twisted.test.test_failure.FailureTests

class documentation

class FailureTests(SynchronousTestCase): (source)

Tests for failure.Failure.

Method	`assertBriefTraceback`	Assert that `printBriefTraceback` produces and prints a brief traceback.
Method	`assertDefaultTraceback`	Assert that `printTraceback` produces and prints a default traceback.
Method	`assertDetailedTraceback`	Assert that `printDetailedTraceback` produces and prints a detailed traceback.
Method	`assertEndsWith`	Assert that `s` end with a particular `suffix`.
Method	`assertStartsWith`	Assert that `s` starts with a particular `prefix`.
Method	`assertTracebackFormat`	Assert that the `tb` traceback contains a particular `prefix` and `suffix`.
Method	`test_cleanFailureRemovesTracebackInPython3`	`failure.Failure.cleanFailure` sets the `__traceback__` attribute of the exception to `None` in Python 3.
Method	`test_ConstructionFails`	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.
Method	`test_distb`	The traceback captured by a `Failure` is compatible with the stdlib `dis.distb` function as used in post-mortem debuggers. Specifically, it doesn't cause that function to raise an exception.
Method	`test_ExplictPass`	Undocumented
Method	`test_failAndTrap`	Trapping a `Failure`.
Method	`test_failureValueFromFailure`	A `failure.Failure` constructed from another `failure.Failure` instance, has its `value` property set to the value of that `failure.Failure` instance.
Method	`test_failureValueFromFoundFailure`	A `failure.Failure` constructed without a `exc_value` argument, will search for an "original" `Failure`, and if found, its value will be used as the value for the new `Failure`.
Method	`test_getTracebackObject`	If the `Failure` has not been cleaned, then `getTracebackObject` returns the traceback object that captured in its constructor.
Method	`test_getTracebackObjectFromCaptureVars`	`captureVars=True` has no effect on the result of `getTracebackObject`.
Method	`test_getTracebackObjectFromCaptureVarsAndClean`	If the Failure was created with captureVars, then `getTracebackObject` returns an object that looks the same to `traceback.extract_tb`.
Method	`test_getTracebackObjectFromClean`	If the Failure has been cleaned, then `getTracebackObject` returns an object that looks the same to `traceback.extract_tb`.
Method	`test_getTracebackObjectWithoutTraceback`	`failure.Failure`s need not be constructed with traceback objects. If a `Failure` has no traceback information at all, `getTracebackObject` just returns None.
Method	`test_invalidFormatFramesDetail`	`failure.format_frames` raises a `ValueError` if the supplied `detail` level is unknown.
Method	`test_printBriefTraceback`	`printBriefTraceback` returns a brief traceback.
Method	`test_printBriefTracebackCapturedVars`	`printBriefTraceback` returns a brief traceback when called on a `Failure` constructed with `captureVars=True`.
Method	`test_printDetailedTraceback`	`printDetailedTraceback` returns a detailed traceback including the `Failure`'s count.
Method	`test_printDetailedTracebackCapturedVars`	`printDetailedTraceback` captures the locals and globals for its stack frames and adds them to the traceback, when called on a `Failure` constructed with `captureVars=True`.
Method	`test_printDetailedTracebackCapturedVarsCleaned`	`printDetailedTraceback` includes information about local variables on the stack after `cleanFailure` has been called.
Method	`test_printTraceback`	`printTraceback` returns a traceback.
Method	`test_printTracebackCapturedVars`	`printTraceback` returns a traceback when called on a `Failure` constructed with `captureVars=True`.
Method	`test_RaiseExceptionWithTB`	Undocumented
Method	`test_repr`	The `repr` of a `failure.Failure` shows the type and string representation of the underlying exception.
Method	`test_stringExceptionConstruction`	Constructing a `Failure` with a string as its exception value raises a `TypeError`, as this is no longer supported as of Python 2.6.
Method	`test_tracebackFromExceptionInPython3`	If a `failure.Failure` is constructed with an exception but no traceback in Python 3, the traceback will be extracted from the exception's `__traceback__` attribute.
Method	`test_trapRaisesWrappedException`	If the wrapped `Exception` is not a subclass of one of the expected types, `failure.Failure.trap` raises the wrapped `Exception`.
Method	`_getInnermostFrameLine`	Undocumented

Inherited from SynchronousTestCase:

