Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 1 | """Unit tests for contextlib.py, and other context managers.""" |
| 2 | |
R. David Murray | 378c0cf | 2010-02-24 01:46:21 +0000 | [diff] [blame] | 3 | import sys |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 4 | import tempfile |
| 5 | import unittest |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 6 | from contextlib import * # Tests __all__ |
Benjamin Peterson | ee8712c | 2008-05-20 21:35:26 +0000 | [diff] [blame] | 7 | from test import support |
Victor Stinner | 45df820 | 2010-04-28 22:31:17 +0000 | [diff] [blame] | 8 | try: |
| 9 | import threading |
| 10 | except ImportError: |
| 11 | threading = None |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 12 | |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 13 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 14 | class ContextManagerTestCase(unittest.TestCase): |
| 15 | |
| 16 | def test_contextmanager_plain(self): |
| 17 | state = [] |
| 18 | @contextmanager |
| 19 | def woohoo(): |
| 20 | state.append(1) |
| 21 | yield 42 |
| 22 | state.append(999) |
| 23 | with woohoo() as x: |
| 24 | self.assertEqual(state, [1]) |
| 25 | self.assertEqual(x, 42) |
| 26 | state.append(x) |
| 27 | self.assertEqual(state, [1, 42, 999]) |
| 28 | |
| 29 | def test_contextmanager_finally(self): |
| 30 | state = [] |
| 31 | @contextmanager |
| 32 | def woohoo(): |
| 33 | state.append(1) |
| 34 | try: |
| 35 | yield 42 |
| 36 | finally: |
| 37 | state.append(999) |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 38 | with self.assertRaises(ZeroDivisionError): |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 39 | with woohoo() as x: |
| 40 | self.assertEqual(state, [1]) |
| 41 | self.assertEqual(x, 42) |
| 42 | state.append(x) |
| 43 | raise ZeroDivisionError() |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 44 | self.assertEqual(state, [1, 42, 999]) |
| 45 | |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 46 | def test_contextmanager_no_reraise(self): |
| 47 | @contextmanager |
| 48 | def whee(): |
| 49 | yield |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 50 | ctx = whee() |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 51 | ctx.__enter__() |
| 52 | # Calling __exit__ should not result in an exception |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 53 | self.assertFalse(ctx.__exit__(TypeError, TypeError("foo"), None)) |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 54 | |
| 55 | def test_contextmanager_trap_yield_after_throw(self): |
| 56 | @contextmanager |
| 57 | def whoo(): |
| 58 | try: |
| 59 | yield |
| 60 | except: |
| 61 | yield |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 62 | ctx = whoo() |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 63 | ctx.__enter__() |
| 64 | self.assertRaises( |
| 65 | RuntimeError, ctx.__exit__, TypeError, TypeError("foo"), None |
| 66 | ) |
| 67 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 68 | def test_contextmanager_except(self): |
| 69 | state = [] |
| 70 | @contextmanager |
| 71 | def woohoo(): |
| 72 | state.append(1) |
| 73 | try: |
| 74 | yield 42 |
Guido van Rossum | b940e11 | 2007-01-10 16:19:56 +0000 | [diff] [blame] | 75 | except ZeroDivisionError as e: |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 76 | state.append(e.args[0]) |
| 77 | self.assertEqual(state, [1, 42, 999]) |
| 78 | with woohoo() as x: |
| 79 | self.assertEqual(state, [1]) |
| 80 | self.assertEqual(x, 42) |
| 81 | state.append(x) |
| 82 | raise ZeroDivisionError(999) |
