nim-chronos/tests/testutils.nim

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# Chronos Test Suite
# (c) Copyright 2020-Present
# Status Research & Development GmbH
#
# Licensed under either of
# Apache License, version 2.0, (LICENSE-APACHEv2)
# MIT license (LICENSE-MIT)
exception tracking (#166) * exception tracking This PR adds minimal exception tracking to chronos, moving the goalpost one step further. In particular, it becomes invalid to raise exceptions from `callSoon` callbacks: this is critical for writing correct error handling because there's no reasonable way that a user of chronos can possibly _reason_ about exceptions coming out of there: the event loop will be in an indeterminite state when the loop is executing an _random_ callback. As expected, there are several issues in the error handling of chronos: in particular, it will end up in an inconsistent internal state whenever the selector loop operations fail, because the internal state update functions are not written in an exception-safe way. This PR turns this into a Defect, which probably is not the optimal way of handling things - expect more work to be done here. Some API have no way of reporting back errors to callers - for example, when something fails in the accept loop, there's not much it can do, and no way to report it back to the user of the API - this has been fixed with the new accept flow - the old one should be deprecated. Finally, there is information loss in the API: in composite operations like `poll` and `waitFor` there's no way to differentiate internal errors from user-level errors originating from callbacks. * store `CatchableError` in future * annotate proc's with correct raises information * `selectors2` to avoid non-CatchableError IOSelectorsException * `$` should never raise * remove unnecessary gcsafe annotations * fix exceptions leaking out of timer waits * fix some imports * functions must signal raising the union of all exceptions across all platforms to enable cross-platform code * switch to unittest2 * add `selectors2` which supercedes the std library version and fixes several exception handling issues in there * fixes * docs, platform-independent eh specifiers for some functions * add feature flag for strict exception mode also bump version to 3.0.0 - _most_ existing code should be compatible with this version of exception handling but some things might need fixing - callbacks, existing raises specifications etc. * fix AsyncCheck for non-void T
2021-03-24 09:08:33 +00:00
import unittest2
import ../chronos, ../chronos/config
{.used.}
suite "Asynchronous utilities test suite":
when chronosFutureTracking:
proc getCount(): uint =
# This procedure counts number of Future[T] in double-linked list via list
# iteration.
var res = 0'u
for item in pendingFutures():
inc(res)
res
test "Future clean and leaks test":
when chronosFutureTracking:
if pendingFuturesCount(WithoutCompleted) == 0'u:
if pendingFuturesCount(OnlyCompleted) > 0'u:
poll()
check pendingFuturesCount() == 0'u
else:
echo dumpPendingFutures()
check false
else:
skip()
test "FutureList basics test":
when chronosFutureTracking:
var fut1 = newFuture[void]()
check:
getCount() == 1'u
pendingFuturesCount() == 1'u
var fut2 = newFuture[void]()
check:
getCount() == 2'u
pendingFuturesCount() == 2'u
var fut3 = newFuture[void]()
check:
getCount() == 3'u
pendingFuturesCount() == 3'u
fut1.complete()
poll()
check:
getCount() == 2'u
pendingFuturesCount() == 2'u
fut2.fail(newException(ValueError, ""))
poll()
check:
getCount() == 1'u
pendingFuturesCount() == 1'u
discard fut3.tryCancel()
poll()
check:
getCount() == 0'u
pendingFuturesCount() == 0'u
else:
skip()
test "FutureList async procedure test":
when chronosFutureTracking:
proc simpleProc() {.async.} =
await sleepAsync(10.milliseconds)
var fut = simpleProc()
check:
getCount() == 2'u
pendingFuturesCount() == 2'u
waitFor fut
check:
getCount() == 0'u
pendingFuturesCount() == 0'u
else:
skip()