def test_method_race_with_failing_promises(self):
class MyException(Exception):
pass
_reject_promise = []
def _failing_async_promise(_ok, error):
_reject_promise.append(error)
promises = [Promise(_failing_async_promise) for _ in range(0, 15)]
p = Promise.race(promises)
with pytest.raises(TimeoutError):
p.result(0)
random.shuffle(_reject_promise)
reject = _reject_promise.pop(0)
reject(MyException())
assert isinstance(p.exception(0.001), MyException)
# subsequent rejection are ignored
for reject in _reject_promise:
reject(ValueError())
assert isinstance(p.exception(0.001), MyException)
def test_method_race_with_several_promises(self):
_resolve_callback = []
def _async_promise(ok, _error):
_resolve_callback.append(ok)
# Add non-resolving promises.
promises = [Promise(lambda _ok, _err: None) for _ in range(0, 5)]
promises.append(Promise(_async_promise))
promises.append(Promise(_async_promise))
# Add non-resolving promises.
promises += [Promise(lambda _ok, _err: None) for _ in range(0, 5)]
p = Promise.race(promises)
with pytest.raises(TimeoutError):
p.result(0)
_resolve_callback[0]('RESULT')
# p is resolved after the first Promise resolves.
assert p.result(0.001) == 'RESULT'
# subsequent Promises resolutions should have no effect.
_resolve_callback[1]('RESULT2')
assert p.result(0.001) == 'RESULT'
def test_method_race_with_one_promise(self):
p1 = Promise.resolve('RESULT')
p = Promise.race([p1])
assert p.result(0.001) == 'RESULT'
def test_method_race_with_empty_set(self):
with pytest.raises(ValueError):
Promise.race([])
