import functools
import unittest
import six
[docs]class QuietTestRunner(object):
[docs] def run(self, suite):
result = unittest.TestResult()
suite(result)
return result
[docs]def repeat_with_success_at_least(times, min_success):
"""Decorator for multiple trial of the test case.
The decorated test case is launched multiple times.
The case is judged as passed at least specified number of trials.
If the number of successful trials exceeds `min_success`,
the remaining trials are skipped.
Args:
times(int): The number of trials.
min_success(int): Threshold that the decorated test
case is regarded as passed.
"""
assert times >= min_success
def _repeat_with_success_at_least(f):
@functools.wraps(f)
def wrapper(*args, **kwargs):
assert len(args) > 0
instance = args[0]
assert isinstance(instance, unittest.TestCase)
success_counter = 0
failure_counter = 0
results = []
def fail():
msg = '\nFail: {0}, Success: {1}'.format(
failure_counter, success_counter)
if len(results) > 0:
first = results[0]
errs = first.failures + first.errors
if len(errs) > 0:
err_msg = '\n'.join(fail[1] for fail in errs)
msg += '\n\nThe first error message:\n' + err_msg
instance.fail(msg)
for _ in six.moves.range(times):
suite = unittest.TestSuite()
# Create new instance to call the setup and the teardown only
# once.
ins = type(instance)(instance._testMethodName)
suite.addTest(
unittest.FunctionTestCase(
lambda: f(ins, *args[1:], **kwargs),
setUp=ins.setUp,
tearDown=ins.tearDown))
result = QuietTestRunner().run(suite)
if result.wasSuccessful():
success_counter += 1
else:
results.append(result)
failure_counter += 1
if success_counter >= min_success:
instance.assertTrue(True)
return
if failure_counter > times - min_success:
fail()
return
fail()
return wrapper
return _repeat_with_success_at_least
[docs]def retry(times):
"""Decorator that imposes the test to be successful at least once.
Decorated test case is launched multiple times.
The case is regarded as passed if it is successful
at least once.
.. note::
In current implementation, this decorator grasps the
failure information of each trial.
Args:
times(int): The number of trials.
"""
return repeat_with_success_at_least(times, 1)