Restores the expected behavior of certain fixtures, while fixing a bug related to fixtures now tearing down properly

.travis.yml

@@ -1,10 +1,11 @@
 language: python
 dist: xenial
+cache: false
 
 jobs:
   fast_finish: true
   include:
-    - stage: baseline
+    - stage: test
       python: 3.6
       env:
         - TOXENV=py36-dj20-postgres-xdist-coverage
@@ -97,7 +98,7 @@ install:
   - pip install tox==3.9.0
 
 script:
-  - tox
+  - tox --force-dep "pytest@git+https://github.com/blueyed/pytest@fixture-stack#egg=pytest"
 
 after_success:
   - |

pytest_django/fixtures.py

@@ -36,28 +36,34 @@
 def django_db_modify_db_settings_tox_suffix():
     skip_if_no_django()
 
-    tox_environment = os.getenv("TOX_PARALLEL_ENV")
-    if tox_environment:
-        # Put a suffix like _py27-django21 on tox workers
-        _set_suffix_to_test_databases(suffix=tox_environment)
+    return os.getenv("TOX_PARALLEL_ENV")
 
 
 @pytest.fixture(scope="session")
 def django_db_modify_db_settings_xdist_suffix(request):
     skip_if_no_django()
 
-    xdist_suffix = getattr(request.config, "slaveinput", {}).get("slaveid")
-    if xdist_suffix:
-        # Put a suffix like _gw0, _gw1 etc on xdist processes
-        _set_suffix_to_test_databases(suffix=xdist_suffix)
+    return getattr(request.config, "slaveinput", {}).get("slaveid")
 
 
 @pytest.fixture(scope="session")
 def django_db_modify_db_settings_parallel_suffix(
     django_db_modify_db_settings_tox_suffix,
-    django_db_modify_db_settings_xdist_suffix,
+    django_db_modify_db_settings_xdist_suffix
 ):
     skip_if_no_django()
+    xdist_worker = django_db_modify_db_settings_xdist_suffix
+    tox_environment = django_db_modify_db_settings_tox_suffix
+    suffix_parts = []
+    if tox_environment:
+        # Put a suffix like _py27-django21 on tox workers
+        suffix_parts.append(tox_environment)
+    if xdist_worker:
+        # Put a suffix like _gw0, _gw1 etc on xdist processes
+        suffix_parts.append(xdist_worker)
+    suffix = "_".join(suffix_parts)
+    if suffix:
+        _set_suffix_to_test_databases(suffix=suffix)
 
 
 @pytest.fixture(scope="session")
@@ -84,7 +90,7 @@ def django_db_createdb(request):
 def django_db_setup(
     request,
     django_test_environment,
-    django_db_blocker,
+    _django_db_blocker,
     django_db_use_migrations,
     django_db_keepdb,
     django_db_createdb,
@@ -101,15 +107,16 @@ def django_db_setup(
     if django_db_keepdb and not django_db_createdb:
         setup_databases_args["keepdb"] = True
 
-    with django_db_blocker.unblock():
+    with _django_db_blocker.unblock():
         db_cfg = setup_databases(
             verbosity=request.config.option.verbose,
             interactive=False,
             **setup_databases_args
         )
 
-    def teardown_database():
-        with django_db_blocker.unblock():
+    yield
+    if not django_db_keepdb:
+        with _django_db_blocker.unblock():
             try:
                 teardown_databases(db_cfg, verbosity=request.config.option.verbose)
             except Exception as exc:
@@ -119,9 +126,6 @@ def teardown_database():
                     )
                 )
 
-    if not django_db_keepdb:
-        request.addfinalizer(teardown_database)
-
 
 def _django_db_fixture_helper(
     request, django_db_blocker, transactional=False, reset_sequences=False
@@ -191,7 +195,7 @@ def _set_suffix_to_test_databases(suffix):
 
 
 @pytest.fixture(scope="function")
-def db(request, django_db_setup, django_db_blocker):
+def db(request, django_db_blocker):
     """Require a django test database.
 
     This database will be setup with the default fixtures and will have
@@ -429,13 +433,15 @@ def _live_server_helper(request):
     It will also override settings only for the duration of the test.
     """
     if "live_server" not in request.fixturenames:
+        yield
         return
 
     request.getfixturevalue("transactional_db")
 
     live_server = request.getfixturevalue("live_server")
     live_server._live_server_modified_settings.enable()
-    request.addfinalizer(live_server._live_server_modified_settings.disable)
+    yield
+    live_server._live_server_modified_settings.disable()
 
 
 @contextmanager

pytest_django/plugin.py

@@ -462,7 +462,7 @@ def django_test_environment(request):
 
 
 @pytest.fixture(scope="session")
-def django_db_blocker():
+def _django_db_blocker():
     """Wrapper around Django's database access.
 
