googleapis
diff --git a/noxfile.py b/noxfile.py
@@ -66,7 +66,12 @@ def lint_setup_py(session):
 def default(session):
     # Install all test dependencies, then install this package in-place.
     session.install(
-        "django~=2.2", "mock", "mock-import", "pytest", "pytest-cov"
+        "django~=2.2",
+        "mock",
+        "mock-import",
+        "pytest",
+        "pytest-cov",
+        "coverage",
     )
     session.install("-e", ".")
 
@@ -79,7 +84,7 @@ def default(session):
         "--cov-append",
         "--cov-config=.coveragerc",
         "--cov-report=",
-        "--cov-fail-under=20",
+        "--cov-fail-under=68",
         os.path.join("tests", "unit"),
         *session.posargs
     )

diff --git a/tests/conftest.py b/tests/conftest.py
@@ -0,0 +1,13 @@
+import os
+import django
+from django.conf import settings
+
+# We manually designate which settings we will be using in an environment
+# variable. This is similar to what occurs in the `manage.py` file.
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "tests.settings")
+
+
+# `pytest` automatically calls this function once when tests are run.
+def pytest_configure():
+    settings.DEBUG = False
+    django.setup()
diff --git a/tests/settings.py b/tests/settings.py
@@ -0,0 +1,46 @@
+# Copyright 2021 Google LLC
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+DEBUG = True
+USE_TZ = True
+
+INSTALLED_APPS = [
+    "django_spanner",  # Must be the first entry
+    "django.contrib.contenttypes",
+    "django.contrib.auth",
+    "django.contrib.sites",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "tests",
+]
+
+TIME_ZONE = "UTC"
+
+DATABASES = {
+    "default": {
+        "ENGINE": "django_spanner",
+        "PROJECT": "emulator-local",
+        "INSTANCE": "django-test-instance",
+        "NAME": "django-test-db",
+    }
+}
+SECRET_KEY = "spanner emulator secret key"
+
+PASSWORD_HASHERS = [
+    "django.contrib.auth.hashers.MD5PasswordHasher",
+]
+
+SITE_ID = 1
+
+CONN_MAX_AGE = 60
+
+ENGINE = "django_spanner"
+PROJECT = "emulator-local"
+INSTANCE = "django-test-instance"
+NAME = "django-test-db"
+OPTIONS = {}
+AUTOCOMMIT = True
diff --git a/tests/unit/django_spanner/__init__.py b/tests/unit/django_spanner/__init__.py
diff --git a/tests/unit/django_spanner/models.py b/tests/unit/django_spanner/models.py
@@ -0,0 +1,61 @@
+# Copyright 2021 Google LLC
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+"""
+Different models used for testing django-spanner code.
+"""
+from django.db import models
+
+
+# Register transformations for model fields.
+class UpperCase(models.Transform):
+    lookup_name = "upper"
+    function = "UPPER"
+    bilateral = True
+
+
+models.CharField.register_lookup(UpperCase)
+models.TextField.register_lookup(UpperCase)
+
+
+# Models
+class ModelDecimalField(models.Model):
+    field = models.DecimalField()
+
+
+class ModelCharField(models.Model):
+    field = models.CharField()
+
+
+class Item(models.Model):
+    item_id = models.IntegerField()
+    name = models.CharField(max_length=10)
+    created = models.DateTimeField()
+    modified = models.DateTimeField(blank=True, null=True)
+
+    class Meta:
+        ordering = ["name"]
+
+
+class Number(models.Model):
+    num = models.IntegerField()
+    decimal_num = models.DecimalField(max_digits=5, decimal_places=2)
+    item = models.ForeignKey(Item, models.CASCADE)
+
+
+class Author(models.Model):
+    name = models.CharField(max_length=40)
+    last_name = models.CharField(max_length=40)
+    num = models.IntegerField(unique=True)
+    created = models.DateTimeField()
+    modified = models.DateTimeField(blank=True, null=True)
+
+
+class Report(models.Model):
+    name = models.CharField(max_length=10)
+    creator = models.ForeignKey(Author, models.CASCADE, null=True)
+
+    class Meta:
+        ordering = ["name"]
diff --git a/tests/unit/django_spanner/simple_test.py b/tests/unit/django_spanner/simple_test.py
@@ -0,0 +1,33 @@
+# Copyright 2021 Google LLC
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+from django_spanner.client import DatabaseClient
+from django_spanner.base import DatabaseWrapper
+from django_spanner.operations import DatabaseOperations
+from unittest import TestCase
+import os
+
+
+class SpannerSimpleTestClass(TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.PROJECT = os.environ["GOOGLE_CLOUD_PROJECT"]
+
+        cls.INSTANCE_ID = "instance_id"
+        cls.DATABASE_ID = "database_id"
+        cls.USER_AGENT = "django_spanner/2.2.0a1"
+        cls.OPTIONS = {"option": "dummy"}
+
+        cls.settings_dict = {
+            "PROJECT": cls.PROJECT,
+            "INSTANCE": cls.INSTANCE_ID,
+            "NAME": cls.DATABASE_ID,
+            "user_agent": cls.USER_AGENT,
+            "OPTIONS": cls.OPTIONS,
+        }
+        cls.db_client = DatabaseClient(cls.settings_dict)
+        cls.db_wrapper = cls.connection = DatabaseWrapper(cls.settings_dict)
+        cls.db_operations = DatabaseOperations(cls.connection)
diff --git a/tests/unit/django_spanner/test_base.py b/tests/unit/django_spanner/test_base.py
@@ -4,59 +4,24 @@
 # license that can be found in the LICENSE file or at
 # https://developers.google.com/open-source/licenses/bsd
 
