[pytest-dev] pytest-xdist-1.11: restarting crash nodes, fixture cache fix

[holger krekel]

On Thu, Sep 18, 2014 at 20:35 +0200, Anatoly Bubenkov wrote:
> yes per testing subprocess, as i've already asked in the comments section
> on the paylogic developer portal, im waiting for your confirmation that's
> NOT by design that we were getting multiple test sessions per test
> subprocess
> so i'll need to fix the article then

yes, it's not by design.  It was more an implementation incident.

> BTW: now im reading the code again, it looks like even with randomization
> plugin it should not matter?

pytest relies on the following property of test collections: if a test
at index I1 uses a session-scoped fixture X and at an index I2>I1 X is not
used than for any I3>I2 X will not be used, either.  If this is not
true for any given testing process then the fixture will be torn down
and setup again (at I3).  pytest groups tests so in general this property
is true (see here:
https://pytest.org/latest/fixture.html#automatic-grouping-of-tests-by-fixture-instances for how it groups).

If you have multiple parametrized session-scoped fixtures (not very common)
or item randomization the above property is likely not true but that already
is true then for single-process execution.

best,
holger

> On 18 September 2014 20:31, holger krekel <holger at merlinux.eu> wrote:
> 
> > On Thu, Sep 18, 2014 at 20:24 +0200, Anatoly Bubenkov wrote:
> > > so, this is again guaranteed that there will be only one session per test
> > > run on any test slave?
> >
> > there is always one session object only but i think you are asking if a
> > session-scoped fixture will only be instantiated once per testing
> > subprocess, right?  In general this should be the case if i am not missing
> > something (when you use a test randomization plugin, then it's probably
> > not the case).
> >
> > best,
> > holger
> >
> > > On 18 September 2014 20:23, Anatoly Bubenkov <bubenkoff at gmail.com>
> > wrote:
> > >
> > > > Great!
> > > > thanks a lot everyone involved
> > > >
> > > > On 18 September 2014 20:21, holger krekel <holger at merlinux.eu> wrote:
> > > >
> > > >>
> > > >> I just released pytest-xdist-1.11, the distributed testing plugin for
> > > >> pytest.
> > > >> It introduces automatic restarting of crashed nodes, courtesy of a
> > > >> complete PR from Floris Bruynooghe.  This also works well together
> > with
> > > >> pytest-timeout by the same author: When one or more test functions
> > hang
> > > >> or crash, the overall test run will still complete and report about
> > the
> > > >> incidents.  See the changelog below for more changes and the pypi
> > > >> project page for what pytest-xdist offers in general:
> > > >>
> > > >>     https://pypi.python.org/pypi/pytest-xdist/
> > > >>
> > > >> Thanks also to an undisclosed company who partly funded the work
> > > >> and to Andreas Pelme for contributing analysis of a fixture caching
> > > >> failure including a test.
> > > >>
> > > >> best,
> > > >> Holger Krekel
> > > >>
> > > >>
> > > >> 1.11
> > > >> -------------------------
> > > >>
> > > >> - fix pytest/xdist issue485 (also depends on py-1.4.22):
> > > >>   attach stdout/stderr on --boxed processes that die.
> > > >>
> > > >> - fix pytest/xdist issue503: make sure that a node has usually
> > > >>   two items to execute to avoid scoped fixtures to be torn down
> > > >>   pre-maturely (fixture teardown/setup is "nextitem" sensitive).
> > > >>   Thanks to Andreas Pelme for bug analysis and failing test.
> > > >>
> > > >> - restart crashed nodes by internally refactoring setup handling
> > > >>   of nodes.  Also includes better code documentation.
> > > >>   Many thanks to Floris Bruynooghe for the complete PR.
> > > >>
> > > >> _______________________________________________
> > > >> Pytest-dev mailing list
> > > >> Pytest-dev at python.org
> > > >> https://mail.python.org/mailman/listinfo/pytest-dev
> > > >>
> > > >
> > > >
> > > >
> > > > --
> > > > Anatoly Bubenkov
> > > >
> > >
> > >
> > >
> > > --
> > > Anatoly Bubenkov
> >
> 
> 
> 
> -- 
> Anatoly Bubenkov