Method	`__eq__`	Override the comparison defined by the base TestCase which considers instances of the same class with the same _testMethodName to be equal. Since trial puts TestCase instances into a set, that definition of comparison makes it impossible to run the same test method twice...
Method	`__hash__`	Undocumented
Method	`__init__`	Undocumented
Method	`addCleanup`	Add the given function to a list of functions to be called after the test has run, but before `tearDown`.
Method	`callDeprecated`	Call a function that should have been deprecated at a specific version and in favor of a specific alternative, and assert that it was thusly deprecated.
Method	`flushLoggedErrors`	Remove stored errors received from the log.
Method	`flushWarnings`	Remove stored warnings from the list of captured warnings and return them.
Method	`getDeprecatedModuleAttribute`	Retrieve a module attribute which should have been deprecated, and assert that we saw the appropriate deprecation warning.
Method	`getSkip`	Return the skip reason set on this test, if any is set. Checks on the instance first, then the class, then the module, then packages. As soon as it finds something with a `skip` attribute, returns that in a tuple (...
Method	`getTodo`	Return a `Todo` object if the test is marked todo. Checks on the instance first, then the class, then the module, then packages. As soon as it finds something with a `todo` attribute, returns that. Returns ...
Method	`mktemp`	Create a new path name which can be used for a new file or directory.
Method	`patch`	Monkey patch an object for the duration of the test.
Method	`run`	Run the test case, storing the results in `result`.
Method	`runTest`	If no `methodName` argument is passed to the constructor, `run` will treat this method as the thing with the actual test inside.
Method	`shortDescription`	Undocumented
Instance Variable	`failureException`	An exception class, defaulting to `FailTest`. If the test method raises this exception, it will be reported as a failure, rather than an exception. All of the assertion methods raise this if the assertion fails.
Instance Variable	`skip`	`None` or a string explaining why this test is to be skipped. If defined, the test will not be run. Instead, it will be reported to the result object as 'skipped' (if the `TestResult` supports skipping).
Instance Variable	`suppress`	`None` or a list of tuples of `(args, kwargs)` to be passed to `warnings.filterwarnings`. Use these to suppress warnings raised in a test. Useful for testing deprecated code. See also `util.suppress`.
Instance Variable	`todo`	`None`, a string or a tuple of `(errors, reason)` where `errors` is either an exception class or an iterable of exception classes, and `reason` is a string. See `Todo` or `makeTodo` for more information.
Method	`_getSkipReason`	Return the reason to use for skipping a test method.
Method	`_getSuppress`	Returns any warning suppressions set for this test. Checks on the instance first, then the class, then the module, then packages. As soon as it finds something with a `suppress` attribute, returns that. ...
Method	`_installObserver`	Undocumented
Method	`_removeObserver`	Undocumented
Method	`_run`	Run a single method, either a test method or fixture.
Method	`_runCleanups`	Synchronously run any cleanups which have been added.
Method	`_runFixturesAndTest`	Run `setUp`, a test method, test cleanups, and `tearDown`.
Instance Variable	`_cleanups`	Undocumented
Instance Variable	`_observer`	Undocumented
Instance Variable	`_parents`	Undocumented
Instance Variable	`_passed`	Undocumented
Instance Variable	`_testMethodName`	Undocumented
Instance Variable	`_warnings`	Undocumented

Inherited from _Assertions (via SynchronousTestCase):

Method	`assertAlmostEqual`	Fail if the two objects are unequal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero.
Method	`assertApproximates`	Fail if `first` - `second` > `tolerance`
Method	`assertEqual`	Fail the test if `first` and `second` are not equal.
Method	`assertFalse`	Fail the test if `condition` evaluates to True.
Method	`assertIn`	Fail the test if `containee` is not found in `container`.
Method	`assertIs`	Fail the test if `first` is not `second`. This is an obect-identity-equality test, not an object equality (i.e. `__eq__`) test.
Method	`assertIsInstance`	Fail if `instance` is not an instance of the given class or of one of the given classes.
Method	`assertIsNot`	Fail the test if `first` is `second`. This is an obect-identity-equality test, not an object equality (i.e. `__eq__`) test.
Method	`assertNoResult`	Assert that `deferred` does not have a result at this point.
Method	`assertNotAlmostEqual`	Fail if the two objects are equal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero.
Method	`assertNotEqual`	Fail the test if `first` == `second`.
Method	`assertNotIn`	Fail the test if `containee` is found in `container`.
Method	`assertNotIsInstance`	Fail if `instance` is an instance of the given class or of one of the given classes.
Method	`assertNotSubstring`	Fail if `astring` contains `substring`.
Method	`assertRaises`	Fail the test unless calling the function `f` with the given `args` and `kwargs` raises `exception`. The failure will report the traceback and call stack of the unexpected exception.
Method	`assertSubstring`	Fail if `substring` does not exist within `astring`.
Method	`assertTrue`	Fail the test if `condition` evaluates to False.
Method	`assertWarns`	Fail if the given function doesn't generate the specified warning when called. It calls the function, checks the warning, and forwards the result of the function if everything is fine.
Method	`fail`	Absolutely fail the test. Do not pass go, do not collect $200.
Method	`failureResultOf`	Return the current failure result of `deferred` or raise `self.failureException`.
Method	`successResultOf`	Return the current success result of `deferred` or raise `self.failureException`.

def assertBriefTraceback(self, captureVars=False): (source) ¶

Assert that 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

Parameters
captureVars:`bool`	Enables `Failure.captureVars`.

def assertDefaultTraceback(self, captureVars=False): (source) ¶

Assert that 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

Parameters
captureVars:`bool`	Enables `Failure.captureVars`.

def assertDetailedTraceback(self, captureVars=False, cleanFailure=False): (source) ¶

Assert that 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 captureVars is enabled the body also includes a list of globals and locals:

   [ Locals ]
     exampleLocalVar : 'xyz'
     ...
   ( Globals )
     ...

