- Support has been added for pytest to run tests. This runner

is currently being supported in addition to nose, and will likely
be preferred to nose going forward.   The nose plugin system used
by SQLAlchemy has been split out so that it works under pytest as
well.  There are no plans to drop support for nose at the moment
and we hope that the test suite itself can continue to remain as
agnostic of testing platform as possible.  See the file
README.unittests.rst for updated information on running tests
with pytest.

The test plugin system has also been enhanced to support running
tests against mutiple database URLs at once, by specifying the ``--db``
and/or ``--dburi`` flags multiple times.  This does not run the entire test
suite for each database, but instead allows test cases that are specific
to certain backends make use of that backend as the test is run.
When using pytest as the test runner, the system will also run
specific test suites multiple times, once for each database, particularly
those tests within the "dialect suite".   The plan is that the enhanced
system will also be used by Alembic, and allow Alembic to run
migration operation tests against multiple backends in one run, including
third-party backends not included within Alembic itself.
Third party dialects and extensions are also encouraged to standardize
on SQLAlchemy's test suite as a basis; see the file README.dialects.rst
for background on building out from SQLAlchemy's test platform.

1 files changed, 125 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/plugin/pytestplugin.py b/lib/sqlalchemy/testing/plugin/pytestplugin.py
new file mode 100644
index 000000000..352cbbd5f
--- /dev/null
+++ b/lib/sqlalchemy/testing/plugin/pytestplugin.py
@@ -0,0 +1,125 @@
+import pytest
+import argparse
+import inspect
+from . import plugin_base
+import collections
+
+def pytest_addoption(parser):
+    group = parser.getgroup("sqlalchemy")
+
+    def make_option(name, **kw):
+        callback_ = kw.pop("callback", None)
+        if callback_:
+            class CallableAction(argparse.Action):
+                def __call__(self, parser, namespace, values, option_string=None):
+                    callback_(option_string, values, parser)
+            kw["action"] = CallableAction
+
+        group.addoption(name, **kw)
+
+    plugin_base.setup_options(make_option)
+    plugin_base.read_config()
+
+def pytest_configure(config):
+    plugin_base.pre_begin(config.option)
+
+    plugin_base.set_coverage_flag(bool(getattr(config.option, "cov_source", False)))
+
+    plugin_base.post_begin()
+
+
+def pytest_collection_modifyitems(session, config, items):
+    # look for all those classes that specify __multiple__ and
+    # expand them out into per-database test cases.
+
+    # this is much easier to do within pytest_pycollect_makeitem, however
+    # pytest is iterating through cls.__dict__ as makeitem is
+    # called which causes a "dictionary changed size" error on py3k.
+    # I'd submit a pullreq for them to turn it into a list first, but
+    # it's to suit the rather odd use case here which is that we are adding
+    # new classes to a module on the fly.
+
+    rebuilt_items = collections.defaultdict(list)
+    test_classes = set(item.parent for item in items)
+    for test_class in test_classes:
+        for sub_cls in plugin_base.generate_sub_tests(test_class.cls, test_class.parent.module):
+            if sub_cls is not test_class.cls:
+                list_ = rebuilt_items[test_class.cls]
+
+                for inst in pytest.Class(sub_cls.__name__,
+                                parent=test_class.parent.parent).collect():
+                    list_.extend(inst.collect())
+
+    newitems = []
+    for item in items:
+        if item.parent.cls in rebuilt_items:
+            newitems.extend(rebuilt_items[item.parent.cls])
+            rebuilt_items[item.parent.cls][:] = []
+        else:
+            newitems.append(item)
+
+    # seems like the functions attached to a test class aren't sorted already?
+    # is that true and why's that? (when using unittest, they're sorted)
+    items[:] = sorted(newitems, key=lambda item: (
+                                        item.parent.parent.parent.name,
+                                        item.parent.parent.name,
+                                        item.name
+                                    )
+                        )
+
+
+
+def pytest_pycollect_makeitem(collector, name, obj):
+
+    if inspect.isclass(obj) and plugin_base.want_class(obj):
+        return pytest.Class(name, parent=collector)
+    elif inspect.isfunction(obj) and \
+            name.startswith("test_") and \
+            isinstance(collector, pytest.Instance):
+        return pytest.Function(name, parent=collector)
+    else:
+        return []
+
+_current_class = None
+
+def pytest_runtest_setup(item):
+    # here we seem to get called only based on what we collected
+    # in pytest_collection_modifyitems.   So to do class-based stuff
+    # we have to tear that out.
+    global _current_class
+
+    if not isinstance(item, pytest.Function):
+        return
+
+    # ... so we're doing a little dance here to figure it out...
+    if item.parent.parent is not _current_class:
+
+        class_setup(item.parent.parent)
+        _current_class = item.parent.parent
+
+        # this is needed for the class-level, to ensure that the
+        # teardown runs after the class is completed with its own
+        # class-level teardown...
+        item.parent.parent.addfinalizer(lambda: class_teardown(item.parent.parent))
+
+    test_setup(item)
+
+def pytest_runtest_teardown(item):
+    # ...but this works better as the hook here rather than
+    # using a finalizer, as the finalizer seems to get in the way
+    # of the test reporting failures correctly (you get a bunch of
+    # py.test assertion stuff instead)
+    test_teardown(item)
+
+def test_setup(item):
+    id_ = "%s.%s:%s" % (item.parent.module.__name__, item.parent.name, item.name)
+    plugin_base.before_test(item, id_)
+
+def test_teardown(item):
+    plugin_base.after_test(item)
+
+def class_setup(item):
+    plugin_base.start_test_class(item.cls)
+
+def class_teardown(item):
+    plugin_base.stop_test_class(item.cls)