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- # Copyright (c) Twisted Matrix Laboratories.
- # See LICENSE for details.
-
- """
- Test cases for the L{twisted.python.failure} module.
- """
-
-
- import linecache
- import pdb
- import re
- import sys
- import traceback
- from dis import distb
- from io import StringIO
- from traceback import FrameSummary
- from unittest import skipIf
-
- from cython_test_exception_raiser import raiser # type: ignore[import]
-
- from twisted.python import failure, reflect
- from twisted.trial.unittest import SynchronousTestCase
-
-
- def getDivisionFailure(*args, **kwargs):
- """
- Make a C{Failure} of a divide-by-zero error.
-
- @param args: Any C{*args} are passed to Failure's constructor.
- @param kwargs: Any C{**kwargs} are passed to Failure's constructor.
- """
- try:
- 1 / 0
- except BaseException:
- f = failure.Failure(*args, **kwargs)
- return f
-
-
- class FailureTests(SynchronousTestCase):
- """
- Tests for L{failure.Failure}.
- """
-
- def test_failAndTrap(self):
- """
- Trapping a L{Failure}.
- """
- try:
- raise NotImplementedError("test")
- except BaseException:
- f = failure.Failure()
- error = f.trap(SystemExit, RuntimeError)
- self.assertEqual(error, RuntimeError)
- self.assertEqual(f.type, NotImplementedError)
-
- def test_trapRaisesWrappedException(self):
- """
- If the wrapped C{Exception} is not a subclass of one of the
- expected types, L{failure.Failure.trap} raises the wrapped
- C{Exception}.
- """
- exception = ValueError()
- try:
- raise exception
- except BaseException:
- f = failure.Failure()
-
- untrapped = self.assertRaises(ValueError, f.trap, OverflowError)
- self.assertIs(exception, untrapped)
-
- def test_failureValueFromFailure(self):
- """
- A L{failure.Failure} constructed from another
- L{failure.Failure} instance, has its C{value} property set to
- the value of that L{failure.Failure} instance.
- """
- exception = ValueError()
- f1 = failure.Failure(exception)
- f2 = failure.Failure(f1)
- self.assertIs(f2.value, exception)
-
- def test_failureValueFromFoundFailure(self):
- """
- A L{failure.Failure} constructed without a C{exc_value}
- argument, will search for an "original" C{Failure}, and if
- found, its value will be used as the value for the new
- C{Failure}.
- """
- exception = ValueError()
- f1 = failure.Failure(exception)
- try:
- f1.trap(OverflowError)
- except BaseException:
- f2 = failure.Failure()
-
- self.assertIs(f2.value, exception)
-
- def assertStartsWith(self, s, prefix):
- """
- Assert that C{s} starts with a particular C{prefix}.
-
- @param s: The input string.
- @type s: C{str}
- @param prefix: The string that C{s} should start with.
- @type prefix: C{str}
- """
- self.assertTrue(s.startswith(prefix), f"{prefix!r} is not the start of {s!r}")
-
- def assertEndsWith(self, s, suffix):
- """
- Assert that C{s} end with a particular C{suffix}.
-
- @param s: The input string.
- @type s: C{str}
- @param suffix: The string that C{s} should end with.
- @type suffix: C{str}
- """
- self.assertTrue(s.endswith(suffix), f"{suffix!r} is not the end of {s!r}")
-
- def assertTracebackFormat(self, tb, prefix, suffix):
- """
- Assert that the C{tb} traceback contains a particular C{prefix} and
- C{suffix}.
-
- @param tb: The traceback string.
- @type tb: C{str}
- @param prefix: The string that C{tb} should start with.
- @type prefix: C{str}
- @param suffix: The string that C{tb} should end with.
- @type suffix: C{str}
- """
- self.assertStartsWith(tb, prefix)
- self.assertEndsWith(tb, suffix)
-
- def assertDetailedTraceback(self, captureVars=False, cleanFailure=False):
- """
- Assert that L{printDetailedTraceback} produces and prints a detailed
- traceback.