-import sys
-import unittest
-import os
-
-from mock_import import mock_import
 from unittest import mock
+from tests.unit.django_spanner.simple_test import SpannerSimpleTestClass
 
 
-@mock_import()
-@unittest.skipIf(
-    sys.version_info < (3, 6), reason="Skipping Python versions <= 3.5"
-)
-class TestBase(unittest.TestCase):
-    PROJECT = os.environ["GOOGLE_CLOUD_PROJECT"]
-    INSTANCE_ID = "instance_id"
-    DATABASE_ID = "database_id"
-    USER_AGENT = "django_spanner/2.2.0a1"
-    OPTIONS = {"option": "dummy"}
-
-    settings_dict = {
-        "PROJECT": PROJECT,
-        "INSTANCE": INSTANCE_ID,
-        "NAME": DATABASE_ID,
-        "user_agent": USER_AGENT,
-        "OPTIONS": OPTIONS,
-    }
-
-    def _get_target_class(self):
-        from django_spanner.base import DatabaseWrapper
-
-        return DatabaseWrapper
-
-    def _make_one(self, *args, **kwargs):
-        return self._get_target_class()(*args, **kwargs)
-
+class TestBase(SpannerSimpleTestClass):
     def test_property_instance(self):
-        settings_dict = {"INSTANCE": "instance"}
-        db_wrapper = self._make_one(settings_dict=settings_dict)
-
         with mock.patch("django_spanner.base.spanner") as mock_spanner:
             mock_spanner.Client = mock_client = mock.MagicMock()
             mock_client().instance = mock_instance = mock.MagicMock()
-            _ = db_wrapper.instance
-            mock_instance.assert_called_once_with(settings_dict["INSTANCE"])
+            _ = self.db_wrapper.instance
+            mock_instance.assert_called_once_with(self.INSTANCE_ID)
 
-    def test_property__nodb_connection(self):
-        db_wrapper = self._make_one(None)
+    def test_property_nodb_connection(self):
         with self.assertRaises(NotImplementedError):
-            db_wrapper._nodb_connection()
+            self.db_wrapper._nodb_connection()
 
     def test_get_connection_params(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        params = db_wrapper.get_connection_params()
+        params = self.db_wrapper.get_connection_params()
 
         self.assertEqual(params["project"], self.PROJECT)
         self.assertEqual(params["instance_id"], self.INSTANCE_ID)
@@ -65,54 +30,50 @@ def test_get_connection_params(self):
         self.assertEqual(params["option"], self.OPTIONS["option"])
 
     def test_get_new_connection(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.Database = mock_database = mock.MagicMock()
+        self.db_wrapper.Database = mock_database = mock.MagicMock()
         mock_database.connect = mock_connection = mock.MagicMock()
         conn_params = {"test_param": "dummy"}
-        db_wrapper.get_new_connection(conn_params)
+        self.db_wrapper.get_new_connection(conn_params)
         mock_connection.assert_called_once_with(**conn_params)
 
     def test_init_connection_state(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.connection = mock_connection = mock.MagicMock()
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.close = mock_close = mock.MagicMock()
-        db_wrapper.init_connection_state()
+        self.db_wrapper.init_connection_state()
         mock_close.assert_called_once_with()
 
     def test_create_cursor(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.connection = mock_connection = mock.MagicMock()
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.cursor = mock_cursor = mock.MagicMock()
-        db_wrapper.create_cursor()
+        self.db_wrapper.create_cursor()
         mock_cursor.assert_called_once_with()
 
