def evaluate_test_data(self, data):
try:
result = self.execute(data)
if result is not None:
fail_health_check(
self.settings,
('Tests run under @given should return None, but '
'%s returned %r instead.') % (self.test.__name__, result),
HealthCheck.return_value)
except UnsatisfiedAssumption:
data.mark_invalid()
except (
HypothesisDeprecationWarning,
FailedHealthCheck,
StopTest,
) + EXCEPTIONS_TO_RERAISE:
raise
except EXCEPTIONS_TO_FAIL as e:
escalate_hypothesis_internal_error()
tb = get_trimmed_traceback()
data.__expected_traceback = ''.join(
traceback.format_exception(type(e), e, tb))
data.__expected_exception = e
verbose_report(data.__expected_traceback)
origin = traceback.extract_tb(tb)[-1]
filename = origin[0]
lineno = origin[1]
data.mark_interesting((type(e), filename, lineno))
def _execute_once_for_engine(self, data):
"""Wrapper around ``execute_once`` that intercepts test failure
exceptions and single-test control exceptions, and turns them into
appropriate method calls to `data` instead.
This allows the engine to assume that any exception other than
``StopTest`` must be a fatal error, and should stop the entire engine.
"""
try:
result = self.execute_once(data)
if result is not None:
fail_health_check(
self.settings,
("Tests run under @given should return None, but "
"%s returned %r instead.") % (self.test.__name__, result),
HealthCheck.return_value,
)
except UnsatisfiedAssumption:
# An "assume" check failed, so instead we inform the engine that
# this test run was invalid.
data.mark_invalid()
except StopTest:
# The engine knows how to handle this control exception, so it's
# OK to re-raise it.
raise
except (
HypothesisDeprecationWarning,
FailedHealthCheck,
) + skip_exceptions_to_reraise():
# These are fatal errors or control exceptions that should stop the
# engine, so we re-raise them.
raise
except failure_exceptions_to_catch() as e:
# If the error was raised by Hypothesis-internal code, re-raise it
# as a fatal error instead of treating it as a test failure.
escalate_hypothesis_internal_error()
if data.frozen:
# This can happen if an error occurred in a finally
# block somewhere, suppressing our original StopTest.
# We raise a new one here to resume normal operation.
raise StopTest(data.testcounter)
else:
# The test failed by raising an exception, so we inform the
# engine that this test run was interesting. This is the normal
# path for test runs that fail.
tb = get_trimmed_traceback()
info = data.extra_information
info.__expected_traceback = "".join(
traceback.format_exception(type(e), e, tb))
info.__expected_exception = e
verbose_report(info.__expected_traceback)
origin = traceback.extract_tb(tb)[-1]
filename = origin[0]
lineno = origin[1]
data.mark_interesting((type(e), filename, lineno))
def evaluate_test_data(self, data):
try:
result = self.execute(data)
if result is not None:
fail_health_check(
self.settings,
(
"Tests run under @given should return None, but "
"%s returned %r instead."
)
% (self.test.__name__, result),
HealthCheck.return_value,
)
except UnsatisfiedAssumption:
data.mark_invalid()
except (
HypothesisDeprecationWarning,
FailedHealthCheck,
StopTest,
) + skip_exceptions_to_reraise():
raise
except failure_exceptions_to_catch() as e:
escalate_hypothesis_internal_error()
if data.frozen:
# This can happen if an error occurred in a finally
# block somewhere, suppressing our original StopTest.
# We raise a new one here to resume normal operation.
raise StopTest(data.testcounter)
else:
tb = get_trimmed_traceback()
info = data.extra_information
info.__expected_traceback = "".join(
traceback.format_exception(type(e), e, tb)
)
info.__expected_exception = e
verbose_report(info.__expected_traceback)
origin = traceback.extract_tb(tb)[-1]
filename = origin[0]
lineno = origin[1]
data.mark_interesting((type(e), filename, lineno))
def evaluate_test_data(self, data):
try:
result = self.execute(data)
if result is not None:
fail_health_check(
self.settings,
(
"Tests run under @given should return None, but "
"%s returned %r instead."