-
- The detailed traceback consists of a header::
-
- *--- Failure #20 ---
-
- The body contains the stacktrace::
-
- /twisted/trial/_synctest.py:1180: _run(...)
- /twisted/python/util.py:1076: runWithWarningsSuppressed(...)
- --- <exception caught here> ---
- /twisted/test/test_failure.py:39: getDivisionFailure(...)
-
- If C{captureVars} is enabled the body also includes a list of
- globals and locals::
-
- [ Locals ]
- exampleLocalVar : 'xyz'
- ...
- ( Globals )
- ...
-
- Or when C{captureVars} is disabled::
-
- [Capture of Locals and Globals disabled (use captureVars=True)]
-
- When C{cleanFailure} is enabled references to other objects are removed
- and replaced with strings.
-
- And finally the footer with the L{Failure}'s value::
-
- exceptions.ZeroDivisionError: float division
- *--- End of Failure #20 ---
-
- @param captureVars: Enables L{Failure.captureVars}.
- @type captureVars: C{bool}
- @param cleanFailure: Enables L{Failure.cleanFailure}.
- @type cleanFailure: C{bool}
- """
- if captureVars:
- exampleLocalVar = "xyz"
- # Silence the linter as this variable is checked via
- # the traceback.
- exampleLocalVar
-
- f = getDivisionFailure(captureVars=captureVars)
- out = StringIO()
- if cleanFailure:
- f.cleanFailure()
- f.printDetailedTraceback(out)
-
- tb = out.getvalue()
- start = "*--- Failure #%d%s---\n" % (
- f.count,
- (f.pickled and " (pickled) ") or " ",
- )
- end = "{}: {}\n*--- End of Failure #{} ---\n".format(
- reflect.qual(f.type),
- reflect.safe_str(f.value),
- f.count,
- )
- self.assertTracebackFormat(tb, start, end)
-
- # Variables are printed on lines with 2 leading spaces.
- linesWithVars = [line for line in tb.splitlines() if line.startswith(" ")]
-
- if captureVars:
- self.assertNotEqual([], linesWithVars)
- if cleanFailure:
- line = " exampleLocalVar : \"'xyz'\""
- else:
- line = " exampleLocalVar : 'xyz'"
- self.assertIn(line, linesWithVars)
- else:
- self.assertEqual([], linesWithVars)
- self.assertIn(
- " [Capture of Locals and Globals disabled (use " "captureVars=True)]\n",
- tb,
- )
-
- def assertBriefTraceback(self, captureVars=False):
- """
- Assert that L{printBriefTraceback} produces and prints a brief
- traceback.
-
- The brief traceback consists of a header::
-
- Traceback: <type 'exceptions.ZeroDivisionError'>: float division
-
- The body with the stacktrace::
-
- /twisted/trial/_synctest.py:1180:_run
- /twisted/python/util.py:1076:runWithWarningsSuppressed
-
- And the footer::
-
- --- <exception caught here> ---
- /twisted/test/test_failure.py:39:getDivisionFailure
-
- @param captureVars: Enables L{Failure.captureVars}.
- @type captureVars: C{bool}
- """
- if captureVars:
- exampleLocalVar = "abcde"
- # Silence the linter as this variable is checked via
- # the traceback.
- exampleLocalVar
-
- f = getDivisionFailure()
- out = StringIO()
- f.printBriefTraceback(out)
- tb = out.getvalue()
- stack = ""
- for method, filename, lineno, localVars, globalVars in f.frames:
- stack += f"{filename}:{lineno}:{method}\n"
-
- zde = repr(ZeroDivisionError)
- self.assertTracebackFormat(
- tb,
- f"Traceback: {zde}: ",
- f"{failure.EXCEPTION_CAUGHT_HERE}\n{stack}",
- )
-
- if captureVars:
- self.assertIsNone(re.search("exampleLocalVar.*abcde", tb))
-
- def assertDefaultTraceback(self, captureVars=False):
- """
- Assert that L{printTraceback} produces and prints a default traceback.