-    def test__set_autocommit(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.connection = mock_connection = mock.MagicMock()
+    def test_set_autocommit(self):
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.autocommit = False
-        db_wrapper._set_autocommit(True)
+        self.db_wrapper._set_autocommit(True)
         self.assertEqual(mock_connection.autocommit, True)
 
     def test_is_usable(self):
-        from google.cloud.spanner_dbapi.exceptions import Error
-
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.connection = None
-        self.assertFalse(db_wrapper.is_usable())
+        self.db_wrapper.connection = None
+        self.assertFalse(self.db_wrapper.is_usable())
 
-        db_wrapper.connection = mock_connection = mock.MagicMock()
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.is_closed = True
-        self.assertFalse(db_wrapper.is_usable())
+        self.assertFalse(self.db_wrapper.is_usable())
 
         mock_connection.is_closed = False
-        self.assertTrue(db_wrapper.is_usable())
+        self.assertTrue(self.db_wrapper.is_usable())
+
+    def test_is_usable_with_error(self):
+        from google.cloud.spanner_dbapi.exceptions import Error
 
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.cursor = mock.MagicMock(side_effect=Error)
-        self.assertFalse(db_wrapper.is_usable())
+        self.assertFalse(self.db_wrapper.is_usable())
 
-    def test__start_transaction_under_autocommit(self):
-        db_wrapper = self._make_one(self.settings_dict)
-        db_wrapper.connection = mock_connection = mock.MagicMock()
+    def test_start_transaction_under_autocommit(self):
+        self.db_wrapper.connection = mock_connection = mock.MagicMock()
         mock_connection.cursor = mock_cursor = mock.MagicMock()
-        db_wrapper._start_transaction_under_autocommit()
+        self.db_wrapper._start_transaction_under_autocommit()
         mock_cursor.assert_called_once_with()
diff --git a/tests/unit/django_spanner/test_client.py b/tests/unit/django_spanner/test_client.py
@@ -4,41 +4,12 @@
 # license that can be found in the LICENSE file or at
 # https://developers.google.com/open-source/licenses/bsd
 
-import sys
-import unittest
-import os
 
+from google.cloud.spanner_dbapi.exceptions import NotSupportedError
+from tests.unit.django_spanner.simple_test import SpannerSimpleTestClass
 
-@unittest.skipIf(
-    sys.version_info < (3, 6), reason="Skipping Python versions <= 3.5"
-)
-class TestClient(unittest.TestCase):
-    PROJECT = os.environ["GOOGLE_CLOUD_PROJECT"]
-    INSTANCE_ID = "instance_id"
-    DATABASE_ID = "database_id"
-    USER_AGENT = "django_spanner/2.2.0a1"
-    OPTIONS = {"option": "dummy"}
-
-    settings_dict = {
-        "PROJECT": PROJECT,
-        "INSTANCE": INSTANCE_ID,
-        "NAME": DATABASE_ID,
-        "user_agent": USER_AGENT,
-        "OPTIONS": OPTIONS,
-    }
-
-    def _get_target_class(self):
-        from django_spanner.client import DatabaseClient
-
-        return DatabaseClient
-
-    def _make_one(self, *args, **kwargs):
-        return self._get_target_class()(*args, **kwargs)
 
+class TestClient(SpannerSimpleTestClass):
     def test_runshell(self):
-        from google.cloud.spanner_dbapi.exceptions import NotSupportedError
-
-        db_wrapper = self._make_one(self.settings_dict)
-
         with self.assertRaises(NotSupportedError):
-            db_wrapper.runshell(parameters=self.settings_dict)
+            self.db_client.runshell(parameters=self.settings_dict)