)
% (self.test.__name__, result),
HealthCheck.return_value,
)
except UnsatisfiedAssumption:
data.mark_invalid()
except (
HypothesisDeprecationWarning,
FailedHealthCheck,
StopTest,
) + skip_exceptions_to_reraise():
raise
except failure_exceptions_to_catch() as e:
escalate_hypothesis_internal_error()
if data.frozen:
# This can happen if an error occurred in a finally
# block somewhere, suppressing our original StopTest.
# We raise a new one here to resume normal operation.
raise StopTest(data.testcounter)
else:
tb = get_trimmed_traceback()
info = data.extra_information
info.__expected_traceback = "".join(
traceback.format_exception(type(e), e, tb)
)
info.__expected_exception = e
verbose_report(info.__expected_traceback)
origin = traceback.extract_tb(tb)[-1]
filename = origin[0]
lineno = origin[1]
data.mark_interesting((type(e), filename, lineno))
def wrapped_test(*arguments, **kwargs):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
test = wrapped_test.hypothesis.inner_test
if getattr(test, "is_hypothesis_test", False):
raise InvalidArgument((
"You have applied @given to the test %s more than once, which "
"wraps the test several times and is extremely slow. A "
"similar effect can be gained by combining the arguments "
"of the two calls to given. For example, instead of "
"@given(booleans()) @given(integers()), you could write "
"@given(booleans(), integers())") % (test.__name__, ))
settings = wrapped_test._hypothesis_internal_use_settings
random = get_random_for_wrapped_test(test, wrapped_test)
# Use type information to convert "infer" arguments into appropriate
# strategies.
if infer in given_kwargs.values():
hints = get_type_hints(test)
for name in [
name for name, value in given_kwargs.items()
if value is infer
]:
if name not in hints:
raise InvalidArgument(
"passed %s=infer for %s, but %s has no type annotation"
% (name, test.__name__, name))
given_kwargs[name] = st.from_type(hints[name])
processed_args = process_arguments_to_given(
wrapped_test,
arguments,
kwargs,
given_kwargs,
argspec,
test,
settings,
)
arguments, kwargs, test_runner, search_strategy = processed_args
runner = getattr(search_strategy, "runner", None)
if isinstance(runner, TestCase) and test.__name__ in dir(TestCase):
msg = ("You have applied @given to the method %s, which is "
"used by the unittest runner but is not itself a test."
" This is not useful in any way." % test.__name__)
fail_health_check(settings, msg, HealthCheck.not_a_test_method)
if bad_django_TestCase(runner): # pragma: no cover
# Covered by the Django tests, but not the pytest coverage task
raise InvalidArgument(
"You have applied @given to a method on %s, but this "
"class does not inherit from the supported versions in "
"`hypothesis.extra.django`. Use the Hypothesis variants "
"to ensure that each example is run in a separate "
"database transaction." % qualname(type(runner)))
state = StateForActualGivenExecution(
test_runner,
search_strategy,
test,
settings,
random,
wrapped_test,
)
reproduce_failure = wrapped_test._hypothesis_internal_use_reproduce_failure
# If there was a @reproduce_failure decorator, use it to reproduce
# the error (or complain that we couldn't). Either way, this will
# always raise some kind of error.
if reproduce_failure is not None:
expected_version, failure = reproduce_failure
if expected_version != __version__:
raise InvalidArgument(
("Attempting to reproduce a failure from a different "
"version of Hypothesis. This failure is from %s, but "
"you are currently running %r. Please change your "
"Hypothesis version to a matching one.") %
(expected_version, __version__))
try:
state.execute_once(
ConjectureData.for_buffer(decode_failure(failure)),
print_example=True,
is_final=True,
)
raise DidNotReproduce(
"Expected the test to raise an error, but it "
"completed successfully.")
except StopTest:
raise DidNotReproduce(
"The shape of the test data has changed in some way "
"from where this blob was defined. Are you sure "
"you're running the same test?")
except UnsatisfiedAssumption:
raise DidNotReproduce(
"The test data failed to satisfy an assumption in the "
"test. Have you added it since this blob was "
"generated?")