-
- The default traceback consists of a header::
-
- Traceback (most recent call last):
-
- The body with traceback::
-
- File "/twisted/trial/_synctest.py", line 1180, in _run
- runWithWarningsSuppressed(suppress, method)
-
- And the footer::
-
- --- <exception caught here> ---
- File "twisted/test/test_failure.py", line 39, in getDivisionFailure
- 1 / 0
- exceptions.ZeroDivisionError: float division
-
- @param captureVars: Enables L{Failure.captureVars}.
- @type captureVars: C{bool}
- """
- if captureVars:
- exampleLocalVar = "xyzzy"
- # Silence the linter as this variable is checked via
- # the traceback.
- exampleLocalVar
-
- f = getDivisionFailure(captureVars=captureVars)
- out = StringIO()
- f.printTraceback(out)
- tb = out.getvalue()
- stack = ""
- for method, filename, lineno, localVars, globalVars in f.frames:
- stack += f' File "{filename}", line {lineno}, in {method}\n'
- stack += f" {linecache.getline(filename, lineno).strip()}\n"
-
- self.assertTracebackFormat(
- tb,
- "Traceback (most recent call last):",
- "%s\n%s%s: %s\n"
- % (
- failure.EXCEPTION_CAUGHT_HERE,
- stack,
- reflect.qual(f.type),
- reflect.safe_str(f.value),
- ),
- )
-
- if captureVars:
- self.assertIsNone(re.search("exampleLocalVar.*xyzzy", tb))
-
- def test_printDetailedTraceback(self):
- """
- L{printDetailedTraceback} returns a detailed traceback including the
- L{Failure}'s count.
- """
- self.assertDetailedTraceback()
-
- def test_printBriefTraceback(self):
- """
- L{printBriefTraceback} returns a brief traceback.
- """
- self.assertBriefTraceback()
-
- def test_printTraceback(self):
- """
- L{printTraceback} returns a traceback.
- """
- self.assertDefaultTraceback()
-
- def test_printDetailedTracebackCapturedVars(self):
- """
- L{printDetailedTraceback} captures the locals and globals for its
- stack frames and adds them to the traceback, when called on a
- L{Failure} constructed with C{captureVars=True}.
- """
- self.assertDetailedTraceback(captureVars=True)
-
- def test_printBriefTracebackCapturedVars(self):
- """
- L{printBriefTraceback} returns a brief traceback when called on a
- L{Failure} constructed with C{captureVars=True}.
-
- Local variables on the stack can not be seen in the resulting
- traceback.
- """
- self.assertBriefTraceback(captureVars=True)
-
- def test_printTracebackCapturedVars(self):
- """
- L{printTraceback} returns a traceback when called on a L{Failure}
- constructed with C{captureVars=True}.
-
- Local variables on the stack can not be seen in the resulting
- traceback.
- """
- self.assertDefaultTraceback(captureVars=True)
-
- def test_printDetailedTracebackCapturedVarsCleaned(self):
- """
- C{printDetailedTraceback} includes information about local variables on
- the stack after C{cleanFailure} has been called.
- """
- self.assertDetailedTraceback(captureVars=True, cleanFailure=True)
-
- def test_invalidFormatFramesDetail(self):
- """
- L{failure.format_frames} raises a L{ValueError} if the supplied
- C{detail} level is unknown.
- """
- self.assertRaises(
- ValueError, failure.format_frames, None, None, detail="noisia"
- )
-
- def test_ExplictPass(self):
- e = RuntimeError()
- f = failure.Failure(e)
- f.trap(RuntimeError)
- self.assertEqual(f.value, e)
-
- def _getInnermostFrameLine(self, f):
- try:
- f.raiseException()
- except ZeroDivisionError:
- tb = traceback.extract_tb(sys.exc_info()[2])
- return tb[-1][-1]
- else:
- raise Exception("f.raiseException() didn't raise ZeroDivisionError!?")
