/usr/lib/python3/dist-packages/twisted/trial/test/test_warning.py is in python3-twisted-experimental 13.2.0-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | # Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for Trial's interaction with the Python warning system.
"""
from __future__ import division, absolute_import
import sys, warnings
from unittest import TestResult
from twisted.python.compat import NativeStringIO as StringIO
from twisted.python.filepath import FilePath
from twisted.trial.unittest import (
SynchronousTestCase, _collectWarnings, _setWarningRegistryToNone)
class Mask(object):
"""
Hide a test case definition from trial's automatic discovery mechanism.
"""
class MockTests(SynchronousTestCase):
"""
A test case which is used by L{FlushWarningsTests} to verify behavior
which cannot be verified by code inside a single test method.
"""
message = "some warning text"
category = UserWarning
def test_unflushed(self):
"""
Generate a warning and don't flush it.
"""
warnings.warn(self.message, self.category)
def test_flushed(self):
"""
Generate a warning and flush it.
"""
warnings.warn(self.message, self.category)
self.assertEqual(len(self.flushWarnings()), 1)
class FlushWarningsTests(SynchronousTestCase):
"""
Tests for C{flushWarnings}, an API for examining the warnings
emitted so far in a test.
"""
def assertDictSubset(self, set, subset):
"""
Assert that all the keys present in C{subset} are also present in
C{set} and that the corresponding values are equal.
"""
for k, v in subset.items():
self.assertEqual(set[k], v)
def assertDictSubsets(self, sets, subsets):
"""
For each pair of corresponding elements in C{sets} and C{subsets},
assert that the element from C{subsets} is a subset of the element from
C{sets}.
"""
self.assertEqual(len(sets), len(subsets))
for a, b in zip(sets, subsets):
self.assertDictSubset(a, b)
def test_none(self):
"""
If no warnings are emitted by a test, C{flushWarnings} returns an empty
list.
"""
self.assertEqual(self.flushWarnings(), [])
def test_several(self):
"""
If several warnings are emitted by a test, C{flushWarnings} returns a
list containing all of them.
"""
firstMessage = "first warning message"
firstCategory = UserWarning
warnings.warn(message=firstMessage, category=firstCategory)
secondMessage = "second warning message"
secondCategory = RuntimeWarning
warnings.warn(message=secondMessage, category=secondCategory)
self.assertDictSubsets(
self.flushWarnings(),
[{'category': firstCategory, 'message': firstMessage},
{'category': secondCategory, 'message': secondMessage}])
def test_repeated(self):
"""
The same warning triggered twice from the same place is included twice
in the list returned by C{flushWarnings}.
"""
message = "the message"
category = RuntimeWarning
for i in range(2):
warnings.warn(message=message, category=category)
self.assertDictSubsets(
self.flushWarnings(),
[{'category': category, 'message': message}] * 2)
def test_cleared(self):
"""
After a particular warning event has been returned by C{flushWarnings},
it is not returned by subsequent calls.
"""
message = "the message"
category = RuntimeWarning
warnings.warn(message=message, category=category)
self.assertDictSubsets(
self.flushWarnings(),
[{'category': category, 'message': message}])
self.assertEqual(self.flushWarnings(), [])
def test_unflushed(self):
"""
Any warnings emitted by a test which are not flushed are emitted to the
Python warning system.
"""
result = TestResult()
case = Mask.MockTests('test_unflushed')
case.run(result)
warningsShown = self.flushWarnings([Mask.MockTests.test_unflushed])
self.assertEqual(warningsShown[0]['message'], 'some warning text')
self.assertIdentical(warningsShown[0]['category'], UserWarning)
where = type(case).test_unflushed.__code__
filename = where.co_filename
# If someone edits MockTests.test_unflushed, the value added to
# firstlineno might need to change.
lineno = where.co_firstlineno + 4
self.assertEqual(warningsShown[0]['filename'], filename)
self.assertEqual(warningsShown[0]['lineno'], lineno)
self.assertEqual(len(warningsShown), 1)
def test_flushed(self):
"""
Any warnings emitted by a test which are flushed are not emitted to the
Python warning system.
"""
result = TestResult()
case = Mask.MockTests('test_flushed')
output = StringIO()
monkey = self.patch(sys, 'stdout', output)
case.run(result)
monkey.restore()
self.assertEqual(output.getvalue(), "")
def test_warningsConfiguredAsErrors(self):
"""
If a warnings filter has been installed which turns warnings into
exceptions, tests have an error added to the reporter for them for each
unflushed warning.