# There was no @reproduce_failure, so start by running any explicit
# examples from @example decorators.
execute_explicit_examples(state, wrapped_test, arguments, kwargs)
# If there were any explicit examples, they all ran successfully.
# The next step is to use the Conjecture engine to run the test on
# many different inputs.
if settings.max_examples <= 0:
return
if not (Phase.reuse in settings.phases
or Phase.generate in settings.phases):
return
try:
if isinstance(runner, TestCase) and hasattr(runner, "subTest"):
subTest = runner.subTest
try:
runner.subTest = fake_subTest
state.run_engine()
finally:
runner.subTest = subTest
else:
state.run_engine()
except BaseException as e:
# The exception caught here should either be an actual test
# failure (or MultipleFailures), or some kind of fatal error
# that caused the engine to stop.
generated_seed = wrapped_test._hypothesis_internal_use_generated_seed
with local_settings(settings):
if not (state.failed_normally or generated_seed is None):
if running_under_pytest:
report(
"You can add @seed(%(seed)d) to this test or "
"run pytest with --hypothesis-seed=%(seed)d "
"to reproduce this failure." %
{"seed": generated_seed})
else:
report("You can add @seed(%d) to this test to "
"reproduce this failure." %
(generated_seed, ))
# The dance here is to avoid showing users long tracebacks
# full of Hypothesis internals they don't care about.
# We have to do this inline, to avoid adding another
# internal stack frame just when we've removed the rest.
if PY2:
# Python 2 doesn't have Exception.with_traceback(...);
# instead it has a three-argument form of the `raise`
# statement. Unfortunately this is a SyntaxError on
# Python 3, and before Python 2.7.9 it was *also* a
# SyntaxError to use it in a nested function so we
# can't `exec` or `eval` our way out (BPO-21591).
# So unless we break some versions of Python 2, none
# of them get traceback elision.
raise
# On Python 3, we swap out the real traceback for our
# trimmed version. Using a variable ensures that the line
# which will actually appear in tracebacks is as clear as
# possible - "raise the_error_hypothesis_found".
the_error_hypothesis_found = e.with_traceback(
get_trimmed_traceback())
raise the_error_hypothesis_found
def run_engine(self):
"""Run the test function many times, on database input and generated
input, using the Conjecture engine.
"""
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
try:
database_key = self.wrapped_test._hypothesis_internal_database_key
except AttributeError:
if global_force_seed is None:
database_key = function_digest(self.test)
else:
database_key = None
runner = ConjectureRunner(
self._execute_once_for_engine,
settings=self.settings,
random=self.random,
database_key=database_key,
)
# Use the Conjecture engine to run the test function many times
# on different inputs.
runner.run()
note_engine_for_statistics(runner)
if runner.call_count == 0:
return
if runner.interesting_examples:
self.falsifying_examples = sorted(
runner.interesting_examples.values(),
key=lambda d: sort_key(d.buffer),
reverse=True,
)
else:
if runner.valid_examples == 0:
raise Unsatisfiable(
"Unable to satisfy assumptions of hypothesis %s." %
(get_pretty_function_description(self.test), ))
if not self.falsifying_examples:
return
elif not self.settings.report_multiple_bugs:
# Pretend that we only found one failure, by discarding the others.
del self.falsifying_examples[:-1]
# The engine found one or more failures, so we need to reproduce and
# report them.
self.failed_normally = True
flaky = 0
for falsifying_example in self.falsifying_examples:
info = falsifying_example.extra_information
ran_example = ConjectureData.for_buffer(falsifying_example.buffer)
self.__was_flaky = False
assert info.__expected_exception is not None
try:
self.execute_once(
ran_example,
print_example=not self.is_find,
is_final=True,
expected_failure=(
info.__expected_exception,
info.__expected_traceback,
),
)
except (UnsatisfiedAssumption, StopTest):
report(traceback.format_exc())
self.__flaky(
"Unreliable assumption: An example which satisfied "
"assumptions on the first run now fails it.")
except BaseException as e:
if len(self.falsifying_examples) <= 1:
# There is only one failure, so we can report it by raising
# it directly.
raise
# We are reporting multiple failures, so we need to manually
# print each exception's stack trace and information.
tb = get_trimmed_traceback()
report("".join(traceback.format_exception(type(e), e, tb)))
finally: # pragma: no cover
# Mostly useful for ``find`` and ensuring that objects that
# hold on to a reference to ``data`` know that it's now been
# finished and they shouldn't attempt to draw more data from
# it.
ran_example.freeze()