-
- def test_RaiseExceptionWithTB(self):
- f = getDivisionFailure()
- innerline = self._getInnermostFrameLine(f)
- self.assertEqual(innerline, "1 / 0")
-
- def test_stringExceptionConstruction(self):
- """
- Constructing a C{Failure} with a string as its exception value raises
- a C{TypeError}, as this is no longer supported as of Python 2.6.
- """
- exc = self.assertRaises(TypeError, failure.Failure, "ono!")
- self.assertIn("Strings are not supported by Failure", str(exc))
-
- def test_ConstructionFails(self):
- """
- Creating a Failure with no arguments causes it to try to discover the
- current interpreter exception state. If no such state exists, creating
- the Failure should raise a synchronous exception.
- """
- self.assertRaises(failure.NoCurrentExceptionError, failure.Failure)
-
- def test_getTracebackObject(self):
- """
- If the C{Failure} has not been cleaned, then C{getTracebackObject}
- returns the traceback object that captured in its constructor.
- """
- f = getDivisionFailure()
- self.assertEqual(f.getTracebackObject(), f.tb)
-
- def test_getTracebackObjectFromCaptureVars(self):
- """
- C{captureVars=True} has no effect on the result of
- C{getTracebackObject}.
- """
- try:
- 1 / 0
- except ZeroDivisionError:
- noVarsFailure = failure.Failure()
- varsFailure = failure.Failure(captureVars=True)
- self.assertEqual(noVarsFailure.getTracebackObject(), varsFailure.tb)
-
- def test_getTracebackObjectFromClean(self):
- """
- If the Failure has been cleaned, then C{getTracebackObject} returns an
- object that looks the same to L{traceback.extract_tb}.
- """
- f = getDivisionFailure()
- expected = traceback.extract_tb(f.getTracebackObject())
- f.cleanFailure()
- observed = traceback.extract_tb(f.getTracebackObject())
- self.assertIsNotNone(expected)
- self.assertEqual(expected, observed)
-
- def test_getTracebackObjectFromCaptureVarsAndClean(self):
- """
- If the Failure was created with captureVars, then C{getTracebackObject}
- returns an object that looks the same to L{traceback.extract_tb}.
- """
- f = getDivisionFailure(captureVars=True)
- expected = traceback.extract_tb(f.getTracebackObject())
- f.cleanFailure()
- observed = traceback.extract_tb(f.getTracebackObject())
- self.assertEqual(expected, observed)
-
- def test_getTracebackObjectWithoutTraceback(self):
- """
- L{failure.Failure}s need not be constructed with traceback objects. If
- a C{Failure} has no traceback information at all, C{getTracebackObject}
- just returns None.
-
- None is a good value, because traceback.extract_tb(None) -> [].
- """
- f = failure.Failure(Exception("some error"))
- self.assertIsNone(f.getTracebackObject())
-
- def test_tracebackFromExceptionInPython3(self):
- """
- If a L{failure.Failure} is constructed with an exception but no
- traceback in Python 3, the traceback will be extracted from the
- exception's C{__traceback__} attribute.
- """
- try:
- 1 / 0
- except BaseException:
- klass, exception, tb = sys.exc_info()
- f = failure.Failure(exception)
- self.assertIs(f.tb, tb)
-
- def test_cleanFailureRemovesTracebackInPython3(self):
- """
- L{failure.Failure.cleanFailure} sets the C{__traceback__} attribute of
- the exception to L{None} in Python 3.
- """
- f = getDivisionFailure()
- self.assertIsNotNone(f.tb)
- self.assertIs(f.value.__traceback__, f.tb)
- f.cleanFailure()
- self.assertIsNone(f.value.__traceback__)
-
- def test_distb(self):
- """
- The traceback captured by a L{Failure} is compatible with the stdlib
- L{dis.distb} function as used in post-mortem debuggers. Specifically,
- it doesn't cause that function to raise an exception.
- """
- f = getDivisionFailure()
- buf = StringIO()
- distb(f.getTracebackObject(), file=buf)
- # The bytecode details vary across Python versions, so we only check
- # that the arrow pointing at the source of the exception is present.