     This object can be used to re-enable database access.  This fixture is used
@@ -481,6 +481,28 @@ def django_db_blocker():
     return _blocking_manager
 
 
+@pytest.fixture(scope="session")
+def django_db_blocker(django_db_setup, _django_db_blocker):  # noqa: F811
+    """Wrapper around _django_db_blocker to serve as convenience reference.
+
+    The ``_django_db_blocker`` fixture must be available for the ``django_db_setup``
+    fixture, so ``django_db_setup`` must request the ``_django_db_blocker`` fixture. But
+    in order for ``_django_db_blocker`` to be used, ``django_db_setup`` must also have
+    been executed, suggesting that ``_django_db_blocker`` should request
+    ``django_db_setup``, especially since it is possible for ``_django_db_blocker`` to
+    be needed when ``django_db_setup`` wouldn't normally have been run (e.g. if a test
+    isn't marked with ``pytest.mark.django_db``).
+
+    This would normally cause a catch-22, but to circumvent this, the
+    `_django_db_blocker`` fixture is used behind the scenes, while ``django_db_blocker``
+    serves as the fixture used by everything that would normally need the blocker (aside
+    from ``django_db_setup``). This fixture helps coordinate between both
+    ``django_db_setup`` and ``_django_db_blocker``, so that whenever
+    ``django_db_blocker`` gets used, it ensures ``django_db_setup`` is run first.
+    """
+    return _django_db_blocker
+
+
 @pytest.fixture(autouse=True)
 def _django_db_marker(request):
     """Implement the django_db marker, internal to pytest-django.
@@ -500,7 +522,7 @@ def _django_db_marker(request):
 
 
 @pytest.fixture(autouse=True, scope="class")
-def _django_setup_unittest(request, django_db_blocker):
+def _django_setup_unittest(request, _django_db_blocker):
     """Setup a django unittest, internal to pytest-django."""
     if not django_settings_is_configured() or not is_django_unittest(request):
         yield
@@ -525,7 +547,7 @@ def non_debugging_runtest(self):
 
     cls = request.node.cls
 
-    with django_db_blocker.unblock():
+    with _django_db_blocker.unblock():
         if _handle_unittest_methods:
             _restore_class_methods(cls)
             cls.setUpClass()
@@ -736,7 +758,7 @@ def __exit__(self, exc_type, exc_value, traceback):
 class _DatabaseBlocker(object):
     """Manager for django.db.backends.base.base.BaseDatabaseWrapper.
 
-    This is the object returned by django_db_blocker.
+    This is the object returned by _django_db_blocker and django_db_blocker.
     """
 
     def __init__(self):

pytest_django_test/settings_base.py

@@ -1,5 +1,3 @@
-import os
-
 import django
 
 ROOT_URLCONF = "pytest_django_test.urls"
@@ -14,10 +12,6 @@
 STATIC_URL = "/static/"
 SECRET_KEY = "foobar"
 
-# Used to construct unique test database names to allow detox to run multiple
-# versions at the same time
-db_suffix = "_%s" % os.getuid()
-
 MIDDLEWARE = [
     "django.contrib.sessions.middleware.SessionMiddleware",
     "django.middleware.common.CommonMiddleware",

pytest_django_test/settings_mysql_innodb.py

@@ -1,9 +1,9 @@
-from .settings_base import *  # noqa: F403
+from .settings_base import *  # noqa: F401 F403
 
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.mysql",
-        "NAME": "pytest_django" + db_suffix,  # noqa: F405
+        "NAME": "pytest_django_should_never_get_accessed",
         "HOST": "localhost",
         "USER": "root",
         "OPTIONS": {"init_command": "SET default_storage_engine=InnoDB"},

pytest_django_test/settings_mysql_myisam.py

@@ -1,9 +1,9 @@
-from pytest_django_test.settings_base import *  # noqa: F403
+from .settings_base import *  # noqa: F401 F403
 
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.mysql",
-        "NAME": "pytest_django" + db_suffix,  # noqa: F405
+        "NAME": "pytest_django_should_never_get_accessed",
         "HOST": "localhost",
         "USER": "root",
         "OPTIONS": {"init_command": "SET default_storage_engine=MyISAM"},

pytest_django_test/settings_postgres.py

@@ -1,4 +1,4 @@
-from pytest_django_test.settings_base import *  # noqa
+from .settings_base import *  # noqa: F401 F403
 