# This section is in fact entirely covered by the tests in
# test_reproduce_failure, but it seems to trigger a lovely set
# of coverage bugs: The branches show up as uncovered (despite
# definitely being covered - you can add an assert False else
# branch to verify this and see it fail - and additionally the
# second branch still complains about lack of coverage even if
# you add a pragma: no cover to it!
# See https://bitbucket.org/ned/coveragepy/issues/623/
if self.settings.print_blob:
report(("\nYou can reproduce this example by temporarily "
"adding @reproduce_failure(%r, %r) as a decorator "
"on your test case") %
(__version__,
encode_failure(falsifying_example.buffer)))
if self.__was_flaky:
flaky += 1
# If we only have one example then we should have raised an error or
# flaky prior to this point.
assert len(self.falsifying_examples) > 1
if flaky > 0:
raise Flaky(
("Hypothesis found %d distinct failures, but %d of them "
"exhibited some sort of flaky behaviour.") %
(len(self.falsifying_examples), flaky))
else:
raise MultipleFailures(("Hypothesis found %d distinct failures.") %
(len(self.falsifying_examples)))
def run(self):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
if global_force_seed is None:
database_key = function_digest(self.test)
else:
database_key = None
runner = ConjectureRunner(
self.evaluate_test_data,
settings=self.settings,
random=self.random,
database_key=database_key,
)
try:
runner.run()
finally:
self.used_examples_from_database = runner.used_examples_from_database
note_engine_for_statistics(runner)
self.used_examples_from_database = runner.used_examples_from_database
if runner.call_count == 0:
return
if runner.interesting_examples:
self.falsifying_examples = sorted(
[d for d in runner.interesting_examples.values()],
key=lambda d: sort_key(d.buffer),
reverse=True,
)
else:
if runner.valid_examples == 0:
raise Unsatisfiable(
"Unable to satisfy assumptions of hypothesis %s." %
(get_pretty_function_description(self.test), ))
if not self.falsifying_examples:
return
self.failed_normally = True
flaky = 0
for falsifying_example in self.falsifying_examples:
ran_example = ConjectureData.for_buffer(falsifying_example.buffer)
self.__was_flaky = False
assert falsifying_example.__expected_exception is not None
try:
self.execute(
ran_example,
print_example=True,
is_final=True,
expected_failure=(
falsifying_example.__expected_exception,
falsifying_example.__expected_traceback,
),
)
except (UnsatisfiedAssumption, StopTest):
report(traceback.format_exc())
self.__flaky(
"Unreliable assumption: An example which satisfied "
"assumptions on the first run now fails it.")
except BaseException as e:
if len(self.falsifying_examples) <= 1:
raise
tb = get_trimmed_traceback()
report("".join(traceback.format_exception(type(e), e, tb)))
finally: # pragma: no cover
# This section is in fact entirely covered by the tests in
# test_reproduce_failure, but it seems to trigger a lovely set
# of coverage bugs: The branches show up as uncovered (despite
# definitely being covered - you can add an assert False else
# branch to verify this and see it fail - and additionally the
# second branch still complains about lack of coverage even if
# you add a pragma: no cover to it!
# See https://bitbucket.org/ned/coveragepy/issues/623/
if self.settings.print_blob is not PrintSettings.NEVER:
failure_blob = encode_failure(falsifying_example.buffer)
# Have to use the example we actually ran, not the original
# falsifying example! Otherwise we won't catch problems
# where the repr of the generated example doesn't parse.
can_use_repr = ran_example.can_reproduce_example_from_repr
if self.settings.print_blob is PrintSettings.ALWAYS or (
self.settings.print_blob is PrintSettings.INFER
and self.settings.verbosity >= Verbosity.normal
and not can_use_repr and len(failure_blob) < 200):
report((
"\nYou can reproduce this example by temporarily "
"adding @reproduce_failure(%r, %r) as a decorator "
"on your test case") % (__version__, failure_blob))
if self.__was_flaky:
