after all that, use pytest warnings plugin

The warnings plugin lets us set the filters up
in the config, and as our filter requirements are now
simple we can just set this up.

additionally pytest now recommends pyproject.toml, since
we fully include this now, let's move it there.

the pytest logging plugin seems to not be any problem either
at the moment, so re-enable that.  if it becomes apparent
whatever the problem was (which was probably that it was just
surprising, or something) we can disable it again and comment
what the reason was.

Change-Id: Ia9715533b01f72aa5fdcf6a27ce75b76f829fa43

lib/sqlalchemy/exc.py

@@ -672,6 +672,15 @@ class NotSupportedError(DatabaseError):
 # Warnings
 
 
+class SATestSuiteWarning(Warning):
+    """warning for a condition detected during tests that is non-fatal
+
+    Currently outside of SAWarning so that we can work around tools like
+    Alembic doing the wrong thing with warnings.
+
+    """
+
+
 class SADeprecationWarning(HasDescriptionCode, DeprecationWarning):
     """Issued for usage of deprecated APIs."""
 

lib/sqlalchemy/pool/base.py

@@ -757,13 +757,14 @@ def _finalize_fairy(
                 else:
                     message = (
                         "The garbage collector is trying to clean up "
-                        "connection %r. This feature is unsupported on async "
+                        f"connection {dbapi_connection!r}. This feature is "
+                        "unsupported on async "
                         "dbapi, since no IO can be performed at this stage to "
                         "reset the connection. Please close out all "
                         "connections when they are no longer used, calling "
                         "``close()`` or using a context manager to "
                         "manage their lifetime."
-                    ) % dbapi_connection
+                    )
                     pool.logger.error(message)
                     util.warn(message)
 
@@ -779,6 +780,14 @@ def _finalize_fairy(
     if connection_record and connection_record.fairy_ref is not None:
         connection_record.checkin()
 
+    # give gc some help.  See
+    # test/engine/test_pool.py::PoolEventsTest::test_checkin_event_gc[True]
+    # which actually started failing when pytest warnings plugin was
+    # turned on, due to util.warn() above
+    del dbapi_connection
+    del connection_record
+    del fairy
+
 
 # a dictionary of the _ConnectionFairy weakrefs to _ConnectionRecord, so that
 # GC under pypy will call ConnectionFairy finalizers.  linked directly to the

lib/sqlalchemy/testing/warnings.py

@@ -4,54 +4,26 @@
 #
 # This module is part of SQLAlchemy and is released under
 # the MIT License: https://www.opensource.org/licenses/mit-license.php
-import warnings
-
 from . import assertions
 from .. import exc as sa_exc
+from ..exc import SATestSuiteWarning
 from ..util.langhelpers import _warnings_warn
 
 
-class SATestSuiteWarning(Warning):
-    """warning for a condition detected during tests that is non-fatal
-
-    Currently outside of SAWarning so that we can work around tools like
-    Alembic doing the wrong thing with warnings.
-
-    """
-
-
 def warn_test_suite(message):
     _warnings_warn(message, category=SATestSuiteWarning)
 
 
 def setup_filters():
-    """Set global warning behavior for the test suite."""
+    """hook for setting up warnings filters.
 
-    # TODO: at this point we can use the normal pytest warnings plugin,
-    # if we decide the test suite can be linked to pytest only
+    Note that when the pytest warnings plugin is in place, that plugin
+    overwrites whatever happens here.
 
-    origin = r"^(?:test|sqlalchemy)\..*"
+    Current SQLAlchemy 2.0 default is to use pytest warnings plugin
+    which is configured in pyproject.toml.
 
-    warnings.filterwarnings(
-        "ignore", category=sa_exc.SAPendingDeprecationWarning
-    )
-    warnings.filterwarnings("error", category=sa_exc.SADeprecationWarning)
-    warnings.filterwarnings("error", category=sa_exc.SAWarning)
-
-    warnings.filterwarnings("always", category=SATestSuiteWarning)
-
-    warnings.filterwarnings(
-        "error", category=DeprecationWarning, module=origin
-    )
-
-    try:
-        import pytest
-    except ImportError:
-        pass
-    else:
-        warnings.filterwarnings(
-            "once", category=pytest.PytestDeprecationWarning, module=origin
-        )
+    """
 
 
 def assert_warnings(fn, warning_msgs, regex=False):

pyproject.toml

@@ -9,3 +9,17 @@
 [tool.black]
 line-length = 79
 target-version = ['py37']
+
+
+[tool.pytest.ini_options]
+addopts = "--tb native -v -r sfxX --maxfail=250 -p warnings -p logging"
+python_files = "test/*test_*.py"
+minversion = "6.2"
+filterwarnings = [
+    "ignore::sqlalchemy.exc.SAPendingDeprecationWarning",
+    "error::sqlalchemy.exc.SADeprecationWarning",
+    "error::sqlalchemy.exc.SAWarning",
+    "always::sqlalchemy.exc.SATestSuiteWarning",
+    "error::DeprecationWarning:test",
+    "error::DeprecationWarning:sqlalchemy"
+]

setup.cfg

@@ -85,9 +85,8 @@ tag_build = dev
 [options.packages.find]
 where = lib
 
-[tool:pytest]
-addopts = --tb native -v -r sfxX --maxfail=250 -p no:warnings -p no:logging
-python_files = test/*test_*.py
+# [tool:pytest]
+# pytest settings moved to pyproject.toml
 
 [upload]
 sign = 1

test/base/test_except.py

@@ -511,6 +511,7 @@ ALL_EXC = [
         [lambda cls: cls("foo", code="42")],
     ),
     ([sa_exceptions.SAPendingDeprecationWarning], [lambda cls: cls(1, 2, 3)]),
+    ([sa_exceptions.SATestSuiteWarning], [lambda cls: cls()]),
 ]
 
 

test/conftest.py

@@ -16,6 +16,8 @@ os.environ["SQLALCHEMY_WARN_20"] = "true"
 
 collect_ignore_glob = []
 
+# this requires that sqlalchemy.testing was not already
+# imported in order to work
 pytest.register_assert_rewrite("sqlalchemy.testing.assertions")