"""
class CustomWarning(Warning):
pass
result = TestResult()
case = Mask.MockTests('test_unflushed')
case.category = CustomWarning
originalWarnings = warnings.filters[:]
try:
warnings.simplefilter('error')
case.run(result)
self.assertEqual(len(result.errors), 1)
self.assertIdentical(result.errors[0][0], case)
self.assertTrue(
# Different python versions differ in whether they report the
# fully qualified class name or just the class name.
result.errors[0][1].splitlines()[-1].endswith(
"CustomWarning: some warning text"))
finally:
warnings.filters[:] = originalWarnings
def test_flushedWarningsConfiguredAsErrors(self):
"""
If a warnings filter has been installed which turns warnings into
exceptions, tests which emit those warnings but flush them do not have
an error added to the reporter.
"""
class CustomWarning(Warning):
pass
result = TestResult()
case = Mask.MockTests('test_flushed')
case.category = CustomWarning
originalWarnings = warnings.filters[:]
try:
warnings.simplefilter('error')
case.run(result)
self.assertEqual(result.errors, [])
finally:
warnings.filters[:] = originalWarnings
def test_multipleFlushes(self):
"""
Any warnings emitted after a call to C{flushWarnings} can be flushed by
another call to C{flushWarnings}.
"""
warnings.warn("first message")
self.assertEqual(len(self.flushWarnings()), 1)
warnings.warn("second message")
self.assertEqual(len(self.flushWarnings()), 1)
def test_filterOnOffendingFunction(self):
"""
The list returned by C{flushWarnings} includes only those
warnings which refer to the source of the function passed as the value
for C{offendingFunction}, if a value is passed for that parameter.
"""
firstMessage = "first warning text"
firstCategory = UserWarning
def one():
warnings.warn(firstMessage, firstCategory, stacklevel=1)
secondMessage = "some text"
secondCategory = RuntimeWarning
def two():
warnings.warn(secondMessage, secondCategory, stacklevel=1)
one()
two()
self.assertDictSubsets(
self.flushWarnings(offendingFunctions=[one]),
[{'category': firstCategory, 'message': firstMessage}])
self.assertDictSubsets(
self.flushWarnings(offendingFunctions=[two]),
[{'category': secondCategory, 'message': secondMessage}])
def test_functionBoundaries(self):
"""
Verify that warnings emitted at the very edges of a function are still
determined to be emitted from that function.
"""
def warner():
warnings.warn("first line warning")
warnings.warn("internal line warning")
warnings.warn("last line warning")
warner()
self.assertEqual(
len(self.flushWarnings(offendingFunctions=[warner])), 3)
def test_invalidFilter(self):
"""
If an object which is neither a function nor a method is included in the
C{offendingFunctions} list, C{flushWarnings} raises L{ValueError}. Such
a call flushes no warnings.
"""
warnings.warn("oh no")
self.assertRaises(ValueError, self.flushWarnings, [None])
self.assertEqual(len(self.flushWarnings()), 1)
def test_missingSource(self):
"""
Warnings emitted by a function the source code of which is not
available can still be flushed.
"""
package = FilePath(self.mktemp().encode('utf-8')).child(b'twisted_private_helper')
package.makedirs()
package.child(b'__init__.py').setContent(b'')
package.child(b'missingsourcefile.py').setContent(b'''
import warnings
def foo():
warnings.warn("oh no")
''')
pathEntry = package.parent().path.decode('utf-8')
sys.path.insert(0, pathEntry)
self.addCleanup(sys.path.remove, pathEntry)
from twisted_private_helper import missingsourcefile
self.addCleanup(sys.modules.pop, 'twisted_private_helper')
self.addCleanup(sys.modules.pop, missingsourcefile.__name__)
package.child(b'missingsourcefile.py').remove()
missingsourcefile.foo()
self.assertEqual(len(self.flushWarnings([missingsourcefile.foo])), 1)
def test_renamedSource(self):
"""
Warnings emitted by a function defined in a file which has been renamed
since it was initially compiled can still be flushed.
This is testing the code which specifically supports working around the
unfortunate behavior of CPython to write a .py source file name into
the .pyc files it generates and then trust that it is correct in
various places. If source files are renamed, .pyc files may not be
regenerated, but they will contain incorrect filenames.