flaky += 1
# If we only have one example then we should have raised an error or
# flaky prior to this point.
assert len(self.falsifying_examples) > 1
if flaky > 0:
raise Flaky(
("Hypothesis found %d distinct failures, but %d of them "
"exhibited some sort of flaky behaviour.") %
(len(self.falsifying_examples), flaky))
else:
raise MultipleFailures(("Hypothesis found %d distinct failures.") %
(len(self.falsifying_examples)))
def wrapped_test(*arguments, **kwargs):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
test = wrapped_test.hypothesis.inner_test
if getattr(test, 'is_hypothesis_test', False):
note_deprecation(
('You have applied @given to test: %s more than once. In '
'future this will be an error. Applying @given twice '
'wraps the test twice, which can be extremely slow. A '
'similar effect can be gained by combining the arguments '
'of the two calls to given. For example, instead of '
'@given(booleans()) @given(integers()), you could write '
'@given(booleans(), integers())') % (test.__name__, ))
settings = wrapped_test._hypothesis_internal_use_settings
random = get_random_for_wrapped_test(test, wrapped_test)
if infer in generator_kwargs.values():
hints = get_type_hints(test)
for name in [
name for name, value in generator_kwargs.items()
if value is infer
]:
if name not in hints:
raise InvalidArgument(
'passed %s=infer for %s, but %s has no type annotation'
% (name, test.__name__, name))
generator_kwargs[name] = st.from_type(hints[name])
processed_args = process_arguments_to_given(
wrapped_test, arguments, kwargs, generator_arguments,
generator_kwargs, argspec, test, settings)
arguments, kwargs, test_runner, search_strategy = processed_args
runner = getattr(search_strategy, 'runner', None)
if isinstance(runner, TestCase) and test.__name__ in dir(TestCase):
msg = ('You have applied @given to the method %s, which is '
'used by the unittest runner but is not itself a test.'
' This is not useful in any way.' % test.__name__)
fail_health_check(settings, msg, HealthCheck.not_a_test_method)
if bad_django_TestCase(runner): # pragma: no cover
# Covered by the Django tests, but not the pytest coverage task
raise InvalidArgument(
'You have applied @given to a method on %s, but this '
'class does not inherit from the supported versions in '
'`hypothesis.extra.django`. Use the Hypothesis variants '
'to ensure that each example is run in a separate '
'database transaction.' % qualname(type(runner)))
state = StateForActualGivenExecution(
test_runner,
search_strategy,
test,
settings,
random,
had_seed=wrapped_test._hypothesis_internal_use_seed)
reproduce_failure = \
wrapped_test._hypothesis_internal_use_reproduce_failure
if reproduce_failure is not None:
expected_version, failure = reproduce_failure
if expected_version != __version__:
raise InvalidArgument(
('Attempting to reproduce a failure from a different '
'version of Hypothesis. This failure is from %s, but '
'you are currently running %r. Please change your '
'Hypothesis version to a matching one.') %
(expected_version, __version__))
try:
state.execute(
ConjectureData.for_buffer(decode_failure(failure)),
print_example=True,
is_final=True,
)
raise DidNotReproduce(
'Expected the test to raise an error, but it '
'completed successfully.')
except StopTest:
raise DidNotReproduce(
'The shape of the test data has changed in some way '
'from where this blob was defined. Are you sure '
"you're running the same test?")
except UnsatisfiedAssumption:
raise DidNotReproduce(
'The test data failed to satisfy an assumption in the '
'test. Have you added it since this blob was '
'generated?')
execute_explicit_examples(test_runner, test, wrapped_test,
settings, arguments, kwargs)
if settings.max_examples <= 0:
return
if not (Phase.reuse in settings.phases
or Phase.generate in settings.phases):
return
try:
if isinstance(runner, TestCase) and hasattr(runner, 'subTest'):
subTest = runner.subTest
try:
setattr(runner, 'subTest', fake_subTest)
state.run()
finally:
setattr(runner, 'subTest', subTest)
else:
state.run()
except BaseException as e:
generated_seed = \
wrapped_test._hypothesis_internal_use_generated_seed
with local_settings(settings):
if not (state.failed_normally or generated_seed is None):
if running_under_pytest:
report(
'You can add @seed(%(seed)d) to this test or '
'run pytest with --hypothesis-seed=%(seed)d '
'to reproduce this failure.' %
{'seed': generated_seed})
else:
report('You can add @seed(%d) to this test to '
'reproduce this failure.' %
(generated_seed, ))
# The dance here is to avoid showing users long tracebacks
# full of Hypothesis internals they don't care about.
# We have to do this inline, to avoid adding another
# internal stack frame just when we've removed the rest.
if PY2:
