[WIP] Make django_settings_is_configured return the first value always

pytest_django/lazy_django.py

@@ -24,7 +24,7 @@ def django_settings_is_configured():
     ret = bool(os.environ.get("DJANGO_SETTINGS_MODULE"))
 
     if not ret and "django.conf" in sys.modules:
-        return sys.modules["django.conf"].settings.configured
+        ret = sys.modules["django.conf"].settings.configured
 
     return ret
 

pytest_django/plugin.py

@@ -451,8 +451,13 @@ def get_order_number(test):
     items[:] = sorted(items, key=get_order_number)
 
 
+@pytest.fixture(scope="session")
+def _django_settings_is_configured():
+    return django_settings_is_configured()
+
+
 @pytest.fixture(autouse=True, scope="session")
-def django_test_environment(request):
+def django_test_environment(_django_settings_is_configured):
     """
     Ensure that Django is loaded and has its testing environment setup.
 
@@ -463,18 +468,22 @@ def django_test_environment(request):
         without duplicating a lot more of Django's test support code
         we need to follow this model.
     """
-    if django_settings_is_configured():
+    if _django_settings_is_configured:
         _setup_django()
         from django.conf import settings as dj_settings
         from django.test.utils import setup_test_environment, teardown_test_environment
 
         dj_settings.DEBUG = False
         setup_test_environment()
-        request.addfinalizer(teardown_test_environment)
+
+    yield
+
+    if _django_settings_is_configured:
+        teardown_test_environment()
 
 
 @pytest.fixture(scope="session")
-def django_db_blocker():
+def django_db_blocker(_django_settings_is_configured):
     """Wrapper around Django's database access.
 
     This object can be used to re-enable database access.  This fixture is used
@@ -487,10 +496,8 @@ def django_db_blocker():
     This is an advanced feature that is meant to be used to implement database
     fixtures.
     """
-    if not django_settings_is_configured():
-        return None
-
-    return _blocking_manager
+    if _django_settings_is_configured:
+        return _blocking_manager
 
 
 @pytest.fixture(autouse=True)
@@ -512,9 +519,9 @@ 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, _django_settings_is_configured):
     """Setup a django unittest, internal to pytest-django."""
-    if not django_settings_is_configured() or not is_django_unittest(request):
+    if not _django_settings_is_configured or not is_django_unittest(request):
         yield
         return
 
@@ -553,34 +560,33 @@ def _cleaning_debug(self):
 
 
 @pytest.fixture(scope="function", autouse=True)
-def _dj_autoclear_mailbox():
-    if not django_settings_is_configured():
-        return
-
-    from django.core import mail
+def _dj_autoclear_mailbox(_django_settings_is_configured):
+    if _django_settings_is_configured:
+        from django.core import mail
 
-    del mail.outbox[:]
+        del mail.outbox[:]
 
 
 @pytest.fixture(scope="function")
-def mailoutbox(monkeypatch, django_mail_patch_dns, _dj_autoclear_mailbox):
-    if not django_settings_is_configured():
-        return
-
-    from django.core import mail
+def mailoutbox(django_mail_patch_dns, _dj_autoclear_mailbox,
+               _django_settings_is_configured):
+    if _django_settings_is_configured:
+        from django.core import mail
 
-    return mail.outbox
+        return mail.outbox
 
 
 @pytest.fixture(scope="function")
-def django_mail_patch_dns(monkeypatch, django_mail_dnsname):
-    from django.core import mail
+def django_mail_patch_dns(monkeypatch, django_mail_dnsname,
+                          _django_settings_is_configured):
+    if _django_settings_is_configured:
+        from django.core import mail
 
-    monkeypatch.setattr(mail.message, "DNS_NAME", django_mail_dnsname)
+        monkeypatch.setattr(mail.message, "DNS_NAME", django_mail_dnsname)
 
 
 @pytest.fixture(scope="function")
-def django_mail_dnsname(monkeypatch):
+def django_mail_dnsname():
     return "fake-tests.example.com"
 
 
@@ -615,7 +621,7 @@ def restore():
 
 
 @pytest.fixture(autouse=True, scope="session")
-def _fail_for_invalid_template_variable(request):
+def _fail_for_invalid_template_variable(_django_settings_is_configured):
     """Fixture that fails for invalid variables in templates.
 
     This fixture will fail each test that uses django template rendering
@@ -687,7 +693,7 @@ def __mod__(self, var):
 
     if (
         os.environ.get(INVALID_TEMPLATE_VARS_ENV, "false") == "true"
-        and django_settings_is_configured()
+        and _django_settings_is_configured
     ):
         from django.conf import settings as dj_settings
 
@@ -700,12 +706,12 @@ def __mod__(self, var):
 
 
 @pytest.fixture(autouse=True)
-def _template_string_if_invalid_marker(request):
+def _template_string_if_invalid_marker(request, _django_settings_is_configured):
     """Apply the @pytest.mark.ignore_template_errors marker,
      internal to pytest-django."""
     marker = request.keywords.get("ignore_template_errors", None)
     if os.environ.get(INVALID_TEMPLATE_VARS_ENV, "false") == "true":
-        if marker and django_settings_is_configured():
+        if marker and _django_settings_is_configured:
             from django.conf import settings as dj_settings
 
             if dj_settings.TEMPLATES:
@@ -715,12 +721,11 @@ def _template_string_if_invalid_marker(request):
 
 
 @pytest.fixture(autouse=True, scope="function")
-def _django_clear_site_cache():
+def _django_clear_site_cache(_django_settings_is_configured):
     """Clears ``django.contrib.sites.models.SITE_CACHE`` to avoid
     unexpected behavior with cached site objects.
     """
-
-    if django_settings_is_configured():
+    if _django_settings_is_configured:
         from django.conf import settings as dj_settings
 
         if "django.contrib.sites" in dj_settings.INSTALLED_APPS:

tests/test_django_settings_module.py

@@ -450,3 +450,35 @@ def test_no_django_settings_but_django_imported(testdir, monkeypatch):
     testdir.makeconftest("import django")
     r = testdir.runpytest_subprocess("--help")
     assert r.ret == 0
+
+
+def test_django_settings_is_configured_first(testdir, monkeypatch):
+    """
+    The value from ``django_settings_is_configured`` should be used internally
+    always.
+
+    This avoids having the _dj_autoclear_mailbox autouse fixture trigger
+    "AttributeError: module 'django.core.mail' has no attribute 'outbox'",
+    because Django / the test environment was not setup initially.
+    """
+    monkeypatch.delenv("DJANGO_SETTINGS_MODULE")
+
+    p = testdir.makepyfile(
+        """
+        from pytest_django.lazy_django import django_settings_is_configured
+
+        def test_1(_django_settings_is_configured):
+            import os
+
+            assert not _django_settings_is_configured
+            assert not django_settings_is_configured()
+
+            os.environ["DJANGO_SETTINGS_MODULE"] = "ignored_dsm"
+
+        def test_2(_django_settings_is_configured):
+            assert not _django_settings_is_configured
+            assert django_settings_is_configured()
+        """)
+    result = testdir.runpytest_subprocess(p, "-s")
+    result.stdout.fnmatch_lines(["*2 passed in*"])
+    assert result.ret == 0