Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/hypothesis/errors.py: 68%
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1# This file is part of Hypothesis, which may be found at
2# https://github.com/HypothesisWorks/hypothesis/
3#
4# Copyright the Hypothesis Authors.
5# Individual contributors are listed in AUTHORS.rst and the git log.
6#
7# This Source Code Form is subject to the terms of the Mozilla Public License,
8# v. 2.0. If a copy of the MPL was not distributed with this file, You can
9# obtain one at https://mozilla.org/MPL/2.0/.
11from datetime import timedelta
12from typing import Any, Literal, Optional
14from hypothesis.internal.compat import ExceptionGroup
17class HypothesisException(Exception):
18 """Generic parent class for exceptions thrown by Hypothesis."""
21class _Trimmable(HypothesisException):
22 """Hypothesis can trim these tracebacks even if they're raised internally."""
25class UnsatisfiedAssumption(HypothesisException):
26 """An internal error raised by assume.
28 If you're seeing this error something has gone wrong.
29 """
31 def __init__(self, reason: Optional[str] = None) -> None:
32 self.reason = reason
35class NoSuchExample(HypothesisException):
36 """The condition we have been asked to satisfy appears to be always false.
38 This does not guarantee that no example exists, only that we were
39 unable to find one.
40 """
42 def __init__(self, condition_string: str, extra: str = "") -> None:
43 super().__init__(f"No examples found of condition {condition_string}{extra}")
46class Unsatisfiable(_Trimmable):
47 """We ran out of time or examples before we could find enough examples
48 which satisfy the assumptions of this hypothesis.
50 This could be because the function is too slow. If so, try upping
51 the timeout. It could also be because the function is using assume
52 in a way that is too hard to satisfy. If so, try writing a custom
53 strategy or using a better starting point (e.g if you are requiring
54 a list has unique values you could instead filter out all duplicate
55 values from the list)
56 """
59class ChoiceTooLarge(HypothesisException):
60 """An internal error raised by choice_from_index."""
63class Flaky(_Trimmable):
64 """Base class for indeterministic failures. Usually one of the more
65 specific subclasses (FlakyFailure or FlakyStrategyDefinition) is raised."""
68class FlakyReplay(Flaky):
69 """Internal error raised by the conjecture engine if flaky failures are
70 detected during replay.
72 Carries information allowing the runner to reconstruct the flakiness as
73 a FlakyFailure exception group for final presentation.
74 """
76 def __init__(self, reason, interesting_origins=None):
77 super().__init__(reason)
78 self.reason = reason
79 self._interesting_origins = interesting_origins
82class FlakyStrategyDefinition(Flaky):
83 """This function appears to cause inconsistent data generation.
85 Common causes for this problem are:
86 1. The strategy depends on external state. e.g. it uses an external
87 random number generator. Try to make a version that passes all the
88 relevant state in from Hypothesis.
89 """
92class _WrappedBaseException(Exception):
93 """Used internally for wrapping BaseExceptions as components of FlakyFailure."""
96class FlakyFailure(ExceptionGroup, Flaky):
97 """This function appears to fail non-deterministically: We have seen it
98 fail when passed this example at least once, but a subsequent invocation
99 did not fail, or caused a distinct error.
101 Common causes for this problem are:
102 1. The function depends on external state. e.g. it uses an external
103 random number generator. Try to make a version that passes all the
104 relevant state in from Hypothesis.
105 2. The function is suffering from too much recursion and its failure
106 depends sensitively on where it's been called from.
107 3. The function is timing sensitive and can fail or pass depending on
108 how long it takes. Try breaking it up into smaller functions which
109 don't do that and testing those instead.
110 """
112 def __new__(cls, msg, group):
113 # The Exception mixin forces this an ExceptionGroup (only accepting
114 # Exceptions, not BaseException). Usually BaseException is raised
115 # directly and will hence not be part of a FlakyFailure, but I'm not
116 # sure this assumption holds everywhere. So wrap any BaseExceptions.
117 group = list(group)
118 for i, exc in enumerate(group):
119 if not isinstance(exc, Exception):
120 err = _WrappedBaseException()
121 err.__cause__ = err.__context__ = exc
122 group[i] = err
123 return ExceptionGroup.__new__(cls, msg, group)
125 # defining `derive` is required for `split` to return an instance of FlakyFailure
126 # instead of ExceptionGroup. See https://github.com/python/cpython/issues/119287
127 # and https://docs.python.org/3/library/exceptions.html#BaseExceptionGroup.derive
128 def derive(self, excs):
129 return type(self)(self.message, excs)
132class FlakyBackendFailure(FlakyFailure):
133 """
134 A failure was reported by an :ref:`alternative backend <alternative-backends>`,
135 but this failure did not reproduce when replayed under the Hypothesis backend.
137 When an alternative backend reports a failure, Hypothesis first replays it
138 under the standard Hypothesis backend to check for flakiness. If the failure
139 does not reproduce, Hypothesis raises this exception.