# Python 2 doesn't have Exception.with_traceback(...);
# instead it has a three-argument form of the `raise`
# statement. Unfortunately this is a SyntaxError on
# Python 3, and before Python 2.7.9 it was *also* a
# SyntaxError to use it in a nested function so we
# can't `exec` or `eval` our way out (BPO-21591).
# So unless we break some versions of Python 2, none
# of them get traceback elision.
raise
# On Python 3, we swap out the real traceback for our
# trimmed version. Using a variable ensures that the line
# which will actually appear in trackbacks is as clear as
# possible - "raise the_error_hypothesis_found".
the_error_hypothesis_found = \
e.with_traceback(get_trimmed_traceback())
raise the_error_hypothesis_found
def run(self):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
if global_force_seed is None:
database_key = str_to_bytes(fully_qualified_name(self.test))
else:
database_key = None
self.start_time = benchmark_time()
runner = ConjectureRunner(
self.evaluate_test_data,
settings=self.settings,
random=self.random,
database_key=database_key,
)
try:
runner.run()
finally:
self.used_examples_from_database = \
runner.used_examples_from_database
note_engine_for_statistics(runner)
run_time = benchmark_time() - self.start_time
self.used_examples_from_database = runner.used_examples_from_database
if runner.used_examples_from_database:
if self.settings.derandomize:
note_deprecation((
'In future derandomize will imply database=None, but your '
'test: %s is currently using examples from the database. '
'To get the future behaviour, update your settings to '
'include database=None.') % (self.test.__name__, ))
if self.__had_seed:
note_deprecation(
('In future use of @seed will imply database=None in your '
'settings, but your test: %s is currently using examples '
'from the database. To get the future behaviour, update '
'your settings for this test to include database=None.') %
(self.test.__name__, ))
timed_out = runner.exit_reason == ExitReason.timeout
if runner.call_count == 0:
return
if runner.interesting_examples:
self.falsifying_examples = sorted(
[d for d in runner.interesting_examples.values()],
key=lambda d: sort_key(d.buffer),
reverse=True)
else:
if runner.valid_examples == 0:
if timed_out:
raise Timeout(
('Ran out of time before finding a satisfying '
'example for %s. Only found %d examples in %.2fs.') %
(get_pretty_function_description(
self.test), runner.valid_examples, run_time))
else:
raise Unsatisfiable(
'Unable to satisfy assumptions of hypothesis %s.' %
(get_pretty_function_description(self.test), ))
if not self.falsifying_examples:
return
self.failed_normally = True
flaky = 0
for falsifying_example in self.falsifying_examples:
ran_example = ConjectureData.for_buffer(falsifying_example.buffer)
self.__was_flaky = False
assert falsifying_example.__expected_exception is not None
try:
self.execute(ran_example,
print_example=True,
is_final=True,
expected_failure=(
falsifying_example.__expected_exception,
falsifying_example.__expected_traceback,
))
except (UnsatisfiedAssumption, StopTest):
report(traceback.format_exc())
self.__flaky(
'Unreliable assumption: An example which satisfied '
'assumptions on the first run now fails it.')
except BaseException as e:
if len(self.falsifying_examples) <= 1:
raise
tb = get_trimmed_traceback()
report(''.join(traceback.format_exception(type(e), e, tb)))
finally: # pragma: no cover
# This section is in fact entirely covered by the tests in
# test_reproduce_failure, but it seems to trigger a lovely set
# of coverage bugs: The branches show up as uncovered (despite
# definitely being covered - you can add an assert False else
# branch to verify this and see it fail - and additionally the
# second branch still complains about lack of coverage even if
# you add a pragma: no cover to it!
# See https://bitbucket.org/ned/coveragepy/issues/623/
if self.settings.print_blob is not PrintSettings.NEVER:
failure_blob = encode_failure(falsifying_example.buffer)
# Have to use the example we actually ran, not the original
# falsifying example! Otherwise we won't catch problems
# where the repr of the generated example doesn't parse.
can_use_repr = ran_example.can_reproduce_example_from_repr
if (self.settings.print_blob is PrintSettings.ALWAYS or
(self.settings.print_blob is PrintSettings.INFER
and self.settings.verbosity >= Verbosity.normal
and not can_use_repr and len(failure_blob) < 200)):
report((
'\n'
'You can reproduce this example by temporarily '
'adding @reproduce_failure(%r, %r) as a decorator '
'on your test case') % (
__version__,
failure_blob,
))
if self.__was_flaky:
