async def test_coro_reject(self):
p = Promise(success_sleep(), loop=self.loop)
with self.assertRaisesRegex(RuntimeError, "Task does not support set_exception operation"):
p.reject(Exception("Should Fail"))
self.assertEqual(await p, SUCCESS_RESULT)
async def test_resolution(self):
promise = Promise(self.fut)
promise.resolve(None)
result = await promise
self.assertIsNone(result)
self.assertEqual(await self.fut, result)
async def test_rejection(self):
promise = Promise(self.fut, log_unhandled_exception=False)
exc = Exception("test_rejection")
promise.reject(exc)
self.assertAsyncRaises(exc, promise)
self.assertAsyncRaises(exc, self.fut)
async def test_coro_resolve(self):
p = Promise(success_sleep(), loop=self.loop)
with self.assertRaisesRegex(RuntimeError, "Task does not support set_result operation"):
p.resolve(None)
self.assertEqual(await p, SUCCESS_RESULT)
async def test_promise_of_a_promise(self):
p = Promise()
p2 = Promise(p)
p.resolve(0)
self.assertEqual(await p2.then(lambda x: 1 / x).catch(lambda exc: 0),
0)
async def test_external_resolution(self):
promise = Promise(self.fut)
self.fut.set_result(None)
result = await self.fut
self.assertIsNone(result, None)
self.assertEqual(result, await promise)
async def test_catch(self):
p = Promise(division_by_0())
with self.assertRaises(ZeroDivisionError):
await p
self.assertTrue(
await p.catch(lambda exc: isinstance(exc, ZeroDivisionError)))
async def test_lastly_simple_error(self):
counter = Counter()
p = Promise(division_by_0()).lastly(lambda: counter.update(["lastly"]))
with self.assertRaises(ZeroDivisionError):
await p
self.assertEqual(counter["lastly"], 1)
async def test_promise_cancelled_2(self):
b = False
async def a():
nonlocal b
b = True
p = Promise()
lp = p.lastly(a)
p.resolve(10)
lp.cancel()
with self.assertRaises(CancelledError):
await lp
self.assertEqual(await p, 10)
self.assertFalse(b)
async def test_promise_cancelled(self):
b = False
async def a():
nonlocal b
b = True
p = Promise()
lp = p.lastly(a)
p.cancel()
with self.assertRaises(CancelledError):
await p
with self.assertRaises(CancelledError):
await lp
self.assertFalse(b)
async def test_then_chain_timing(self):
p = Promise().resolve(10)
start_time = self.loop.time()
result = (await p.then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)
).then(lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)).then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)
).then(lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)).then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)
).then(lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)).then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)).then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)).then(
lambda x: Promise(sum_with_sleep(x, 10), loop=self.loop)))
end_time = self.loop.time()
self.assertEqual(result, 100)
self.assertAlmostEqual(DEFAULT_SLEEP * 9,
end_time - start_time,
delta=0.05)
async def test_catch_continue_chain(self):
counter = Counter()
p = (Promise(division_by_0()).catch(
lambda _: counter.update(["catch"]) or UNIQUE).then(
lambda val: counter.update(["then"]) or val is UNIQUE).catch(
lambda exc: counter.update(["catch"])))
self.assertTrue(await p)
self.assertEqual(counter["catch"], 1)
self.assertEqual(counter["then"], 1)
async def test_catch_mid_chain(self):
counter = Counter()
p = Promise(division_by_0()).then(
lambda num: counter.update(["then"]) or num + 10)
with self.assertRaises(ZeroDivisionError):
await p
self.assertTrue(
await p.catch(lambda exc: isinstance(exc, ZeroDivisionError)))
self.assertEqual(counter["then"], 0)
async def test_future_log_traceback(self):
import gc
fut = self.loop.create_future()
fut.set_exception(RuntimeError)
p = Promise(fut)
del fut, p
gc.collect()
await sleep(0)
async def test_cancellation_managed(self):
with Promise() as p:
t = p.then(lambda x: x * 2)
t.cancel()
with self.assertRaises(CancelledError):
await t
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertTrue(p.done())
self.assertTrue(p.cancelled())
async def test_chain_after_cancellation_after_resolution(self):
with Promise() as p:
p.resolve(10)
self.assertEqual(await p, 10)
t1 = p.then(lambda x: x * 2)
self.assertEqual(await t1, 20)
t2 = t1.then(lambda x: sum_with_sleep(x, 10))
with self.assertRaises(CancelledError):
await t2
async def test_ignore_unhandled_exception_2(self):
async def raise_exc():
raise RuntimeError
p = Promise(raise_exc()).catch(lambda exc: "success")
await p._fut # bypass promise __await__
# Wait till next loop cycle
await sleep(0)
self.assertEqual(self.exc_ctx_count, 0)
self.assertIsNone(self.exc_ctx)
self.assertEqual(await p, "success")
async def test_chain_no_external_resolve(self):
with Promise() as p:
self.assertTrue(callable(getattr(p, "resolve")))
self.assertTrue(callable(getattr(p, "reject")))
t = p.then(lambda x: x * 2)
self.assertFalse(hasattr(t, "resolve"))
self.assertFalse(hasattr(t, "reject"))
p.resolve(10)
result = await t
self.assertEqual(result, 20)
async def test_ignore_unhandled_exception_3(self):
async def raise_exc():
raise RuntimeError
p = Promise(raise_exc())
with self.assertRaises(RuntimeError):
await p
# Wait till next loop cycle
await sleep(0.1)
self.assertEqual(self.exc_ctx_count, 0)
self.assertIsNone(self.exc_ctx)
async def test_chain_cancellation_sync(self):
with Promise() as p:
p.resolve(10)
t1 = p.then(lambda x: x * 2)
t2 = t1.then(lambda x: x * 2)
t3 = t2.then(lambda x: x * 2)
self.assertEqual(await p, 10)
with self.assertRaises(CancelledError):
await p._notify_chain
self.assertEqual(await t1, 20)
self.assertEqual(await t2, 40)
self.assertEqual(await t3, 80)
async def test_cancellation_managed_2(self):
with Promise() as p:
p.resolve(10)
t = p.then(lambda x: x * 2)
t.cancel()
with self.assertRaises(CancelledError):
await t
self.assertEqual(await p, 10)
self.assertTrue(t.done())
self.assertTrue(t.cancelled())
self.assertTrue(p.done())
self.assertTrue(p.cancelled())
async def test_catch_fails_and_recover(self):
counter = Counter()
def fails_catch(exc):
self.assertIsInstance(exc, ZeroDivisionError)
counter.update(["catch"])
raise RuntimeError
self.assertIs(
await (Promise(division_by_0()).catch(fails_catch).catch(
lambda exc: self.assertIsInstance(exc, RuntimeError) or self.