140 """
143class InvalidArgument(_Trimmable, TypeError):
144 """Used to indicate that the arguments to a Hypothesis function were in
145 some manner incorrect."""
148class ResolutionFailed(InvalidArgument):
149 """Hypothesis had to resolve a type to a strategy, but this failed.
151 Type inference is best-effort, so this only happens when an
152 annotation exists but could not be resolved for a required argument
153 to the target of ``builds()``, or where the user passed ``...``.
154 """
157class InvalidState(HypothesisException):
158 """The system is not in a state where you were allowed to do that."""
161class InvalidDefinition(_Trimmable, TypeError):
162 """Used to indicate that a class definition was not well put together and
163 has something wrong with it."""
166class HypothesisWarning(HypothesisException, Warning):
167 """A generic warning issued by Hypothesis."""
170class FailedHealthCheck(_Trimmable):
171 """Raised when a test fails a healthcheck."""
174class NonInteractiveExampleWarning(HypothesisWarning):
175 """SearchStrategy.example() is designed for interactive use,
176 but should never be used in the body of a test.
177 """
180class HypothesisDeprecationWarning(HypothesisWarning, FutureWarning):
181 """A deprecation warning issued by Hypothesis.
183 Actually inherits from FutureWarning, because DeprecationWarning is
184 hidden by the default warnings filter.
186 You can configure the Python :mod:`python:warnings` to handle these
187 warnings differently to others, either turning them into errors or
188 suppressing them entirely. Obviously we would prefer the former!
189 """
192class HypothesisSideeffectWarning(HypothesisWarning):
193 """A warning issued by Hypothesis when it sees actions that are
194 discouraged at import or initialization time because they are
195 slow or have user-visible side effects.
196 """
199class Frozen(HypothesisException):
200 """Raised when a mutation method has been called on a ConjectureData object
201 after freeze() has been called."""
204def __getattr__(name: str) -> Any:
205 if name == "MultipleFailures":
206 from hypothesis._settings import note_deprecation
207 from hypothesis.internal.compat import BaseExceptionGroup
209 note_deprecation(
210 "MultipleFailures is deprecated; use the builtin `BaseExceptionGroup` type "
211 "instead, or `exceptiongroup.BaseExceptionGroup` before Python 3.11",
212 since="2022-08-02",
213 has_codemod=False, # This would be a great PR though!
214 stacklevel=1,
215 )
216 return BaseExceptionGroup
218 raise AttributeError(f"Module 'hypothesis.errors' has no attribute {name}")
221class DeadlineExceeded(_Trimmable):
222 """
223 Raised when an input takes too long to run, relative to the |settings.deadline|
224 setting.
225 """
227 def __init__(self, runtime: timedelta, deadline: timedelta) -> None:
228 super().__init__(
229 f"Test took {runtime.total_seconds() * 1000:.2f}ms, which exceeds "
230 f"the deadline of {deadline.total_seconds() * 1000:.2f}ms"
231 )
232 self.runtime = runtime
233 self.deadline = deadline
235 def __reduce__(
236 self,
237 ) -> tuple[type["DeadlineExceeded"], tuple[timedelta, timedelta]]:
238 return (type(self), (self.runtime, self.deadline))
241class StopTest(BaseException):
242 """Raised when a test should stop running and return control to
243 the Hypothesis engine, which should then continue normally.
244 """
246 def __init__(self, testcounter: int) -> None:
247 super().__init__(repr(testcounter))
248 self.testcounter = testcounter
251class DidNotReproduce(HypothesisException):
252 pass
255class Found(HypothesisException):
256 """Signal that the example matches condition. Internal use only."""
259class RewindRecursive(Exception):
260 """Signal that the type inference should be rewound due to recursive types. Internal use only."""
262 def __init__(self, target: object) -> None:
263 self.target = target
266class SmallSearchSpaceWarning(HypothesisWarning):
267 """Indicates that an inferred strategy does not span the search space
268 in a meaningful way, for example by only creating default instances."""
271CannotProceedScopeT = Literal["verified", "exhausted", "discard_test_case", "other"]
274class BackendCannotProceed(HypothesisException):
275 """
276 Raised by alternative backends when a |PrimitiveProvider| cannot proceed.
277 This is expected to occur inside one of the ``.draw_*()`` methods, or for
278 symbolic execution perhaps in |PrimitiveProvider.realize|.
280 The optional ``scope`` argument can enable smarter integration:
282 verified:
283 Do not request further test cases from this backend. We *may*
284 generate more test cases with other backends; if one fails then
285 Hypothesis will report unsound verification in the backend too.
287 exhausted:
288 Do not request further test cases from this backend; finish testing
289 with test cases generated with the default backend. Common if e.g.
290 native code blocks symbolic reasoning very early.
292 discard_test_case:
293 This particular test case could not be converted to concrete values;
294 skip any further processing and continue with another test case from
295 this backend.
296 """
298 def __init__(self, scope: CannotProceedScopeT = "other", /) -> None:
299 self.scope = scope