Use separate settings for django/tests and django_mongodb_backend/tests

.evergreen/run-tests.sh

@@ -15,8 +15,8 @@ pip install -e ..
 pip install -r requirements/py3.txt
 popd
 
-# Copy the test settings file
-cp ./.github/workflows/mongodb_settings.py django_repo/tests/
+# Copy the test settings files
+cp ./.github/workflows/*_settings.py django_repo/tests/
 
 # Copy the test runner file
 cp ./.github/workflows/runtests.py django_repo/tests/runtests_.py

.github/workflows/django_settings.py

@@ -0,0 +1,37 @@
+# Settings for django/tests.
+import os
+
+from pymongo.uri_parser import parse_uri
+
+if mongodb_uri := os.getenv("MONGODB_URI"):
+    db_settings = {
+        "ENGINE": "django_mongodb_backend",
+        "HOST": mongodb_uri,
+    }
+    # Workaround for https://github.com/mongodb-labs/mongo-orchestration/issues/268
+    uri = parse_uri(mongodb_uri)
+    if uri.get("username") and uri.get("password"):
+        db_settings["OPTIONS"] = {"tls": True, "tlsAllowInvalidCertificates": True}
+    DATABASES = {
+        "default": {**db_settings, "NAME": "djangotests"},
+        "other": {**db_settings, "NAME": "djangotests-other"},
+    }
+else:
+    DATABASES = {
+        "default": {
+            "ENGINE": "django_mongodb_backend",
+            "NAME": "djangotests",
+            # Required when connecting to the Atlas image in Docker.
+            "OPTIONS": {"directConnection": True},
+        },
+        "other": {
+            "ENGINE": "django_mongodb_backend",
+            "NAME": "djangotests-other",
+            "OPTIONS": {"directConnection": True},
+        },
+    }
+
+DEFAULT_AUTO_FIELD = "django_mongodb_backend.fields.ObjectIdAutoField"
+PASSWORD_HASHERS = ("django.contrib.auth.hashers.MD5PasswordHasher",)
+SECRET_KEY = "django_tests_secret_key"  # noqa: S105
+USE_TZ = False

.github/workflows/mongodb_settings.py

@@ -1,36 +1,4 @@
-import os
+# Settings for django_mongodb_backend/tests.
+from django_settings import *  # noqa: F403
 
-from pymongo.uri_parser import parse_uri
-
-if mongodb_uri := os.getenv("MONGODB_URI"):
-    db_settings = {
-        "ENGINE": "django_mongodb_backend",
-        "HOST": mongodb_uri,
-    }
-    # Workaround for https://github.com/mongodb-labs/mongo-orchestration/issues/268
-    uri = parse_uri(mongodb_uri)
-    if uri.get("username") and uri.get("password"):
-        db_settings["OPTIONS"] = {"tls": True, "tlsAllowInvalidCertificates": True}
-    DATABASES = {
-        "default": {**db_settings, "NAME": "djangotests"},
-        "other": {**db_settings, "NAME": "djangotests-other"},
-    }
-else:
-    DATABASES = {
-        "default": {
-            "ENGINE": "django_mongodb_backend",
-            "NAME": "djangotests",
-            # Required when connecting to the Atlas image in Docker.
-            "OPTIONS": {"directConnection": True},
-        },
-        "other": {
-            "ENGINE": "django_mongodb_backend",
-            "NAME": "djangotests-other",
-            "OPTIONS": {"directConnection": True},
-        },
-    }
-
-DEFAULT_AUTO_FIELD = "django_mongodb_backend.fields.ObjectIdAutoField"
-PASSWORD_HASHERS = ("django.contrib.auth.hashers.MD5PasswordHasher",)
-SECRET_KEY = "django_tests_secret_key"
-USE_TZ = False
+DATABASE_ROUTERS = ["django_mongodb_backend.routers.MongoRouter"]

.github/workflows/runtests.py

@@ -171,11 +171,19 @@
     test_apps.extend(["gis_tests", "gis_tests_"])
 
 runtests = pathlib.Path(__file__).parent.resolve() / "runtests.py"
-run_tests_cmd = f"python3 {runtests} %s --settings mongodb_settings -v 2"
+run_tests_cmd = f"python3 {runtests} %s --settings %s -v 2"
 
 shouldFail = False
 for app_name in test_apps:
-    res = os.system(run_tests_cmd % app_name)  # noqa: S605
+    # Use the custom settings module only for django_mongodb_backend's tests
+    # (which always end with an underscore). Some of Django's tests aren't
+    # compatible with extra DATABASE_ROUTERS or other DATABASES aliases.
+    settings_module = (
+        os.environ.get("DJANGO_SETTINGS_MODULE", "mongodb_settings")
+        if app_name.endswith("_")
+        else "django_settings"
+    )
+    res = os.system(run_tests_cmd % (app_name, settings_module))  # noqa: S605
     if res != 0:
         shouldFail = True
 sys.exit(1 if shouldFail else 0)

.github/workflows/test-python-atlas.yml

@@ -45,8 +45,8 @@ jobs:
           cd django_repo/tests/
           pip3 install -e ..
           pip3 install -r requirements/py3.txt
-      - name: Copy the test settings file
-        run: cp .github/workflows/mongodb_settings.py django_repo/tests/
+      - name: Copy the test settings files
+        run: cp .github/workflows/*_settings.py django_repo/tests/
       - name: Copy the test runner file
         run: cp .github/workflows/runtests.py django_repo/tests/runtests_.py
       - name: Start local Atlas

.github/workflows/test-python-geo.yml

@@ -46,8 +46,8 @@ jobs:
           cd django_repo/tests/
           pip3 install -e ..
           pip3 install -r requirements/py3.txt
-      - name: Copy the test settings file
-        run: cp .github/workflows/mongodb_settings.py django_repo/tests/
+      - name: Copy the test settings files
+        run: cp .github/workflows/*_settings.py django_repo/tests/
       - name: Copy the test runner file
         run: cp .github/workflows/runtests.py django_repo/tests/runtests_.py
       - name: Start MongoDB

.github/workflows/test-python.yml

@@ -45,8 +45,8 @@ jobs:
           cd django_repo/tests/
           pip3 install -e ..
           pip3 install -r requirements/py3.txt
-      - name: Copy the test settings file
-        run: cp .github/workflows/mongodb_settings.py django_repo/tests/
+      - name: Copy the test settings files
+        run: cp .github/workflows/*_settings.py django_repo/tests/
       - name: Copy the test runner file
         run: cp .github/workflows/runtests.py django_repo/tests/runtests_.py
       - name: Start MongoDB

docs/internals/contributing/unit-tests.rst

@@ -66,6 +66,7 @@ Then, create a test settings file, ``django-repo/tests/test_mongo.py``::
         },
     }
 
+    DATABASE_ROUTERS = ["django_mongodb_backend.routers.MongoRouter"]
     DEFAULT_AUTO_FIELD = "django_mongodb_backend.fields.ObjectIdAutoField"
 
 Finally, you can run the test script in the Django repository:

pyproject.toml

@@ -103,11 +103,6 @@ unfixable = []
 exclude = []
 dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?)|dummy.*)$"
 
-[tool.ruff.lint.per-file-ignores]
-".github/workflows/mongodb_settings.py" = [
-    "S105",  # Possible hardcoded password assigned to: "SECRET_KEY"
-]
-
 [tool.coverage.report]
 exclude_lines = [
     "if (.*and +)*_use_c( and.*)*:",