assertIsInstance(exc.__context__, ZeroDivisionError
) or counter.update(["catch"]) or UNIQUE)),
UNIQUE,
)
self.assertEqual(counter["catch"], 2)
async def test_catch_fails(self):
counter = Counter()
def fails_catch(prop_exc):
self.assertIsInstance(prop_exc, ZeroDivisionError)
counter.update(["catch"])
raise RuntimeError
try:
await (Promise(division_by_0()).catch(fails_catch))
except RuntimeError as exc:
self.assertIsInstance(exc.__context__, ZeroDivisionError)
else:
self.fail("Promise should not have succeeded")
self.assertEqual(counter["catch"], 1)
async def test_chain_cancellation_branch(self):
with Promise() as p:
p.resolve(10)
t1 = p.then(lambda x: sum_with_sleep(x, 10))
t2 = p.then(lambda x: x * 2)
t3 = p.then(lambda x: sum_with_sleep(x, 10))
t1.cancel()
self.assertEqual(await p, 10)
with self.assertRaises(CancelledError):
await t1
self.assertEqual(await t2, 20)
self.assertEqual(await t3, 20)
async def test_ignore_unhandled_cancellation_error(self):
fut = self.loop.create_future()
p = Promise(fut)
fut.cancel()
with self.assertRaises(CancelledError):
await fut
# Wait till next loop cycle
await sleep(0)
self.assertEqual(self.exc_ctx_count, 0)
self.assertIsNone(self.exc_ctx)
with self.assertRaises(CancelledError):
await p
async def test_internal_state(self):
promise = Promise(success_sleep(), loop=self.loop)
self.assertEqual(promise.loop, self.loop)
self.assertEqual(promise.done(), False)
self.assertEqual(promise.cancelled(), False)
await promise
self.assertEqual(promise.loop, self.loop)
self.assertEqual(promise.done(), True)
self.assertEqual(promise.cancelled(), False)
async def test_promise_cancellation_after_result(self):
p = Promise()
counter = Counter()
p.cancel()
with self.assertRaises(CancelledError):
await (p.then(lambda x: counter.update(["then"])).catch(
lambda exc: counter.update(["catch"])).lastly(
lambda: counter.update(["lastly"])))
self.assertTrue(p.done())
self.assertTrue(p.cancelled())
self.assertEqual(counter["then"], 0)
self.assertEqual(counter["catch"], 0)
self.assertEqual(counter["lastly"], 0)
async def test_ignore_unhandled_exception(self):
async def raise_exc():
raise RuntimeError
task = self.loop.create_task(raise_exc())
p = Promise(task, log_unhandled_exception=False)
with self.assertRaises(RuntimeError):
await task
# Wait till next loop cycle
await sleep(0)
self.assertEqual(self.exc_ctx_count, 0)
self.assertIsNone(self.exc_ctx)
with self.assertRaises(RuntimeError):
await p
async def test_task_cancellation(self):
a = {}
async def task(_):
t1.cancel()
a["test"] = 10
await asleep(DEFAULT_SLEEP)
a["shouldnt_exist"] = 10
with Promise() as p:
p.resolve(10)
t1 = p.then(task)
self.assertNotIn("test", a)
self.assertNotIn("shouldnt_exist", a)
with self.assertRaises(CancelledError):
await t1
self.assertIn("test", a)
self.assertNotIn("shouldnt_exist", a)
async def test_unhandled_exception_2(self):
async def raise_exc(_):
raise RuntimeError
p = Promise(raise_exc(None)).catch(raise_exc)
with self.assertRaises(RuntimeError):
await p._fut # bypass promise __await__
# Wait till next loop cycle
await sleep(0)
self.assertEqual(self.exc_ctx_count, 1)
self.assertIsNotNone(self.exc_ctx)
self.assertIn("message", self.exc_ctx)
self.assertIsInstance(self.exc_ctx["exception"], RuntimeError)
with self.assertRaises(RuntimeError):
await p
