Error when testing dialect with an exclusion

[sqlalchemy-bot]

Migrated issue, originally created by Patrick Buxton

The error shown below is seen when testing a dialect with:

    @property
    def json_type(self):
        return exclusions.closed()

=================================== ERRORS ====================================
___________ ERROR at setup of JSONTest.test_crit_against_int_basic ____________
Traceback (most recent call last):
  File "C:\Users\pat\Anaconda2\lib\site-packages\sqlalchemy\testing\plugin\pytestplugin.py", line 173, in pytest_runtest_setup
    class_setup(item.parent.parent)
  File "C:\Users\pat\Anaconda2\lib\site-packages\sqlalchemy\testing\plugin\pytestplugin.py", line 206, in class_setup
    plugin_base.start_test_class(item.cls)
  File "C:\Users\pat\Anaconda2\lib\site-packages\sqlalchemy\testing\plugin\plugin_base.py", line 452, in start_test_class
    _do_skips(cls)
  File "C:\Users\pat\Anaconda2\lib\site-packages\sqlalchemy\testing\plugin\plugin_base.py", line 567, in _do_skips
    for config_obj in config.Config.all_configs()
  File "C:\Users\pat\Anaconda2\lib\site-packages\sqlalchemy\testing\plugin\plugin_base.py", line 567, in <genexpr>
    for config_obj in config.Config.all_configs()
TypeError: 'NoneType' object is not iterable

I'm working on two dialects with this skip in place and it doesn't affect one of them, but I have seen that other people have also had this issue. (MonetDB/sqlalchemy-monetdb#30)

The easiest way to reproduce will be to run the dialect tests:

git clone git@github.com:PlaidCloud/sqlalchemy-hana.git
cd sqlalchemy-hana
git checkout identity_column
python setup.py test

Just comment out line 62 in testing\provision.py if you don't have a HANA server to point at and you'll still get the error generated even if the tests fail.

[sqlalchemy-bot]

Changes by Patrick Buxton:

• edited description

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

your setup.py seems to be defaulting to python unittest, which is not supported, on both Python 2 and Python 3 I get essentially this error:

ImportError: Failed to import test module: test.test_suite
Traceback (most recent call last):
  File "/usr/lib64/python2.7/unittest/loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "/usr/lib64/python2.7/unittest/loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "/home/classic/dev/sqlalchemy-hana/test/test_suite.py", line 19, in <module>
    from sqlalchemy.testing.suite import *
  File "build/bdist.linux-x86_64/egg/sqlalchemy/testing/suite/__init__.py", line 2, in <module>
  File "build/bdist.linux-x86_64/egg/sqlalchemy/testing/suite/test_dialect.py", line 11, in <module>
  File "build/bdist.linux-x86_64/egg/sqlalchemy/testing/suite/test_dialect.py", line 29, in ExceptionTest
AttributeError: 'NoneType' object has no attribute 'duplicate_key_raises_integrity_error'

can't run with py.test because you don't have a [db] section in your setup.cfg. The test suite should be set up as documented at: https://github.com/zzzeek/sqlalchemy/blob/master/README.unittests.rst

I tried putting a standalone @Property in a local test/reqriements.py like you have above and no error is generated, it skips the JSON tests as expected.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

oh sorry, I meant: https://github.com/zzzeek/sqlalchemy/blob/master/README.dialects.rst

[sqlalchemy-bot]

Patrick Buxton wrote:

Apologies, I gave you incorrect info. Once the repo is cloned, please git checkout the identity_column branch where I had made the changes to the setup.cfg
Hopefully you'll then see the error I'm getting.

[sqlalchemy-bot]

Changes by Patrick Buxton:

• edited description

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

still cant reproduce anything, I can change the URL in setup.cfg to something else and am not getting that error. A bunch of tests fail because it's running against MySQL or SQLite, but nothing goes wrong with the JSON tests.

setup.py seems to indicate I need pyhdb, but the test suite wants to import hdbcli and according to https://blogs.sap.com/2017/07/26/sap-hana-2.0-sps02-new-client-interface-features/ I have to go through an enormous proprietary registration / download / install process which appears to be windows-specific in any case to get to this hdbcli.

is it possible you can try testing against some other database that I have access towards and then get this error to reproduce? e.g. like mysql+pymysql, or even just sqlite://.

is it possible this is a windows-related issue?

[sqlalchemy-bot]

Patrick Buxton wrote:

I changed to point at my Postgresql/Greenplum server and it skips the tests just fine - change back to point at HANA and I get the error. That's all happening on Linux.

It's very strange because I can get it to happen in debug locally and I can watch the error occur but it makes no sense really. I can explain what appears to happen even though I don't know why yet:

In plugin_base._do_skips it calls _possible_configs_for_cls which looks at the config, sees the one entry, determines is skipped and removes it from the set and returns
When plugin_base._do_skips then immediately tries to build the 'unsupported on any DB implementation' message, the call to config.Config.all_configs() returns None because the entry in the config is no longer there.

I'm sorry, I thought you'd be able to see the error straight away - I'll have to debug further and see if I can determine what's going wrong myself.

[sqlalchemy-bot]

Patrick Buxton wrote:

OK, I got it, it's because the dialect doesn't provide a server_version_info and line 564 in plugin_base.py expects it. Is the server_version_info a definite requirement?

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

ah, well yes it's sort of a thing you should have, if you don't have one then return like, (0, 0, 0) but also I can certainly try to smooth that out on this end. wow it's just the stringification too, OK

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

easy to reproduce, thanks!

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

here we are:

https://gerrit.sqlalchemy.org/#/q/I9124d3ac5484941081127274e6eb71f392fb94f7

just return an empty tuple for now instead of None

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• set milestone to "1.2.x"

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Default server_version_info to (0, )

Fixed a bug in the test suite where if an external dialect returned
None for server_version_info, the exclusion logic would raise an
AttributeError.

Change-Id: I9124d3ac5484941081127274e6eb71f392fb94f7
Fixes: #4249
(cherry picked from commit 29ce872)

→ 97e828f

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Default server_version_info to (0, )

Fixed a bug in the test suite where if an external dialect returned
None for server_version_info, the exclusion logic would raise an
AttributeError.

Change-Id: I9124d3ac5484941081127274e6eb71f392fb94f7
Fixes: #4249

→ 29ce872