| 83 | self.assertEqual(state, [1, 42, 999]) |
| 84 | |
R. David Murray | 378c0cf | 2010-02-24 01:46:21 +0000 | [diff] [blame] | 85 | def _create_contextmanager_attribs(self): |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 86 | def attribs(**kw): |
| 87 | def decorate(func): |
| 88 | for k,v in kw.items(): |
| 89 | setattr(func,k,v) |
| 90 | return func |
| 91 | return decorate |
| 92 | @contextmanager |
| 93 | @attribs(foo='bar') |
| 94 | def baz(spam): |
| 95 | """Whee!""" |
R. David Murray | 378c0cf | 2010-02-24 01:46:21 +0000 | [diff] [blame] | 96 | return baz |
| 97 | |
| 98 | def test_contextmanager_attribs(self): |
| 99 | baz = self._create_contextmanager_attribs() |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 100 | self.assertEqual(baz.__name__,'baz') |
| 101 | self.assertEqual(baz.foo, 'bar') |
R. David Murray | 378c0cf | 2010-02-24 01:46:21 +0000 | [diff] [blame] | 102 | |
| 103 | @unittest.skipIf(sys.flags.optimize >= 2, |
| 104 | "Docstrings are omitted with -O2 and above") |
| 105 | def test_contextmanager_doc_attrib(self): |
| 106 | baz = self._create_contextmanager_attribs() |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 107 | self.assertEqual(baz.__doc__, "Whee!") |
| 108 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 109 | class ClosingTestCase(unittest.TestCase): |
| 110 | |
| 111 | # XXX This needs more work |
| 112 | |
| 113 | def test_closing(self): |
| 114 | state = [] |
| 115 | class C: |
| 116 | def close(self): |
| 117 | state.append(1) |
| 118 | x = C() |
| 119 | self.assertEqual(state, []) |
| 120 | with closing(x) as y: |
| 121 | self.assertEqual(x, y) |
| 122 | self.assertEqual(state, [1]) |
| 123 | |
| 124 | def test_closing_error(self): |
| 125 | state = [] |
| 126 | class C: |
| 127 | def close(self): |
| 128 | state.append(1) |
| 129 | x = C() |
| 130 | self.assertEqual(state, []) |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 131 | with self.assertRaises(ZeroDivisionError): |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 132 | with closing(x) as y: |
| 133 | self.assertEqual(x, y) |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 134 | 1 / 0 |
| 135 | self.assertEqual(state, [1]) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 136 | |
| 137 | class FileContextTestCase(unittest.TestCase): |
| 138 | |
| 139 | def testWithOpen(self): |
| 140 | tfn = tempfile.mktemp() |
| 141 | try: |
| 142 | f = None |
| 143 | with open(tfn, "w") as f: |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 144 | self.assertFalse(f.closed) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 145 | f.write("Booh\n") |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 146 | self.assertTrue(f.closed) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 147 | f = None |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 148 | with self.assertRaises(ZeroDivisionError): |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 149 | with open(tfn, "r") as f: |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 150 | self.assertFalse(f.closed) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 151 | self.assertEqual(f.read(), "Booh\n") |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 152 | 1 / 0 |
| 153 | self.assertTrue(f.closed) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 154 | finally: |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 155 | support.unlink(tfn) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 156 | |