flaky += 1
# If we only have one example then we should have raised an error or
# flaky prior to this point.
assert len(self.falsifying_examples) > 1
if flaky > 0:
raise Flaky(
('Hypothesis found %d distinct failures, but %d of them '
'exhibited some sort of flaky behaviour.') %
(len(self.falsifying_examples), flaky))
else:
raise MultipleFailures(('Hypothesis found %d distinct failures.') %
(len(self.falsifying_examples, )))
def wrapped_test(*arguments, **kwargs):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
test = wrapped_test.hypothesis.inner_test
if getattr(test, "is_hypothesis_test", False):
raise InvalidArgument(
(
"You have applied @given to the test %s more than once, which "
"wraps the test several times and is extremely slow. A "
"similar effect can be gained by combining the arguments "
"of the two calls to given. For example, instead of "
"@given(booleans()) @given(integers()), you could write "
"@given(booleans(), integers())"
)
% (test.__name__,)
)
settings = wrapped_test._hypothesis_internal_use_settings
random = get_random_for_wrapped_test(test, wrapped_test)
if infer in generator_kwargs.values():
hints = get_type_hints(test)
for name in [
name for name, value in generator_kwargs.items() if value is infer
]:
if name not in hints:
raise InvalidArgument(
"passed %s=infer for %s, but %s has no type annotation"
% (name, test.__name__, name)
)
generator_kwargs[name] = st.from_type(hints[name])
processed_args = process_arguments_to_given(
wrapped_test,
arguments,
kwargs,
generator_arguments,
generator_kwargs,
argspec,
test,
settings,
)
arguments, kwargs, test_runner, search_strategy = processed_args
runner = getattr(search_strategy, "runner", None)
if isinstance(runner, TestCase) and test.__name__ in dir(TestCase):
msg = (
"You have applied @given to the method %s, which is "
"used by the unittest runner but is not itself a test."
" This is not useful in any way." % test.__name__
)
fail_health_check(settings, msg, HealthCheck.not_a_test_method)
if bad_django_TestCase(runner): # pragma: no cover
# Covered by the Django tests, but not the pytest coverage task
raise InvalidArgument(
"You have applied @given to a method on %s, but this "
"class does not inherit from the supported versions in "
"`hypothesis.extra.django`. Use the Hypothesis variants "
"to ensure that each example is run in a separate "
"database transaction." % qualname(type(runner))
)
state = StateForActualGivenExecution(
test_runner,
search_strategy,
test,
settings,
random,
had_seed=wrapped_test._hypothesis_internal_use_seed,
)
reproduce_failure = wrapped_test._hypothesis_internal_use_reproduce_failure
if reproduce_failure is not None:
expected_version, failure = reproduce_failure
if expected_version != __version__:
raise InvalidArgument(
(
"Attempting to reproduce a failure from a different "
"version of Hypothesis. This failure is from %s, but "
"you are currently running %r. Please change your "
"Hypothesis version to a matching one."
)
% (expected_version, __version__)
)
try:
state.execute(
ConjectureData.for_buffer(decode_failure(failure)),
print_example=True,
is_final=True,
)
raise DidNotReproduce(
"Expected the test to raise an error, but it "
"completed successfully."
)
except StopTest:
raise DidNotReproduce(
"The shape of the test data has changed in some way "
"from where this blob was defined. Are you sure "
"you're running the same test?"
)
except UnsatisfiedAssumption:
raise DidNotReproduce(
"The test data failed to satisfy an assumption in the "
"test. Have you added it since this blob was "
"generated?"
)
execute_explicit_examples(
test_runner, test, wrapped_test, settings, arguments, kwargs
)
if settings.max_examples <= 0:
return
if not (
Phase.reuse in settings.phases or Phase.generate in settings.phases
):
return
try:
if isinstance(runner, TestCase) and hasattr(runner, "subTest"):
subTest = runner.subTest
try:
setattr(runner, "subTest", fake_subTest)
state.run()
finally:
setattr(runner, "subTest", subTest)
else:
state.run()
except BaseException as e:
generated_seed = wrapped_test._hypothesis_internal_use_generated_seed
with local_settings(settings):
if not (state.failed_normally or generated_seed is None):
if running_under_pytest:
report(
"You can add @seed(%(seed)d) to this test or "
"run pytest with --hypothesis-seed=%(seed)d "
"to reproduce this failure." % {"seed": generated_seed}
)
else:
report(
"You can add @seed(%d) to this test to "
"reproduce this failure." % (generated_seed,)
)