 # PyPy compatibility
 try:
@@ -12,7 +12,7 @@
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.postgresql_psycopg2",
-        "NAME": "pytest_django" + db_suffix,  # noqa
+        "NAME": "pytest_django_should_never_get_accessed",
         "HOST": "localhost",
         "USER": "",
     }

pytest_django_test/settings_sqlite.py

@@ -1,4 +1,4 @@
-from .settings_base import *  # noqa
+from .settings_base import *  # noqa: F401 F403
 
 DATABASES = {
     "default": {

pytest_django_test/settings_sqlite_file.py

@@ -1,6 +1,6 @@
 import tempfile
 
-from pytest_django_test.settings_base import *  # noqa
+from .settings_base import *  # noqa: F401 F403
 
 # This is a SQLite configuration, which uses a file based database for
 # tests (via setting TEST_NAME / TEST['NAME']).
@@ -11,7 +11,7 @@
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.sqlite3",
-        "NAME": "/should_never_be_accessed",
+        "NAME": "/pytest_django_should_never_get_accessed",
         "TEST": {"NAME": _filename},
     }
 }

tests/test_db_access_in_repr.py

@@ -5,7 +5,7 @@ def test_db_access_with_repr_in_report(django_testdir):
 
         from .app.models import Item
 
-        def test_via_db_blocker(django_db_setup, django_db_blocker):
+        def test_via_db_blocker(django_db_blocker):
             with django_db_blocker.unblock():
                 Item.objects.get(name='This one is not there')
 

tests/test_db_setup.py

@@ -159,32 +159,34 @@ def test_xdist_with_reuse(django_testdir):
 
         from .app.models import Item
 
-        def _check(settings):
+        def _check(settings, worker_id):
             # Make sure that the database name looks correct
             db_name = settings.DATABASES['default']['NAME']
-            assert db_name.endswith('_gw0') or db_name.endswith('_gw1')
-
+            assert db_name == (
+                'test_pytest_django_should_never_get_accessed_inner_inner_{}'
+                .format(worker_id)
+            )
             assert Item.objects.count() == 0
             Item.objects.create(name='foo')
             assert Item.objects.count() == 1
 
 
         @pytest.mark.django_db
-        def test_a(settings):
-            _check(settings)
+        def test_a(settings, worker_id):
+            _check(settings, worker_id)
 
 
         @pytest.mark.django_db
-        def test_b(settings):
-            _check(settings)
+        def test_b(settings, worker_id):
+            _check(settings, worker_id)
 
         @pytest.mark.django_db
-        def test_c(settings):
-            _check(settings)
+        def test_c(settings, worker_id):
+            _check(settings, worker_id)
 
         @pytest.mark.django_db
-        def test_d(settings):
-            _check(settings)
+        def test_d(settings, worker_id):
+            _check(settings, worker_id)
     """
     )
 
@@ -270,7 +272,7 @@ def test_sqlite_database_renamed(self, django_testdir):
             from django.db import connections
 
             @pytest.mark.django_db
-            def test_a():
+            def test_a(worker_id):
                 (conn_db2, conn_default) = sorted(
                     connections.all(),
                     key=lambda conn: conn.alias,
@@ -288,7 +290,7 @@ def test_a():
 
                 assert conn_db2.vendor == 'sqlite'
                 db_name = conn_db2.creation._get_test_db_name()
-                assert db_name.startswith('test_custom_db_name_gw')
+                assert db_name == 'test_custom_db_name_{}'.format(worker_id)
         """
         )
 
@@ -377,13 +379,15 @@ def test_db_with_tox_suffix(self, django_testdir, monkeypatch):
             from django.db import connections
 
             @pytest.mark.django_db
-            def test_inner():
+            def test_inner(worker_id):
 
                 (conn, ) = connections.all()
 
                 assert conn.vendor == 'sqlite'
                 db_name = conn.creation._get_test_db_name()
-                assert db_name.startswith('test_custom_db_name_py37-django22_gw')
+                assert db_name == 'test_custom_db_name_py37-django22_{}'.format(
+                    worker_id,
+                )
         """
         )
 

tox.ini

@@ -27,6 +27,8 @@ deps =
     postgres: psycopg2-binary
     coverage: coverage-enable-subprocess
 
+    pytest
+
     pytest41: pytest>=4.1,<4.2
     pytest41: attrs==17.4.0
     xdist: pytest-xdist>=1.15