Victor Stinner | 45df820 | 2010-04-28 22:31:17 +0000 | [diff] [blame] | 157 | @unittest.skipUnless(threading, 'Threading required for this test.') |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 158 | class LockContextTestCase(unittest.TestCase): |
| 159 | |
| 160 | def boilerPlate(self, lock, locked): |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 161 | self.assertFalse(locked()) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 162 | with lock: |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 163 | self.assertTrue(locked()) |
| 164 | self.assertFalse(locked()) |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 165 | with self.assertRaises(ZeroDivisionError): |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 166 | with lock: |
Benjamin Peterson | c9c0f20 | 2009-06-30 23:06:06 +0000 | [diff] [blame] | 167 | self.assertTrue(locked()) |
Florent Xicluna | 41fe615 | 2010-04-02 18:52:12 +0000 | [diff] [blame] | 168 | 1 / 0 |
| 169 | self.assertFalse(locked()) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 170 | |
| 171 | def testWithLock(self): |
| 172 | lock = threading.Lock() |
| 173 | self.boilerPlate(lock, lock.locked) |
| 174 | |
| 175 | def testWithRLock(self): |
| 176 | lock = threading.RLock() |
| 177 | self.boilerPlate(lock, lock._is_owned) |
| 178 | |
| 179 | def testWithCondition(self): |
| 180 | lock = threading.Condition() |
| 181 | def locked(): |
| 182 | return lock._is_owned() |
| 183 | self.boilerPlate(lock, locked) |
| 184 | |
| 185 | def testWithSemaphore(self): |
| 186 | lock = threading.Semaphore() |
| 187 | def locked(): |
| 188 | if lock.acquire(False): |
| 189 | lock.release() |
| 190 | return False |
| 191 | else: |
| 192 | return True |
| 193 | self.boilerPlate(lock, locked) |
| 194 | |
| 195 | def testWithBoundedSemaphore(self): |
| 196 | lock = threading.BoundedSemaphore() |
| 197 | def locked(): |
| 198 | if lock.acquire(False): |
| 199 | lock.release() |
| 200 | return False |
| 201 | else: |
| 202 | return True |
| 203 | self.boilerPlate(lock, locked) |
| 204 | |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 205 | |
| 206 | class mycontext(ContextDecorator): |
| 207 | started = False |
| 208 | exc = None |
| 209 | catch = False |
| 210 | |
| 211 | def __enter__(self): |
| 212 | self.started = True |
| 213 | return self |
| 214 | |
| 215 | def __exit__(self, *exc): |
| 216 | self.exc = exc |
| 217 | return self.catch |
| 218 | |
| 219 | |
| 220 | class TestContextDecorator(unittest.TestCase): |
| 221 | |
| 222 | def test_contextdecorator(self): |
| 223 | context = mycontext() |
| 224 | with context as result: |
| 225 | self.assertIs(result, context) |
| 226 | self.assertTrue(context.started) |
| 227 | |
| 228 | self.assertEqual(context.exc, (None, None, None)) |
| 229 | |
| 230 | |
| 231 | def test_contextdecorator_with_exception(self): |
| 232 | context = mycontext() |
| 233 | |
Ezio Melotti | ed3a7d2 | 2010-12-01 02:32:32 +0000 | [diff] [blame] | 234 | with self.assertRaisesRegex(NameError, 'foo'): |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 235 | with context: |
| 236 | raise NameError('foo') |
| 237 | self.assertIsNotNone(context.exc) |
| 238 | self.assertIs(context.exc[0], NameError) |
| 239 | |
| 240 | context = mycontext() |
| 241 | context.catch = True |
| 242 | with context: |
| 243 | raise NameError('foo') |
| 244 | self.assertIsNotNone(context.exc) |
| 245 | self.assertIs(context.exc[0], NameError) |
| 246 | |
| 247 | |
| 248 | def test_decorator(self): |
| 249 | context = mycontext() |
| 250 | |
| 251 | @context |
| 252 | def test(): |
| 253 | self.assertIsNone(context.exc) |
