Opened 7 years ago
Closed 6 years ago
#29024 closed Bug (fixed)
`TestContextDecorator` never exits if `setUp` fails in tests
Reported by: | Anthony King | Owned by: | Kamil |
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Component: | Testing framework | Version: | dev |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Accepted | |
Has patch: | yes | Needs documentation: | no |
Needs tests: | yes | Patch needs improvement: | yes |
Easy pickings: | yes | UI/UX: | no |
Description (last modified by )
when using TestContextDecorator
as a class decorator, enable
is called just before Test.setUp
, and disable
is called after Test.tearDown
.
unfortunately, tearDown
is not called in the event of a failure inside setUp
. This can result in unexpected behaviour.
Even though this class is not documented, there are decorators that use it that are.
example:
class example_decorator(TestContextDecorator): some_var = False def enable(self): self.__class__.some_var = True def disable(self): self.__class__.some_var = False class Example1TestCase(TestCase): def test_var_is_false(self): # some_var will be False self.assertFalse(example_decorator.some_var) @example_decorator() class Example2TestCase(TestCase): def setUp(self): raise Exception def test_var_is_true(self): # won't be hit due to exception in setUp self.assertTrue(example_decorator.some_var) class Example3TestCase(TestCase): def test_var_is_false(self): # some_var will be True now due to no cleanup in Example2TestCase self.assertFalse(example_decorator.some_var)
output:
.EF ====================================================================== ERROR: test_var_is_true (example.tests.Example2TestCase) ---------------------------------------------------------------------- ... Traceback ====================================================================== FAIL: test_var_is_false (example.tests.Example3TestCase) ---------------------------------------------------------------------- ... AssertionError: True is not false Ran 3 tests in 0.007s FAILED (failures=1, errors=1)
There are 2 potential fixes here:
- decorate
setUpClass
andtearDownClass
- use
addCleanup
inside thesetUp
decorator
addCleanup
will always run, and will only ever be registered if the context manager was successfully enabled.
It would also be useful to have this class documented, however that's out of scope of this ticket.
Change History (10)
comment:1 by , 7 years ago
Triage Stage: | Unreviewed → Accepted |
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Version: | 1.11 → master |
comment:2 by , 7 years ago
Owner: | changed from | to
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Status: | new → assigned |
comment:3 by , 7 years ago
Description: | modified (diff) |
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comment:4 by , 7 years ago
Hi Shahbaj,
I saw your post in the mailing list.
So how we've done it internally is like this:
class TestContextDecorator(DjangoTestContextDecorator): def decorate_class(self, cls): # https://code.djangoproject.com/ticket/29024 if issubclass(cls, TestCase): decorated_setUp = cls.setUp @wraps(decorated_setUp) def setUp(inner_self): context = self.enable() if self.attr_name: setattr(inner_self, self.attr_name, context) inner_self.addCleanup(self.disable) decorated_setUp(inner_self) cls.setUp = setUp return cls raise TypeError('Can only decorate subclasses of unittest.TestCase')
comment:6 by , 7 years ago
Needs tests: | set |
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comment:7 by , 6 years ago
Owner: | removed |
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Status: | assigned → new |
comment:8 by , 6 years ago
Owner: | set to |
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Status: | new → assigned |
Using
addCleanup
instead of hooking up ontearDown
makes sense here.