, t = doctest.testmod(module, verbose=verbosity)
        if f:
            raise TestFailed("%d of %d doctests failed" % (f, t))
    finally:
        sys.stdout = save_stdout
    if verbose:
        print('doctest (%s) ... %d tests with zero failures' % (module.__name__, t))
    return f, t

#=======================================================================
# Threading support to prevent reporting refleaks when running regrtest.py -R

def threading_setup():
    import threading
    return len(threading._active), len(threading._limbo)

def threading_cleanup(num_active, num_limbo):
    import threading
    import time

    _MAX_COUNT = 10
    count = 0
    while len(threading._active) != num_active and count < _MAX_COUNT:
        count += 1
        time.sleep(0.1)

    count = 0
    while len(threading._limbo) != num_limbo and count < _MAX_COUNT:
        count += 1
        time.sleep(0.1)

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