使用TimeoutMixin时扭曲单元测试“反应堆不干净”

Question

我正在实现一个协议，该协议可以用不同的超时来实例化，所以我使用TimeoutMixin。这个想法可以用这个虚拟类来表示：

my_protocol.py

from twisted.protocols import basic, policies
from twisted.internet import protocol

class MyProtocol(basic.LineReceiver, policies.TimeoutMixin):
    def __init__(self, timeout):
        self.setTimeout(timeout)

    def lineReceived(self, line):
        self.transport.write(line)

为了使用扭曲试验对其进行测试，a大致按照official tutorial进行了单元测试：

测试我的协议.py

from twisted.trial import unittest
from twisted.test import proto_helpers

import my_protocol

class TestMyProtocol(unittest.TestCase):
    def setUp(self):
        self.protocol = my_protocol.MyProtocol(1)
        self.transport = proto_helpers.StringTransport()
        self.protocol.makeConnection(self.transport)

    def test_echo(self):
        self.protocol.lineReceived(b"test")
        self.assertEqual(self.transport.value(), b"test")

    def tearDown(self):
        self.protocol.transport.loseConnection()

我在运行测试时遇到以下错误：

$ python -m twisted.trial test_my_protocol
test_my_protocol
  TestMyProtocol
    test_echo ...                                                       [ERROR]

===============================================================================
[ERROR]
Traceback (most recent call last):
Failure: twisted.trial.util.DirtyReactorAggregateError: Reactor was unclean.
DelayedCalls: (set twisted.internet.base.DelayedCall.debug = True to debug)
<DelayedCall 0x7ff1f9a8d070 [0.9994857311248779s] called=0 cancelled=0 TimeoutMixin.__timedOut()>

test_my_protocol.TestMyProtocol.test_echo
-------------------------------------------------------------------------------
Ran 1 tests in 0.011s

FAILED (errors=1)

这是official docs关于这个主题所说的：

Calls to reactor.callLater create IDelayedCall s. These need to be run or cancelled during a test, otherwise they will outlive the test. This would be bad, because they could interfere with a later test, causing confusing failures in unrelated tests! For this reason, Trial checks the reactor to make sure there are no leftover IDelayedCall s in the reactor after a test, and will fail the test if there are. The cleanest and simplest way to make sure this all works is to return a Deferred from your test.

但我不知道如果超时混合该怎么办

Answer 1

您已将协议连接到proto_helpers.StringTransport。在许多方面，这是一件好事，对测试是有益的。然而，一个缺点是StringTransport没有实现loseConnection您可能会做的事情。它所做的只是记录调用该方法的事实。它不会将通知传递到您的协议

幸运的是，有StringTransportWithDisconnection，将通知传递给协议。如果切换到该选项，则将调用协议的connectionLost方法。那么您还需要另一个更改TimeoutMixin在调用connectionLost时不会自动取消其超时。因此，您需要将connectionLost添加到调用self.setTimeout(None)的协议中