"""
package = FilePath(self.mktemp().encode('utf-8')).child(b'twisted_private_helper')
package.makedirs()
package.child(b'__init__.py').setContent(b'')
package.child(b'module.py').setContent(b'''
import warnings
def foo():
warnings.warn("oh no")
''')
pathEntry = package.parent().path.decode('utf-8')
sys.path.insert(0, pathEntry)
self.addCleanup(sys.path.remove, pathEntry)
# Import it to cause pycs to be generated
from twisted_private_helper import module
# Clean up the state resulting from that import; we're not going to use
# this module, so it should go away.
del sys.modules['twisted_private_helper']
del sys.modules[module.__name__]
# Some Python versions have extra state related to the just
# imported/renamed package. Clean it up too. See also
# http://bugs.python.org/issue15912
try:
from importlib import invalidate_caches
except ImportError:
pass
else:
invalidate_caches()
# Rename the source directory
package.moveTo(package.sibling(b'twisted_renamed_helper'))
# Import the newly renamed version
from twisted_renamed_helper import module
self.addCleanup(sys.modules.pop, 'twisted_renamed_helper')
self.addCleanup(sys.modules.pop, module.__name__)
# Generate the warning
module.foo()
# Flush it
self.assertEqual(len(self.flushWarnings([module.foo])), 1)
class FakeWarning(Warning):
pass
class CollectWarningsTests(SynchronousTestCase):
"""
Tests for L{_collectWarnings}.
"""
def test_callsObserver(self):
"""
L{_collectWarnings} calls the observer with each emitted warning.
"""
firstMessage = "dummy calls observer warning"
secondMessage = firstMessage[::-1]
events = []
def f():
events.append('call')
warnings.warn(firstMessage)
warnings.warn(secondMessage)
events.append('returning')
_collectWarnings(events.append, f)
self.assertEqual(events[0], 'call')
self.assertEqual(events[1].message, firstMessage)
self.assertEqual(events[2].message, secondMessage)
self.assertEqual(events[3], 'returning')
self.assertEqual(len(events), 4)
def test_suppresses(self):
"""
Any warnings emitted by a call to a function passed to
L{_collectWarnings} are not actually emitted to the warning system.
"""
output = StringIO()
self.patch(sys, 'stdout', output)
_collectWarnings(lambda x: None, warnings.warn, "text")
self.assertEqual(output.getvalue(), "")
def test_callsFunction(self):
"""
L{_collectWarnings} returns the result of calling the callable passed to
it with the parameters given.
"""
arguments = []
value = object()
def f(*args, **kwargs):
arguments.append((args, kwargs))
return value
result = _collectWarnings(lambda x: None, f, 1, 'a', b=2, c='d')
self.assertEqual(arguments, [((1, 'a'), {'b': 2, 'c': 'd'})])
self.assertIdentical(result, value)
def test_duplicateWarningCollected(self):
"""
Subsequent emissions of a warning from a particular source site can be
collected by L{_collectWarnings}. In particular, the per-module
emitted-warning cache should be bypassed (I{__warningregistry__}).
"""
# Make sure the worst case is tested: if __warningregistry__ isn't in a
# module's globals, then the warning system will add it and start using
# it to avoid emitting duplicate warnings. Delete __warningregistry__
# to ensure that even modules which are first imported as a test is
# running still interact properly with the warning system.
global __warningregistry__
del __warningregistry__
def f():
warnings.warn("foo")
warnings.simplefilter('default')
f()
events = []
_collectWarnings(events.append, f)
self.assertEqual(len(events), 1)
self.assertEqual(events[0].message, "foo")
self.assertEqual(len(self.flushWarnings()), 1)
def test_immutableObject(self):
"""
L{_collectWarnings}'s behavior is not altered by the presence of an
object which cannot have attributes set on it as a value in
C{sys.modules}.
"""
key = object()
sys.modules[key] = key
self.addCleanup(sys.modules.pop, key)
self.test_duplicateWarningCollected()
def test_setWarningRegistryChangeWhileIterating(self):
"""
If the dictionary passed to L{_setWarningRegistryToNone} changes size
partway through the process, C{_setWarningRegistryToNone} continues to
set C{__warningregistry__} to C{None} on the rest of the values anyway.
This might be caused by C{sys.modules} containing something that's not
really a module and imports things on setattr. py.test does this, as
does L{twisted.python.deprecate.deprecatedModuleAttribute}.
"""
d = {}
class A(object):
def __init__(self, key):
self.__dict__['_key'] = key
def __setattr__(self, value, item):
d[self._key] = None
key1 = object()
key2 = object()
d[key1] = A(key2)
key3 = object()
key4 = object()
d[key3] = A(key4)
_setWarningRegistryToNone(d)
# If both key2 and key4 were added, then both A instanced were
# processed.
self.assertEqual(set([key1, key2, key3, key4]), set(d.keys()))
|