Or when captureVars is disabled:

   [Capture of Locals and Globals disabled (use captureVars=True)]

When cleanFailure is enabled references to other objects are removed and replaced with strings.

And finally the footer with the Failure's value:

  exceptions.ZeroDivisionError: float division
  *--- End of Failure #20 ---

Parameters
captureVars:`bool`	Enables `Failure.captureVars`.
cleanFailure:`bool`	Enables `Failure.cleanFailure`.

def assertEndsWith(self, s, suffix): (source) ¶

Assert that s end with a particular suffix.

Parameters
s:`str`	The input string.
suffix:`str`	The string that `s` should end with.

def assertStartsWith(self, s, prefix): (source) ¶

Assert that s starts with a particular prefix.

Parameters
s:`str`	The input string.
prefix:`str`	The string that `s` should start with.

def assertTracebackFormat(self, tb, prefix, suffix): (source) ¶

Assert that the tb traceback contains a particular prefix and suffix.

Parameters
tb:`str`	The traceback string.
prefix:`str`	The string that `tb` should start with.
suffix:`str`	The string that `tb` should end with.

def test_cleanFailureRemovesTracebackInPython3(self): (source) ¶

failure.Failure.cleanFailure sets the __traceback__ attribute of the exception to None in Python 3.

def test_ConstructionFails(self): (source) ¶

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.

def test_distb(self): (source) ¶

The traceback captured by a Failure is compatible with the stdlib dis.distb function as used in post-mortem debuggers. Specifically, it doesn't cause that function to raise an exception.

def test_ExplictPass(self): (source) ¶

Undocumented

def test_failAndTrap(self): (source) ¶

Trapping a Failure.

def test_failureValueFromFailure(self): (source) ¶

A failure.Failure constructed from another failure.Failure instance, has its value property set to the value of that failure.Failure instance.

def test_failureValueFromFoundFailure(self): (source) ¶

A failure.Failure constructed without a exc_value argument, will search for an "original" Failure, and if found, its value will be used as the value for the new Failure.

def test_getTracebackObject(self): (source) ¶

If the Failure has not been cleaned, then getTracebackObject returns the traceback object that captured in its constructor.

def test_getTracebackObjectFromCaptureVars(self): (source) ¶

captureVars=True has no effect on the result of getTracebackObject.

def test_getTracebackObjectFromCaptureVarsAndClean(self): (source) ¶

If the Failure was created with captureVars, then getTracebackObject returns an object that looks the same to traceback.extract_tb.

def test_getTracebackObjectFromClean(self): (source) ¶

If the Failure has been cleaned, then getTracebackObject returns an object that looks the same to traceback.extract_tb.

def test_getTracebackObjectWithoutTraceback(self): (source) ¶

failure.Failures need not be constructed with traceback objects. If a Failure has no traceback information at all, getTracebackObject just returns None.

None is a good value, because traceback.extract_tb(None) -> [].

def test_invalidFormatFramesDetail(self): (source) ¶

failure.format_frames raises a ValueError if the supplied detail level is unknown.

def test_printBriefTraceback(self): (source) ¶

printBriefTraceback returns a brief traceback.

def test_printBriefTracebackCapturedVars(self): (source) ¶

printBriefTraceback returns a brief traceback when called on a Failure constructed with captureVars=True.

Local variables on the stack can not be seen in the resulting traceback.

def test_printDetailedTraceback(self): (source) ¶

printDetailedTraceback returns a detailed traceback including the Failure's count.

def test_printDetailedTracebackCapturedVars(self): (source) ¶

printDetailedTraceback captures the locals and globals for its stack frames and adds them to the traceback, when called on a Failure constructed with captureVars=True.

def test_printDetailedTracebackCapturedVarsCleaned(self): (source) ¶

printDetailedTraceback includes information about local variables on the stack after cleanFailure has been called.

def test_printTraceback(self): (source) ¶

printTraceback returns a traceback.

def test_printTracebackCapturedVars(self): (source) ¶

printTraceback returns a traceback when called on a Failure constructed with captureVars=True.

Local variables on the stack can not be seen in the resulting traceback.

def test_RaiseExceptionWithTB(self): (source) ¶

Undocumented

def test_repr(self): (source) ¶

The repr of a failure.Failure shows the type and string representation of the underlying exception.

def test_stringExceptionConstruction(self): (source) ¶

Constructing a Failure with a string as its exception value raises a TypeError, as this is no longer supported as of Python 2.6.

def test_tracebackFromExceptionInPython3(self): (source) ¶

If a failure.Failure is constructed with an exception but no traceback in Python 3, the traceback will be extracted from the exception's __traceback__ attribute.

def test_trapRaisesWrappedException(self): (source) ¶

If the wrapped Exception is not a subclass of one of the expected types, failure.Failure.trap raises the wrapped Exception.

def _getInnermostFrameLine(self, f): (source) ¶

Undocumented