| 254 | self.assertTrue(context.started) |
| 255 | test() |
| 256 | self.assertEqual(context.exc, (None, None, None)) |
| 257 | |
| 258 | |
| 259 | def test_decorator_with_exception(self): |
| 260 | context = mycontext() |
| 261 | |
| 262 | @context |
| 263 | def test(): |
| 264 | self.assertIsNone(context.exc) |
| 265 | self.assertTrue(context.started) |
| 266 | raise NameError('foo') |
| 267 | |
Ezio Melotti | ed3a7d2 | 2010-12-01 02:32:32 +0000 | [diff] [blame] | 268 | with self.assertRaisesRegex(NameError, 'foo'): |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 269 | test() |
| 270 | self.assertIsNotNone(context.exc) |
| 271 | self.assertIs(context.exc[0], NameError) |
| 272 | |
| 273 | |
| 274 | def test_decorating_method(self): |
| 275 | context = mycontext() |
| 276 | |
| 277 | class Test(object): |
| 278 | |
| 279 | @context |
| 280 | def method(self, a, b, c=None): |
| 281 | self.a = a |
| 282 | self.b = b |
| 283 | self.c = c |
| 284 | |
| 285 | # these tests are for argument passing when used as a decorator |
| 286 | test = Test() |
| 287 | test.method(1, 2) |
| 288 | self.assertEqual(test.a, 1) |
| 289 | self.assertEqual(test.b, 2) |
| 290 | self.assertEqual(test.c, None) |
| 291 | |
| 292 | test = Test() |
| 293 | test.method('a', 'b', 'c') |
| 294 | self.assertEqual(test.a, 'a') |
| 295 | self.assertEqual(test.b, 'b') |
| 296 | self.assertEqual(test.c, 'c') |
| 297 | |
| 298 | test = Test() |
| 299 | test.method(a=1, b=2) |
| 300 | self.assertEqual(test.a, 1) |
| 301 | self.assertEqual(test.b, 2) |
| 302 | |
| 303 | |
| 304 | def test_typo_enter(self): |
| 305 | class mycontext(ContextDecorator): |
| 306 | def __unter__(self): |
| 307 | pass |
| 308 | def __exit__(self, *exc): |
| 309 | pass |
| 310 | |
| 311 | with self.assertRaises(AttributeError): |
| 312 | with mycontext(): |
| 313 | pass |
| 314 | |
| 315 | |
| 316 | def test_typo_exit(self): |
| 317 | class mycontext(ContextDecorator): |
| 318 | def __enter__(self): |
| 319 | pass |
| 320 | def __uxit__(self, *exc): |
| 321 | pass |
| 322 | |
| 323 | with self.assertRaises(AttributeError): |
| 324 | with mycontext(): |
| 325 | pass |
| 326 | |
| 327 | |
| 328 | def test_contextdecorator_as_mixin(self): |
| 329 | class somecontext(object): |
| 330 | started = False |
| 331 | exc = None |
| 332 | |
| 333 | def __enter__(self): |
| 334 | self.started = True |
| 335 | return self |
| 336 | |
| 337 | def __exit__(self, *exc): |
| 338 | self.exc = exc |
| 339 | |
| 340 | class mycontext(somecontext, ContextDecorator): |
| 341 | pass |
| 342 | |
| 343 | context = mycontext() |
| 344 | @context |
| 345 | def test(): |
| 346 | self.assertIsNone(context.exc) |
| 347 | self.assertTrue(context.started) |
| 348 | test() |
| 349 | self.assertEqual(context.exc, (None, None, None)) |
| 350 | |
| 351 | |
| 352 | def test_contextmanager_as_decorator(self): |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 353 | @contextmanager |
| 354 | def woohoo(y): |
| 355 | state.append(y) |
| 356 | yield |
| 357 | state.append(999) |
| 358 | |
Nick Coghlan | 0ded3e3 | 2011-05-05 23:49:25 +1000 | [diff] [blame] | 359 | state = [] |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 360 | @woohoo(1) |
| 361 | def test(x): |
| 362 | self.assertEqual(state, [1]) |
| 363 | state.append(x) |
| 364 | test('something') |
| 365 | self.assertEqual(state, [1, 'something', 999]) |
| 366 | |
Nick Coghlan | 0ded3e3 | 2011-05-05 23:49:25 +1000 | [diff] [blame] | 367 | # Issue #11647: Ensure the decorated function is 'reusable' |
| 368 | state = [] |
| 369 | test('something else') |
