Preparse sage files before passing them to pytest #33550
Description
We fix
$ ./sage -tp src/sage/tests/cmdline.py
too many failed tests, not using stored timings
Running doctests with ID 2022-03-20-11-46-21-1dc8fb11.
Using --optional=4ti2,buckygen,ccache,cryptominisat,debugpy,e_antic,gap_packages,homebrew,igraph,jupymake,latte_int,libsemigroups,lidia,lrslib,meataxe,normaliz,pip,polytopes_db_4d,pynormaliz,sage,sage_spkg,texttable
Features to be detected: 4ti2,benzene,bliss,buckygen,conway_polynomials,csdp,database_cremona_ellcurve,database_cremona_mini_ellcurve,database_jones_numfield,database_knotinfo,dvipng,graphviz,imagemagick,jupymake,kenzo,latte_int,lrslib,mcqd,meataxe,nauty,palp,pandoc,pdf2svg,pdftocairo,plantri,polytopes_db,polytopes_db_4d,pynormaliz,python_igraph,rubiks,sage.combinat,sage.geometry.polyhedron,sage.graphs,sage.groups,sage.plot,sage.rings.number_field,sage.rings.padics,sage.rings.real_double,sage.symbolic,sage_numerical_backends_coin,sagemath_doc_html,sphinx,tdlib
Doctesting 1 file using 8 threads.
sage -t --random-seed=23402257756506608859254049173870803147 src/sage/tests/cmdline.py
**********************************************************************
File "src/sage/tests/cmdline.py", line 312, in sage.tests.cmdline.test_executable
Failed example:
ret
Expected:
0
Got:
4
As analyzed in #33531 comment:9, this is due to pytest running on the temporary file my_script.sage and failing with
=================================================================== test session starts ===================================================================
platform linux -- Python 3.10.2, pytest-7.0.1, pluggy-1.0.0
rootdir: /home/fbissey
plugins: hypothesis-6.38.0
collected 0 items
================================================================== no tests ran in 0.00s ==================================================================
ERROR: not found: /home/fbissey/.sage/temp/tarazed/1679924/dir_v9uzl0t4/my_script.sage
(no name '/home/fbissey/.sage/temp/tarazed/1679924/dir_v9uzl0t4/my_script.sage' in any of [])
In other words, pytest doesn't know how to analyze .sage files. We fix this by letting pytest know that .sage files are essentially normal python files after they run through the preparser (this is accomplished by implementing an importlib.Loader for .sage files, which is then used by pytest).
Sadly, this doesn't completely fix the issue and the above test in cmdline still fails. However, the error is now
ERROR: not found: /home/tobias/.sage/temp/DESKTOP-MRB66LP/15784/dir_5qrixjen/my_script.sage
(no name '/home/tobias/.sage/temp/DESKTOP-MRB66LP/15784/dir_5qrixjen/my_script.sage' in any of [])
which comes from some issues of pytesting files outside of the sage source directory. In fact, running sage -t on a copy of the offending file somewhere in /src works.
CC: @mkoeppe @tornaria @kiwifb
Component: doctest framework
Author: Tobias Diez
Branch/Commit: public/tests/pytest_sage_files @ 24a0b17
Issue created by migration from https://trac.sagemath.org/ticket/33550