# -*- test-case-name: twisted.trial.test.test_tests -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Definitions of test cases with various interesting error-related behaviors, to
be used by test modules to exercise different features of trial's test runner.
See the L{twisted.trial.test.test_tests} module docstring for details about how
this code is arranged.
Some of these tests are also used by L{twisted.trial._dist.test}.
"""
from unittest import skipIf
from twisted.internet import defer, protocol, reactor
from twisted.internet.task import deferLater
from twisted.trial import unittest, util
class FoolishError(Exception):
pass
class LargeError(Exception):
"""
An exception which has a string representation of at least a specified
number of characters.
"""
def __init__(self, minSize: int) -> None:
Exception.__init__(self)
self.minSize = minSize
def __str__(self):
large = "x" * self.minSize
return f"LargeError<I fail: {large}>"
class FailureInSetUpMixin:
def setUp(self):
raise FoolishError("I am a broken setUp method")
def test_noop(self):
pass
class SynchronousTestFailureInSetUp(FailureInSetUpMixin, unittest.SynchronousTestCase):
pass
class AsynchronousTestFailureInSetUp(FailureInSetUpMixin, unittest.TestCase):
pass
class FailureInTearDownMixin:
def tearDown(self):
raise FoolishError("I am a broken tearDown method")
def test_noop(self):
pass
class SynchronousTestFailureInTearDown(
FailureInTearDownMixin, unittest.SynchronousTestCase
):
pass
class AsynchronousTestFailureInTearDown(FailureInTearDownMixin, unittest.TestCase):
pass
class FailureButTearDownRunsMixin:
"""
A test fails, but its L{tearDown} still runs.
"""
tornDown = False
def tearDown(self):
self.tornDown = True
def test_fails(self):
"""
A test that fails.
"""
raise FoolishError("I am a broken test")
class SynchronousTestFailureButTearDownRuns(
FailureButTearDownRunsMixin, unittest.SynchronousTestCase
):
pass
class AsynchronousTestFailureButTearDownRuns(
FailureButTearDownRunsMixin, unittest.TestCase
):
pass
class TestRegularFail(unittest.SynchronousTestCase):
def test_fail(self):
self.fail("I fail")
def test_subfail(self):
self.subroutine()
def subroutine(self):
self.fail("I fail inside")
class TestAsynchronousFail(unittest.TestCase):
"""
Test failures for L{unittest.TestCase} based classes.
"""
text = "I fail"
def test_fail(self) -> defer.Deferred[None]:
"""
A test which fails in the callback of the returned L{defer.Deferred}.
"""
return deferLater(reactor, 0, self.fail, "I fail later") # type: ignore[arg-type]
def test_failGreaterThan64k(self) -> defer.Deferred[None]:
"""
A test which fails in the callback of the returned L{defer.Deferred}
with a very long string.
"""
return deferLater(reactor, 0, self.fail, "I fail later: " + "x" * 2**16) # type: ignore[arg-type]
def test_exception(self) -> None:
"""
A test which raises an exception synchronously.
"""
raise Exception(self.text)
def test_exceptionGreaterThan64k(self) -> None:
"""
A test which raises an exception with a long string representation
synchronously.
"""
raise LargeError(2**16)
def test_exceptionGreaterThan64kEncoded(self) -> None:
"""
A test which synchronously raises an exception with a long string
representation including non-ascii content.
"""
# The exception text itself is not greater than 64k but SNOWMAN
# encodes to 3 bytes with UTF-8 so the length of the UTF-8 encoding of
# the string representation of this exception will be greater than 2
# ** 16.
raise Exception("\N{SNOWMAN}" * 2**15)
class ErrorTest(unittest.SynchronousTestCase):
"""
A test case which has a L{test_foo} which will raise an error.
@ivar ran: boolean indicating whether L{test_foo} has been run.
"""
ran = False
def test_foo(self):
"""
Set C{self.ran} to True and raise a C{ZeroDivisionError}
"""
self.ran = True
1 / 0
@skipIf(True, "skipping this test")
class TestSkipTestCase(unittest.SynchronousTestCase):
pass
class DelayedCall(unittest.TestCase):
hiddenExceptionMsg = "something blew up"
def go(self):
raise RuntimeError(self.hiddenExceptionMsg)
def testHiddenException(self):
"""
What happens if an error is raised in a DelayedCall and an error is
also raised in the test?
L{test_reporter.ErrorReportingTests.testHiddenException} checks that
both errors get reported.
Note that this behaviour is deprecated. A B{real} test would return a
Deferred that got triggered by the callLater. This would guarantee the
delayed call error gets reported.
"""
reactor.callLater(0, self.go)
reactor.iterate(0.01)
self.fail("Deliberate failure to mask the hidden exception")
testHiddenException.suppress = [ # type: ignore[attr-defined]
util.suppress(
message=r"reactor\.iterate cannot be used.*", category=DeprecationWarning
)
]
class ReactorCleanupTests(unittest.TestCase):
def test_leftoverPendingCalls(self):
def _():
print("foo!")
reactor.callLater(10000.0, _)
class SocketOpenTest(unittest.TestCase):
def test_socketsLeftOpen(self):
f = protocol.Factory()
f.protocol = protocol.Protocol
reactor.listenTCP(0, f)
class TimingOutDeferred(unittest.TestCase):
def test_alpha(self):
pass
def test_deferredThatNeverFires(self):
self.methodCalled = True
d = defer.Deferred()
return d
def test_omega(self):
pass
def unexpectedException(self):
"""i will raise an unexpected exception...
... *CAUSE THAT'S THE KINDA GUY I AM*
>>> 1/0
"""
class EventuallyFailingTestCase(unittest.SynchronousTestCase):
"""
A test suite that fails after it is run a few times.
"""
n: int = 0
def test_it(self):
"""
Run successfully a few times and then fail forever after.
"""
self.n += 1
if self.n >= 5:
self.fail("eventually failing")
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