# The dance here is to avoid showing users long tracebacks
# full of Hypothesis internals they don't care about.
# We have to do this inline, to avoid adding another
# internal stack frame just when we've removed the rest.
if PY2:
# Python 2 doesn't have Exception.with_traceback(...);
# instead it has a three-argument form of the `raise`
# statement. Unfortunately this is a SyntaxError on
# Python 3, and before Python 2.7.9 it was *also* a
# SyntaxError to use it in a nested function so we
# can't `exec` or `eval` our way out (BPO-21591).
# So unless we break some versions of Python 2, none
# of them get traceback elision.
raise
# On Python 3, we swap out the real traceback for our
# trimmed version. Using a variable ensures that the line
# which will actually appear in trackbacks is as clear as
# possible - "raise the_error_hypothesis_found".
the_error_hypothesis_found = e.with_traceback(
get_trimmed_traceback()
)
raise the_error_hypothesis_found
def run(self):
# Tell pytest to omit the body of this function from tracebacks
__tracebackhide__ = True
if global_force_seed is None:
database_key = function_digest(self.test)
else:
database_key = None
runner = ConjectureRunner(
self.evaluate_test_data,
settings=self.settings,
random=self.random,
database_key=database_key,
)
try:
runner.run()
finally:
self.used_examples_from_database = runner.used_examples_from_database
note_engine_for_statistics(runner)
self.used_examples_from_database = runner.used_examples_from_database
if runner.call_count == 0:
return
if runner.interesting_examples:
self.falsifying_examples = sorted(
[d for d in runner.interesting_examples.values()],
key=lambda d: sort_key(d.buffer),
reverse=True,
)
else:
if runner.valid_examples == 0:
raise Unsatisfiable(
"Unable to satisfy assumptions of hypothesis %s."
% (get_pretty_function_description(self.test),)
)
if not self.falsifying_examples:
return
elif not self.settings.report_multiple_bugs:
del self.falsifying_examples[:-1]
self.failed_normally = True
flaky = 0
for falsifying_example in self.falsifying_examples:
info = falsifying_example.extra_information
ran_example = ConjectureData.for_buffer(falsifying_example.buffer)
self.__was_flaky = False
assert info.__expected_exception is not None
try:
self.execute(
ran_example,
print_example=True,
is_final=True,
expected_failure=(
info.__expected_exception,
info.__expected_traceback,
),
)
except (UnsatisfiedAssumption, StopTest):
report(traceback.format_exc())
self.__flaky(
"Unreliable assumption: An example which satisfied "
"assumptions on the first run now fails it."
)
except BaseException as e:
if len(self.falsifying_examples) <= 1:
raise
tb = get_trimmed_traceback()
report("".join(traceback.format_exception(type(e), e, tb)))
finally: # pragma: no cover
# This section is in fact entirely covered by the tests in
# test_reproduce_failure, but it seems to trigger a lovely set
# of coverage bugs: The branches show up as uncovered (despite
# definitely being covered - you can add an assert False else
# branch to verify this and see it fail - and additionally the
# second branch still complains about lack of coverage even if
# you add a pragma: no cover to it!
# See https://bitbucket.org/ned/coveragepy/issues/623/
if self.settings.print_blob is not PrintSettings.NEVER:
failure_blob = encode_failure(falsifying_example.buffer)
# Have to use the example we actually ran, not the original
# falsifying example! Otherwise we won't catch problems
# where the repr of the generated example doesn't parse.
can_use_repr = ran_example.can_reproduce_example_from_repr
if self.settings.print_blob is PrintSettings.ALWAYS or (
self.settings.print_blob is PrintSettings.INFER
and self.settings.verbosity >= Verbosity.normal
and not can_use_repr
and len(failure_blob) < 200
):
report(
(
"\nYou can reproduce this example by temporarily "
"adding @reproduce_failure(%r, %r) as a decorator "
"on your test case"
)
% (__version__, failure_blob)
)
if self.__was_flaky:
flaky += 1
# If we only have one example then we should have raised an error or
# flaky prior to this point.
assert len(self.falsifying_examples) > 1
if flaky > 0:
raise Flaky(
(
"Hypothesis found %d distinct failures, but %d of them "
"exhibited some sort of flaky behaviour."
)
% (len(self.falsifying_examples), flaky)
)
else:
raise MultipleFailures(
("Hypothesis found %d distinct failures.")
% (len(self.falsifying_examples))
)