Allow running the mongo test suite against mongomock

Makefile

@@ -65,6 +65,7 @@ test:
 		-Wdefault:"parameter codeset is deprecated":DeprecationWarning:: \
 		-Wdefault:"'cgi' is deprecated and slated for removal in Python 3.13":DeprecationWarning:: \
 		-Wdefault:"datetime.datetime.utcfromtimestamp() is deprecated and scheduled for removal in a future version.":DeprecationWarning:: \
+		-Wdefault:"pkg_resources is deprecated as an API.":DeprecationWarning:: \
 		-m unittest
 
 # DOC: Test the examples

setup.cfg

@@ -51,6 +51,7 @@ dev =
     SQLAlchemy
     sqlalchemy_utils
     mongoengine
+    mongomock
     wheel>=0.32.0
     tox
     zest.releaser[recommended]

tests/test_mongoengine.py

@@ -6,7 +6,7 @@
 import unittest
 
 try:
-    import mongoengine
+    import mongoengine.connection
 except ImportError:
     raise unittest.SkipTest("mongodb tests disabled.")
 
@@ -38,15 +38,14 @@ class Meta:
     address = factory.SubFactory(AddressFactory)
 
 
-class MongoEngineTestCase(unittest.TestCase):
-
+class BaseMongoEngineTestCase:
     db_name = os.environ.get('MONGO_DATABASE', 'factory_boy_test')
     db_host = os.environ.get('MONGO_HOST', 'localhost')
     db_port = int(os.environ.get('MONGO_PORT', '27017'))
     server_timeout_ms = int(os.environ.get('MONGO_TIMEOUT', '300'))
 
     @classmethod
-    def setUpClass(cls):
+    def setUpClass(cls, **kwargs):
         from pymongo import read_preferences as mongo_rp
         cls.db = mongoengine.connect(
             db=cls.db_name,
@@ -57,11 +56,15 @@ def setUpClass(cls):
             # PyMongo>=2.1 has a 20s timeout, use 100ms instead
             serverselectiontimeoutms=cls.server_timeout_ms,
             uuidRepresentation='standard',
+            **kwargs,
         )
 
-    @classmethod
-    def tearDownClass(cls):
-        cls.db.drop_database(cls.db_name)
+        def cleanup():
+            cls.db.drop_database(cls.db_name)
+            mongoengine.connection.disconnect()
+            PersonFactory.reset_sequence()
+            AddressFactory.reset_sequence()
+        cls.addClassCleanup(cleanup)
 
     def test_build(self):
         std = PersonFactory.build()
@@ -74,3 +77,22 @@ def test_creation(self):
         self.assertEqual('name1', std1.name)
         self.assertEqual('street1', std1.address.street)
         self.assertIsNotNone(std1.id)
+
+
+class MongoEngineTestCase(BaseMongoEngineTestCase, unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        if os.environ.get('MONGO_USE_MOCK', '0') == '1':
+            raise unittest.SkipTest("Using mongomock, do not run the test suite against MongoDB.")
+        super().setUpClass()
+
+
+class MockMongoEngineTestCase(BaseMongoEngineTestCase, unittest.TestCase):
+    """
+    In some environments, MongoDB isn’t available.
+    Run this smoke test instead.
+    """
+    @classmethod
+    def setUpClass(cls):
+        import mongomock
+        super().setUpClass(mongo_client_class=mongomock.MongoClient)

tox.ini

@@ -31,13 +31,17 @@ DATABASE_TYPE =
 [testenv]
 passenv =
     MONGO_HOST
+    MONGO_USE_MOCK
     POSTGRES_HOST
     POSTGRES_DATABASE
 deps =
     mypy
     alchemy: SQLAlchemy
     alchemy: sqlalchemy_utils
     mongo: mongoengine
+    mongo: mongomock
+    # mongomock imports pkg_resources, provided by setuptools.
+    mongo: setuptools>=66.1.1
     django{32,42,50,main}: Pillow
     django32: Django>=3.2,<3.3
     django42: Django>=4.2,<5.0