- self.assertIn(" --> ", buf.getvalue())
-
- def test_repr(self):
- """
- The C{repr} of a L{failure.Failure} shows the type and string
- representation of the underlying exception.
- """
- f = getDivisionFailure()
- typeName = reflect.fullyQualifiedName(ZeroDivisionError)
- self.assertEqual(
- repr(f),
- "<twisted.python.failure.Failure " "%s: division by zero>" % (typeName,),
- )
-
-
- class BrokenStr(Exception):
- """
- An exception class the instances of which cannot be presented as strings
- via L{str}.
- """
-
- def __str__(self) -> str:
- # Could raise something else, but there's no point as yet.
- raise self
-
-
- class BrokenExceptionMetaclass(type):
- """
- A metaclass for an exception type which cannot be presented as a string via
- L{str}.
- """
-
- def __str__(self) -> str:
- raise ValueError("You cannot make a string out of me.")
-
-
- class BrokenExceptionType(Exception, metaclass=BrokenExceptionMetaclass):
-
- """
- The aforementioned exception type which cannot be presented as a string via
- L{str}.
- """
-
-
- class GetTracebackTests(SynchronousTestCase):
- """
- Tests for L{Failure.getTraceback}.
- """
-
- def _brokenValueTest(self, detail):
- """
- Construct a L{Failure} with an exception that raises an exception from
- its C{__str__} method and then call C{getTraceback} with the specified
- detail and verify that it returns a string.
- """
- x = BrokenStr()
- f = failure.Failure(x)
- traceback = f.getTraceback(detail=detail)
- self.assertIsInstance(traceback, str)
-
- def test_brokenValueBriefDetail(self):
- """
- A L{Failure} might wrap an exception with a C{__str__} method which
- raises an exception. In this case, calling C{getTraceback} on the
- failure with the C{"brief"} detail does not raise an exception.
- """
- self._brokenValueTest("brief")
-
- def test_brokenValueDefaultDetail(self):
- """
- Like test_brokenValueBriefDetail, but for the C{"default"} detail case.
- """
- self._brokenValueTest("default")
-
- def test_brokenValueVerboseDetail(self):
- """
- Like test_brokenValueBriefDetail, but for the C{"default"} detail case.
- """
- self._brokenValueTest("verbose")
-
- def _brokenTypeTest(self, detail):
- """
- Construct a L{Failure} with an exception type that raises an exception
- from its C{__str__} method and then call C{getTraceback} with the
- specified detail and verify that it returns a string.
- """
- f = failure.Failure(BrokenExceptionType())
- traceback = f.getTraceback(detail=detail)
- self.assertIsInstance(traceback, str)
-
- def test_brokenTypeBriefDetail(self):
- """
- A L{Failure} might wrap an exception the type object of which has a
- C{__str__} method which raises an exception. In this case, calling
- C{getTraceback} on the failure with the C{"brief"} detail does not raise
- an exception.
- """
- self._brokenTypeTest("brief")
-
- def test_brokenTypeDefaultDetail(self):
- """
- Like test_brokenTypeBriefDetail, but for the C{"default"} detail case.
- """
- self._brokenTypeTest("default")
-
- def test_brokenTypeVerboseDetail(self):
- """
- Like test_brokenTypeBriefDetail, but for the C{"verbose"} detail case.
- """
- self._brokenTypeTest("verbose")
-
-
- class FindFailureTests(SynchronousTestCase):
- """
- Tests for functionality related to L{Failure._findFailure}.
- """
-
- def test_findNoFailureInExceptionHandler(self):
- """
- Within an exception handler, _findFailure should return
- L{None} in case no Failure is associated with the current
- exception.
- """
- try:
- 1 / 0
- except BaseException:
- self.assertIsNone(failure.Failure._findFailure())
- else:
- self.fail("No exception raised from 1/0!?")
-
- def test_findNoFailure(self):
- """
- Outside of an exception handler, _findFailure should return None.
- """
- self.assertIsNone(sys.exc_info()[-1]) # environment sanity check
- self.assertIsNone(failure.Failure._findFailure())
-
- def test_findFailure(self):
- """
- Within an exception handler, it should be possible to find the
- original Failure that caused the current exception (if it was
- caused by raiseException).