| 370 | self.assertEqual(state, [1, 'something else', 999]) |
| 371 | |
Michael Foord | b3a8984 | 2010-06-30 12:17:50 +0000 | [diff] [blame] | 372 | |
Nick Coghlan | 3267a30 | 2012-05-21 22:54:43 +1000 | [diff] [blame] | 373 | class TestExitStack(unittest.TestCase): |
| 374 | |
| 375 | def test_no_resources(self): |
| 376 | with ExitStack(): |
| 377 | pass |
| 378 | |
| 379 | def test_callback(self): |
| 380 | expected = [ |
| 381 | ((), {}), |
| 382 | ((1,), {}), |
| 383 | ((1,2), {}), |
| 384 | ((), dict(example=1)), |
| 385 | ((1,), dict(example=1)), |
| 386 | ((1,2), dict(example=1)), |
| 387 | ] |
| 388 | result = [] |
| 389 | def _exit(*args, **kwds): |
| 390 | """Test metadata propagation""" |
| 391 | result.append((args, kwds)) |
| 392 | with ExitStack() as stack: |
| 393 | for args, kwds in reversed(expected): |
| 394 | if args and kwds: |
| 395 | f = stack.callback(_exit, *args, **kwds) |
| 396 | elif args: |
| 397 | f = stack.callback(_exit, *args) |
| 398 | elif kwds: |
| 399 | f = stack.callback(_exit, **kwds) |
| 400 | else: |
| 401 | f = stack.callback(_exit) |
| 402 | self.assertIs(f, _exit) |
| 403 | for wrapper in stack._exit_callbacks: |
| 404 | self.assertIs(wrapper.__wrapped__, _exit) |
| 405 | self.assertNotEqual(wrapper.__name__, _exit.__name__) |
| 406 | self.assertIsNone(wrapper.__doc__, _exit.__doc__) |
| 407 | self.assertEqual(result, expected) |
| 408 | |
| 409 | def test_push(self): |
| 410 | exc_raised = ZeroDivisionError |
| 411 | def _expect_exc(exc_type, exc, exc_tb): |
| 412 | self.assertIs(exc_type, exc_raised) |
| 413 | def _suppress_exc(*exc_details): |
| 414 | return True |
| 415 | def _expect_ok(exc_type, exc, exc_tb): |
| 416 | self.assertIsNone(exc_type) |
| 417 | self.assertIsNone(exc) |
| 418 | self.assertIsNone(exc_tb) |
| 419 | class ExitCM(object): |
| 420 | def __init__(self, check_exc): |
| 421 | self.check_exc = check_exc |
| 422 | def __enter__(self): |
| 423 | self.fail("Should not be called!") |
| 424 | def __exit__(self, *exc_details): |
| 425 | self.check_exc(*exc_details) |
| 426 | with ExitStack() as stack: |
| 427 | stack.push(_expect_ok) |
| 428 | self.assertIs(stack._exit_callbacks[-1], _expect_ok) |
| 429 | cm = ExitCM(_expect_ok) |
| 430 | stack.push(cm) |
| 431 | self.assertIs(stack._exit_callbacks[-1].__self__, cm) |
| 432 | stack.push(_suppress_exc) |
| 433 | self.assertIs(stack._exit_callbacks[-1], _suppress_exc) |
| 434 | cm = ExitCM(_expect_exc) |
| 435 | stack.push(cm) |
| 436 | self.assertIs(stack._exit_callbacks[-1].__self__, cm) |
| 437 | stack.push(_expect_exc) |
| 438 | self.assertIs(stack._exit_callbacks[-1], _expect_exc) |
| 439 | stack.push(_expect_exc) |
| 440 | self.assertIs(stack._exit_callbacks[-1], _expect_exc) |
| 441 | 1/0 |
| 442 | |
| 443 | def test_enter_context(self): |
| 444 | class TestCM(object): |
| 445 | def __enter__(self): |
| 446 | result.append(1) |
| 447 | def __exit__(self, *exc_details): |
| 448 | result.append(3) |
| 449 | |
| 450 | result = [] |
| 451 | cm = TestCM() |
| 452 | with ExitStack() as stack: |
| 453 | @stack.callback # Registered first => cleaned up last |
| 454 | def _exit(): |
| 455 | result.append(4) |
| 456 | self.assertIsNotNone(_exit) |
| 457 | stack.enter_context(cm) |
| 458 | self.assertIs(stack._exit_callbacks[-1].__self__, cm) |
| 459 | result.append(2) |
| 460 | self.assertEqual(result, [1, 2, 3, 4]) |
| 461 | |
| 462 | def test_close(self): |
| 463 | result = [] |
| 464 | with ExitStack() as stack: |
| 465 | @stack.callback |
| 466 | def _exit(): |
