Without this if a session scoped fixture fails it's setup it will
be re-tried each time it is requested. Especially in case of
skip or failure exceptions this can be undesirable, but caching
makes sense for all exceptions.
If the type is not checked then an incomprehensible error will occur
later. This enforces the type and raies the same exception/msg as
CPython does in that case.
Docstring unmodified, just re-justified for pep8 compat.
Such reference cycles unnecessarily cause Python interpreter not to garbage
collect the objects referenced in those cycles as soon they could be collected,
and in turn cause the tests to use more memory than is strictly necessary.
--HG--
branch : break_ExceptionInfo_reference_cycles
use the original stream.
- avoid resetting capture FDs/sys.stdout for each test by keeping capturing
always turned on and looking at snapshotted capturing data during runtest
and collection phases.
Made it clearer that clearing such references is not mandatory and is only an
optional step which may help the Python interpreter speed up its garbage
collection.
--HG--
branch : document_ExceptionInfo_ref_cycle
pytest.raises() returns an ExceptionInfo object which, if a local reference is
made to it, forms a reference cycle:
ExceptionInfo
--> exception
--> stack frame raising the exception
--> current stack frame
--> current local variables
--> Exception Info
Such a reference cycle would then prevent any local variables in the current
stack frame, or any of its child stack frames involved in the same reference
cycle, from being garbage collected until the next reference cycle garbage
collection phase. This unnecessarily increases the program's memory footprint
and potentially slows it down.
This situation is based on a similar one described in the official 'try'
statement Python documentation for locally stored exception references.
--HG--
branch : document_ExceptionInfo_ref_cycle
The only remaining 'py.test' references are:
* those referring to the 'py.test' executable
* those in code explicitly testing py.test/pytest module compatibility
* those in old CHANGES documentation
* those in documentation generated based on external data
* those in seemingly unfinished & unmaintained Japanese documentation
Minor stylistic changes and typo corrections made to documentation next to
several applied py.test --> pytest content changes.
The need for comparing two separately instantiated nodes seems to be historic
(related to an already-gone mode of pytest-xdist which would re-collect nodes)
and not actually needed anymore.
in a test invocation will have a corresponding FixtureDef instance.
also fixes issue246 (again).
simplify parametrized fixture teardown by making it work lazy:
during the setup of a parametrized fixture instance any previously
setup instance which was setup with a different param is torn down
before setting up the new one.