- """
- f = getDivisionFailure()
- f.cleanFailure()
- try:
- f.raiseException()
- except BaseException:
- self.assertEqual(failure.Failure._findFailure(), f)
- else:
- self.fail("No exception raised from raiseException!?")
-
- def test_failureConstructionFindsOriginalFailure(self):
- """
- When a Failure is constructed in the context of an exception
- handler that is handling an exception raised by
- raiseException, the new Failure should be chained to that
- original Failure.
- Means the new failure should still show the same origin frame,
- but with different complete stack trace (as not thrown at same place).
- """
- f = getDivisionFailure()
- f.cleanFailure()
- try:
- f.raiseException()
- except BaseException:
- newF = failure.Failure()
- tb = f.getTraceback().splitlines()
- new_tb = newF.getTraceback().splitlines()
- self.assertNotEqual(tb, new_tb)
- self.assertEqual(tb[-3:], new_tb[-3:])
- else:
- self.fail("No exception raised from raiseException!?")
-
- @skipIf(raiser is None, "raiser extension not available")
- def test_failureConstructionWithMungedStackSucceeds(self):
- """
- Pyrex and Cython are known to insert fake stack frames so as to give
- more Python-like tracebacks. These stack frames with empty code objects
- should not break extraction of the exception.
- """
- try:
- raiser.raiseException()
- except raiser.RaiserException:
- f = failure.Failure()
- self.assertTrue(f.check(raiser.RaiserException))
- else:
- self.fail("No exception raised from extension?!")
-
-
- # On Python 3.5, extract_tb returns "FrameSummary" objects, which are almost
- # like the old tuples. This being different does not affect the actual tests
- # as we are testing that the input works, and that extract_tb returns something
- # reasonable.
- def _tb(fn, lineno, name, text):
- return FrameSummary(fn, lineno, name)
-
-
- class FormattableTracebackTests(SynchronousTestCase):
- """
- Whitebox tests that show that L{failure._Traceback} constructs objects that
- can be used by L{traceback.extract_tb}.
-
- If the objects can be used by L{traceback.extract_tb}, then they can be
- formatted using L{traceback.format_tb} and friends.
- """
-
- def test_singleFrame(self):
- """
- A C{_Traceback} object constructed with a single frame should be able
- to be passed to L{traceback.extract_tb}, and we should get a singleton
- list containing a (filename, lineno, methodname, line) tuple.
- """
- tb = failure._Traceback([], [["method", "filename.py", 123, {}, {}]])
- # Note that we don't need to test that extract_tb correctly extracts
- # the line's contents. In this case, since filename.py doesn't exist,
- # it will just use None.
- self.assertEqual(
- traceback.extract_tb(tb), [_tb("filename.py", 123, "method", None)]
- )
-
- def test_manyFrames(self):
- """
- A C{_Traceback} object constructed with multiple frames should be able
- to be passed to L{traceback.extract_tb}, and we should get a list
- containing a tuple for each frame.
- """
- tb = failure._Traceback(
- [
- ["caller1", "filename.py", 7, {}, {}],
- ["caller2", "filename.py", 8, {}, {}],
- ],
- [
- ["method1", "filename.py", 123, {}, {}],
- ["method2", "filename.py", 235, {}, {}],
- ],
- )
- self.assertEqual(
- traceback.extract_tb(tb),
- [
- _tb("filename.py", 123, "method1", None),
- _tb("filename.py", 235, "method2", None),
- ],
- )
-
- # We should also be able to extract_stack on it
- self.assertEqual(
- traceback.extract_stack(tb.tb_frame),
- [
- _tb("filename.py", 7, "caller1", None),
- _tb("filename.py", 8, "caller2", None),
- _tb("filename.py", 123, "method1", None),
- ],
- )
-
-
- class FakeAttributesTests(SynchronousTestCase):
- """
- _Frame, _Code and _TracebackFrame objects should possess some basic
- attributes that qualify them as fake python objects, allowing the return of
- _Traceback to be used as a fake traceback. The attributes that have zero or
- empty values are there so that things expecting them find them (e.g. post
- mortem debuggers).
