in later/unittest/backport/mock.py [0:0]
def decoration_helper(self, patched, args, keywargs):
extra_args = []
entered_patchers = []
patching = None
exc_info = tuple()
try:
for patching in patched.patchings:
arg = patching.__enter__()
entered_patchers.append(patching)
if patching.attribute_name is not None:
keywargs.update(arg)
elif patching.new is DEFAULT:
extra_args.append(arg)
args += tuple(extra_args)
yield (args, keywargs)
except:
if (patching not in entered_patchers and
_is_started(patching)):
# the patcher may have been started, but an exception
# raised whilst entering one of its additional_patchers
entered_patchers.append(patching)
# Pass the exception to __exit__
exc_info = sys.exc_info()
# re-raise the exception
raise
finally:
for patching in reversed(entered_patchers):
patching.__exit__(*exc_info)