| 467 | result.append(1) |
| 468 | self.assertIsNotNone(_exit) |
| 469 | stack.close() |
| 470 | result.append(2) |
| 471 | self.assertEqual(result, [1, 2]) |
| 472 | |
| 473 | def test_pop_all(self): |
| 474 | result = [] |
| 475 | with ExitStack() as stack: |
| 476 | @stack.callback |
| 477 | def _exit(): |
| 478 | result.append(3) |
| 479 | self.assertIsNotNone(_exit) |
| 480 | new_stack = stack.pop_all() |
| 481 | result.append(1) |
| 482 | result.append(2) |
| 483 | new_stack.close() |
| 484 | self.assertEqual(result, [1, 2, 3]) |
| 485 | |
Nick Coghlan | c73e8c2 | 2012-05-31 23:49:26 +1000 | [diff] [blame] | 486 | def test_exit_raise(self): |
| 487 | with self.assertRaises(ZeroDivisionError): |
| 488 | with ExitStack() as stack: |
| 489 | stack.push(lambda *exc: False) |
| 490 | 1/0 |
| 491 | |
| 492 | def test_exit_suppress(self): |
| 493 | with ExitStack() as stack: |
| 494 | stack.push(lambda *exc: True) |
| 495 | 1/0 |
| 496 | |
| 497 | def test_exit_exception_chaining_reference(self): |
| 498 | # Sanity check to make sure that ExitStack chaining matches |
| 499 | # actual nested with statements |
| 500 | class RaiseExc: |
| 501 | def __init__(self, exc): |
| 502 | self.exc = exc |
| 503 | def __enter__(self): |
| 504 | return self |
| 505 | def __exit__(self, *exc_details): |
| 506 | raise self.exc |
| 507 | |
Nick Coghlan | 77452fc | 2012-06-01 22:48:32 +1000 | [diff] [blame] | 508 | class RaiseExcWithContext: |
| 509 | def __init__(self, outer, inner): |
| 510 | self.outer = outer |
| 511 | self.inner = inner |
| 512 | def __enter__(self): |
| 513 | return self |
| 514 | def __exit__(self, *exc_details): |
| 515 | try: |
| 516 | raise self.inner |
| 517 | except: |
| 518 | raise self.outer |
| 519 | |
Nick Coghlan | c73e8c2 | 2012-05-31 23:49:26 +1000 | [diff] [blame] | 520 | class SuppressExc: |
| 521 | def __enter__(self): |
| 522 | return self |
| 523 | def __exit__(self, *exc_details): |
| 524 | type(self).saved_details = exc_details |
| 525 | return True |
| 526 | |
| 527 | try: |
| 528 | with RaiseExc(IndexError): |
Nick Coghlan | 77452fc | 2012-06-01 22:48:32 +1000 | [diff] [blame] | 529 | with RaiseExcWithContext(KeyError, AttributeError): |
| 530 | with SuppressExc(): |
| 531 | with RaiseExc(ValueError): |
| 532 | 1 / 0 |
Nick Coghlan | c73e8c2 | 2012-05-31 23:49:26 +1000 | [diff] [blame] | 533 | except IndexError as exc: |
| 534 | self.assertIsInstance(exc.__context__, KeyError) |
| 535 | self.assertIsInstance(exc.__context__.__context__, AttributeError) |
| 536 | # Inner exceptions were suppressed |
| 537 | self.assertIsNone(exc.__context__.__context__.__context__) |
| 538 | else: |
| 539 | self.fail("Expected IndexError, but no exception was raised") |
| 540 | # Check the inner exceptions |
| 541 | inner_exc = SuppressExc.saved_details[1] |
| 542 | self.assertIsInstance(inner_exc, ValueError) |
| 543 | self.assertIsInstance(inner_exc.__context__, ZeroDivisionError) |
| 544 | |
| 545 | def test_exit_exception_chaining(self): |
| 546 | # Ensure exception chaining matches the reference behaviour |
| 547 | def raise_exc(exc): |
| 548 | raise exc |
| 549 | |
| 550 | saved_details = None |
| 551 | def suppress_exc(*exc_details): |
| 552 | nonlocal saved_details |
| 553 | saved_details = exc_details |
| 554 | return True |
| 555 | |
| 556 | try: |
| 557 | with ExitStack() as stack: |
| 558 | stack.callback(raise_exc, IndexError) |
| 559 | stack.callback(raise_exc, KeyError) |
| 560 | stack.callback(raise_exc, AttributeError) |
| 561 | stack.push(suppress_exc) |