- """
-
- def test_fakeFrameAttributes(self):
- """
- L{_Frame} instances have the C{f_globals} and C{f_locals} attributes
- bound to C{dict} instance. They also have the C{f_code} attribute
- bound to something like a code object.
- """
- back_frame = failure._Frame(
- (
- "dummyparent",
- "dummyparentfile",
- 111,
- None,
- None,
- ),
- None,
- )
- fake_locals = {"local_var": 42}
- fake_globals = {"global_var": 100}
- frame = failure._Frame(
- (
- "dummyname",
- "dummyfilename",
- 42,
- fake_locals,
- fake_globals,
- ),
- back_frame,
- )
- self.assertEqual(frame.f_globals, fake_globals)
- self.assertEqual(frame.f_locals, fake_locals)
- self.assertIsInstance(frame.f_code, failure._Code)
- self.assertEqual(frame.f_back, back_frame)
- self.assertIsInstance(frame.f_builtins, dict)
- self.assertIsInstance(frame.f_lasti, int)
- self.assertEqual(frame.f_lineno, 42)
- self.assertIsInstance(frame.f_trace, type(None))
-
- def test_fakeCodeAttributes(self):
- """
- See L{FakeAttributesTests} for more details about this test.
- """
- code = failure._Code("dummyname", "dummyfilename")
- self.assertEqual(code.co_name, "dummyname")
- self.assertEqual(code.co_filename, "dummyfilename")
- self.assertIsInstance(code.co_argcount, int)
- self.assertIsInstance(code.co_code, bytes)
- self.assertIsInstance(code.co_cellvars, tuple)
- self.assertIsInstance(code.co_consts, tuple)
- self.assertIsInstance(code.co_firstlineno, int)
- self.assertIsInstance(code.co_flags, int)
- self.assertIsInstance(code.co_lnotab, bytes)
- self.assertIsInstance(code.co_freevars, tuple)
- self.assertIsInstance(code.co_posonlyargcount, int)
- self.assertIsInstance(code.co_kwonlyargcount, int)
- self.assertIsInstance(code.co_names, tuple)
- self.assertIsInstance(code.co_nlocals, int)
- self.assertIsInstance(code.co_stacksize, int)
- self.assertIsInstance(code.co_varnames, list)
- self.assertIsInstance(code.co_positions(), tuple)
-
- def test_fakeTracebackFrame(self):
- """
- See L{FakeAttributesTests} for more details about this test.
- """
- frame = failure._Frame(
- ("dummyname", "dummyfilename", 42, {}, {}),
- None,
- )
- traceback_frame = failure._TracebackFrame(frame)
- self.assertEqual(traceback_frame.tb_frame, frame)
- self.assertEqual(traceback_frame.tb_lineno, 42)
- self.assertIsInstance(traceback_frame.tb_lasti, int)
- self.assertTrue(hasattr(traceback_frame, "tb_next"))
-
-
- class DebugModeTests(SynchronousTestCase):
- """
- Failure's debug mode should allow jumping into the debugger.
- """
-
- def setUp(self):
- """
- Override pdb.post_mortem so we can make sure it's called.
- """
- # Make sure any changes we make are reversed:
- post_mortem = pdb.post_mortem
- origInit = failure.Failure.__init__
-
- def restore():
- pdb.post_mortem = post_mortem
- failure.Failure.__init__ = origInit
-
- self.addCleanup(restore)
-
- self.result = []
- pdb.post_mortem = self.result.append
- failure.startDebugMode()
-
- def test_regularFailure(self):
- """
- If startDebugMode() is called, calling Failure() will first call
- pdb.post_mortem with the traceback.
- """
- try:
- 1 / 0
- except BaseException:
- typ, exc, tb = sys.exc_info()
- f = failure.Failure()
- self.assertEqual(self.result, [tb])
- self.assertFalse(f.captureVars)
-
- def test_captureVars(self):
- """
- If startDebugMode() is called, passing captureVars to Failure() will
- not blow up.
