gistfile1.txt

# run #1 - run with just --db sqlite, one test is generated/runs

classics-MacBook-Pro-2:sqlalchemy classic$ py.test test/dialect/test_suite.py --db sqlite -k HasTableTest                
============================================================= test session starts ==============================================================
platform darwin -- Python 2.7.5 -- py-1.4.20 -- pytest-2.5.2 -- /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
plugins: cov
collected 121 items 

test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_reflection.py:31: HasTableTest_sqlite_pysqlite.test_has_table PASSED

=================================================== 120 tests deselected by '-kHasTableTest' ===================================================
=================================================== 1 passed, 120 deselected in 0.06 seconds ===================================================



# run #2 - run with --db sqlite --db postgresql --db mysql, three copies are generated, one for each DB

classics-MacBook-Pro-2:sqlalchemy classic$ py.test test/dialect/test_suite.py --db sqlite --db postgresql --db mysql -k HasTableTest 
============================================================= test session starts ==============================================================
platform darwin -- Python 2.7.5 -- py-1.4.20 -- pytest-2.5.2 -- /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
plugins: cov
collected 183 items 

test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_reflection.py:31: HasTableTest_mysql_mysqldb.test_has_table PASSED
test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_reflection.py:31: HasTableTest_sqlite_pysqlite.test_has_table PASSED
test/dialect/test_suite.py <- lib/sqlalchemy/testing/suite/test_reflection.py:31: HasTableTest_postgresql_psycopg2.test_has_table PASSED

=================================================== 180 tests deselected by '-kHasTableTest' ===================================================
=================================================== 3 passed, 180 deselected in 0.16 seconds ===================================================
classics-MacBook-Pro-2:sqlalchemy classic$ 


this is the hook, I'm not sure if I'm allowed to poke into the "unittest" plugin like this but this is how it had to be:

def pytest_configure(config):
    # because it feels icky importing from "_pytest"..
    global py_unittest
    py_unittest = config.pluginmanager.getplugin('unittest')


def pytest_pycollect_makeitem(collector, name, obj):
    if inspect.isclass(obj) and plugin_base.want_class(obj):
        sub_objs = list(plugin_base.generate_sub_tests(obj))
        for sub_obj in sub_objs:
            if name != sub_obj.__name__:
                setattr(collector.module, sub_obj.__name__, sub_obj)
        return [
            py_unittest.UnitTestCase(sub_obj.__name__, parent=collector)
            for sub_obj in sub_objs
        ]

# elsewhere....just generate classes for certain test classes

def generate_sub_tests(cls):
    if getattr(cls, '__multiple__', False):
        for cfg in config.Config.all_configs():
            name = "%s_%s_%s" % (cls.__name__, cfg.db.name, cfg.db.driver)
            yield type(
                        name,
                        (cls, ),
                        {
                            "__only_on__": (cfg.db.name, cfg.db.driver),
                            "__multiple__": False}
                        )
    else:
        yield cls