| 562 | stack.callback(raise_exc, ValueError) |
| 563 | 1 / 0 |
| 564 | except IndexError as exc: |
| 565 | self.assertIsInstance(exc.__context__, KeyError) |
| 566 | self.assertIsInstance(exc.__context__.__context__, AttributeError) |
Nick Coghlan | 77452fc | 2012-06-01 22:48:32 +1000 | [diff] [blame] | 567 | # Inner exceptions were suppressed |
| 568 | self.assertIsNone(exc.__context__.__context__.__context__) |
Nick Coghlan | c73e8c2 | 2012-05-31 23:49:26 +1000 | [diff] [blame] | 569 | else: |
| 570 | self.fail("Expected IndexError, but no exception was raised") |
| 571 | # Check the inner exceptions |
| 572 | inner_exc = saved_details[1] |
| 573 | self.assertIsInstance(inner_exc, ValueError) |
| 574 | self.assertIsInstance(inner_exc.__context__, ZeroDivisionError) |
| 575 | |
Nick Coghlan | 1a33b2f | 2013-10-01 23:24:56 +1000 | [diff] [blame] | 576 | def test_exit_exception_non_suppressing(self): |
| 577 | # http://bugs.python.org/issue19092 |
| 578 | def raise_exc(exc): |
| 579 | raise exc |
| 580 | |
| 581 | def suppress_exc(*exc_details): |
| 582 | return True |
| 583 | |
| 584 | try: |
| 585 | with ExitStack() as stack: |
| 586 | stack.callback(lambda: None) |
| 587 | stack.callback(raise_exc, IndexError) |
| 588 | except Exception as exc: |
| 589 | self.assertIsInstance(exc, IndexError) |
| 590 | else: |
| 591 | self.fail("Expected IndexError, but no exception was raised") |
| 592 | |
| 593 | try: |
| 594 | with ExitStack() as stack: |
| 595 | stack.callback(raise_exc, KeyError) |
| 596 | stack.push(suppress_exc) |
| 597 | stack.callback(raise_exc, IndexError) |
| 598 | except Exception as exc: |
| 599 | self.assertIsInstance(exc, KeyError) |
| 600 | else: |
| 601 | self.fail("Expected KeyError, but no exception was raised") |
| 602 | |
| 603 | def test_body_exception_suppress(self): |
| 604 | def suppress_exc(*exc_details): |
| 605 | return True |
| 606 | try: |
| 607 | with ExitStack() as stack: |
| 608 | stack.push(suppress_exc) |
| 609 | 1/0 |
| 610 | except IndexError as exc: |
| 611 | self.fail("Expected no exception, got IndexError") |
| 612 | |
Nick Coghlan | c73e8c2 | 2012-05-31 23:49:26 +1000 | [diff] [blame] | 613 | def test_exit_exception_chaining_suppress(self): |
| 614 | with ExitStack() as stack: |
| 615 | stack.push(lambda *exc: True) |
| 616 | stack.push(lambda *exc: 1/0) |
| 617 | stack.push(lambda *exc: {}[1]) |
| 618 | |
Nick Coghlan | a5bd2a1 | 2012-06-01 00:00:38 +1000 | [diff] [blame] | 619 | def test_excessive_nesting(self): |
| 620 | # The original implementation would die with RecursionError here |
| 621 | with ExitStack() as stack: |
| 622 | for i in range(10000): |
| 623 | stack.callback(int) |
| 624 | |
Nick Coghlan | 3267a30 | 2012-05-21 22:54:43 +1000 | [diff] [blame] | 625 | def test_instance_bypass(self): |
| 626 | class Example(object): pass |
| 627 | cm = Example() |
| 628 | cm.__exit__ = object() |
| 629 | stack = ExitStack() |
| 630 | self.assertRaises(AttributeError, stack.enter_context, cm) |
| 631 | stack.push(cm) |
| 632 | self.assertIs(stack._exit_callbacks[-1], cm) |
| 633 | |
| 634 | |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 635 | # This is needed to make the test actually run under regrtest.py! |
| 636 | def test_main(): |
Benjamin Peterson | c8c0d78 | 2009-07-01 01:39:51 +0000 | [diff] [blame] | 637 | support.run_unittest(__name__) |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 638 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 639 | if __name__ == "__main__": |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 640 | test_main() |