- """
- try:
- 1 / 0
- except BaseException:
- typ, exc, tb = sys.exc_info()
- f = failure.Failure(captureVars=True)
- self.assertEqual(self.result, [tb])
- self.assertTrue(f.captureVars)
-
-
- class ExtendedGeneratorTests(SynchronousTestCase):
- """
- Tests C{failure.Failure} support for generator features added in Python 2.5
- """
-
- def _throwIntoGenerator(self, f, g):
- try:
- f.throwExceptionIntoGenerator(g)
- except StopIteration:
- pass
- else:
- self.fail("throwExceptionIntoGenerator should have raised " "StopIteration")
-
- def test_throwExceptionIntoGenerator(self):
- """
- It should be possible to throw the exception that a Failure
- represents into a generator.
- """
- stuff = []
-
- def generator():
- try:
- yield
- except BaseException:
- stuff.append(sys.exc_info())
- else:
- self.fail("Yield should have yielded exception.")
-
- g = generator()
- f = getDivisionFailure()
- next(g)
- self._throwIntoGenerator(f, g)
-
- self.assertEqual(stuff[0][0], ZeroDivisionError)
- self.assertIsInstance(stuff[0][1], ZeroDivisionError)
-
- self.assertEqual(traceback.extract_tb(stuff[0][2])[-1][-1], "1 / 0")
-
- def test_findFailureInGenerator(self):
- """
- Within an exception handler, it should be possible to find the
- original Failure that caused the current exception (if it was
- caused by throwExceptionIntoGenerator).
- """
- f = getDivisionFailure()
- f.cleanFailure()
- foundFailures = []
-
- def generator():
- try:
- yield
- except BaseException:
- foundFailures.append(failure.Failure._findFailure())
- else:
- self.fail("No exception sent to generator")
-
- g = generator()
- next(g)
- self._throwIntoGenerator(f, g)
-
- self.assertEqual(foundFailures, [f])
-
- def test_failureConstructionFindsOriginalFailure(self):
- """
- When a Failure is constructed in the context of an exception
- handler that is handling an exception raised by
- throwExceptionIntoGenerator, the new Failure should be chained to that
- original Failure.
- """
- f = getDivisionFailure()
- f.cleanFailure()
- original_failure_str = f.getTraceback()
-
- newFailures = []
-
- def generator():
- try:
- yield
- except BaseException:
- newFailures.append(failure.Failure())
- else:
- self.fail("No exception sent to generator")
-
- g = generator()
- next(g)
- self._throwIntoGenerator(f, g)
-
- self.assertEqual(len(newFailures), 1)
-
- # The original failure should not be changed.
- self.assertEqual(original_failure_str, f.getTraceback())
-
- # The new failure should be different and contain stack info for
- # our generator.
- self.assertNotEqual(newFailures[0].getTraceback(), f.getTraceback())
- self.assertIn("generator", newFailures[0].getTraceback())
- self.assertNotIn("generator", f.getTraceback())
-
- def test_ambiguousFailureInGenerator(self):
- """
- When a generator reraises a different exception,
- L{Failure._findFailure} inside the generator should find the reraised
- exception rather than original one.
- """
-
- def generator():
- try:
- try:
- yield
- except BaseException:
- [][1]
- except BaseException:
- self.assertIsInstance(failure.Failure().value, IndexError)
-
- g = generator()
- next(g)
- f = getDivisionFailure()
- self._throwIntoGenerator(f, g)
-
- def test_ambiguousFailureFromGenerator(self):
- """
- When a generator reraises a different exception,
- L{Failure._findFailure} above the generator should find the reraised
- exception rather than original one.
- """
-
- def generator():
- try:
- yield
- except BaseException:
- [][1]
-
- g = generator()
- next(g)
- f = getDivisionFailure()
- try:
- self._throwIntoGenerator(f, g)
- except BaseException:
- self.assertIsInstance(failure.Failure().value, IndexError)
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