Fix redaction tests

tests/conftest.py

@@ -0,0 +1,29 @@
+import pytest
+from django.conf import settings
+
+from tests.anon import UserAnonymiser
+from tests.models import User
+
+IS_POSTGRES = (
+    not settings.DATABASES["default"]["ENGINE"].endswith("postgresql"),
+    "PostgreSQL only",
+)
+
+
+@pytest.fixture
+def user() -> User:
+    return User.objects.create_user(
+        username="testuser1", first_name="fred", last_name="flintstone"
+    )
+
+
+@pytest.fixture
+def user2() -> User:
+    return User.objects.create_user(
+        username="testuser2", first_name="ginger", last_name="rogers"
+    )
+
+
+@pytest.fixture
+def user_anonymiser() -> UserAnonymiser:
+    return UserAnonymiser()

tests/test_models.py

@@ -8,11 +8,6 @@
 from .models import User
 
 
-@pytest.fixture
-def user_anonymiser() -> UserAnonymiser:
-    return UserAnonymiser()
-
-
 def test_model_fields_summary(user_anonymiser: UserAnonymiser) -> None:
     assert user_anonymiser.get_model_field_summary() == [
         FieldSummaryData(User._meta.get_field("id"), False),
@@ -43,12 +38,6 @@ def test_model_fields_data(user_anonymiser: UserAnonymiser) -> None:
 
 @pytest.mark.django_db
 class TestAnonymisableUserModel:
-    @pytest.fixture
-    def user(self) -> User:
-        return User.objects.create_user(
-            username="testuser", first_name="fred", last_name="flintstone"
-        )
-
     def test_anonymise_not_implemented(
         self, user: User, user_anonymiser: UserAnonymiser
     ) -> None:
@@ -65,15 +54,15 @@ def test_anonymise_first_name_field(
     def test_anonymise(self, user: User, user_anonymiser: UserAnonymiser) -> None:
         assert user.first_name == "fred"
         assert user.last_name == "flintstone"
-        assert user.username == "testuser"
+        assert user.username == "testuser1"
         user_anonymiser.anonymise_object(user)
         assert user.first_name == "Anonymous"
         assert user.last_name == "flintstone"
-        assert user.username == "testuser"
+        assert user.username == "testuser1"
         user.refresh_from_db()
         assert user.first_name == "fred"
         assert user.last_name == "flintstone"
-        assert user.username == "testuser"
+        assert user.username == "testuser1"
 
     @mock.patch.object(UserAnonymiser, "post_anonymise_object")
     def test_post_anonymise_object(

tests/test_models_pg.py

@@ -0,0 +1,61 @@
+from unittest import SkipTest, mock
+
+import pytest
+from django.conf import settings
+from django.db import connection
+from django.db.backends.utils import CursorWrapper
+
+from anonymiser.db.expressions import GenerateUuid4
+
+from .anon import UserAnonymiser
+from .models import User
+
+# skip if we're using SQLite as it doesn't support UUIDs
+if settings.DATABASES["default"]["ENGINE"] == "django.db.backends.sqlite3":
+    # this will skip all tests in this file
+    raise SkipTest("Skipping Postgres tets as SQLite is being used.")
+
+
+@pytest.mark.django_db
+@mock.patch.object(CursorWrapper, "execute")
+def test_generate_uuid4(mock_execute: mock.MagicMock) -> None:
+    User.objects.update(uuid=GenerateUuid4())
+    assert (
+        mock_execute.call_args[0][0]
+        == 'UPDATE "tests_user" SET "uuid" = uuid_generate_v4()'
+    )
+
+
+@pytest.mark.django_db
+class TestPostgresRedaction:
+    @pytest.fixture(autouse=True)
+    def activate_postgresql_uuid(self) -> None:
+        """Activate the uuid-ossp extension in the test database."""
+        with connection.cursor() as cursor:
+            cursor.execute('CREATE EXTENSION IF NOT EXISTS "uuid-ossp";')
+
+    def test_redact_queryset_none(
+        self, user: User, user_anonymiser: UserAnonymiser
+    ) -> None:
+        assert user_anonymiser.redact_queryset(User.objects.none()) == 0
+
+    def test_redact_queryset_one(
+        self, user: User, user_anonymiser: UserAnonymiser
+    ) -> None:
+        uuid = user.uuid
+        assert user_anonymiser.redact_queryset(User.objects.all()) == 1
+        user.refresh_from_db()
+        assert user.first_name == user_anonymiser.field_redactions["first_name"]
+        assert user.uuid != uuid
+
+    def test_redact_queryset_two(
+        self,
+        user: User,
+        user2: User,
+        user_anonymiser: UserAnonymiser,
+    ) -> None:
+        assert user_anonymiser.redact_queryset(User.objects.all()) == 2
+        user.refresh_from_db()
+        user2.refresh_from_db()
+        # confirm that we haven't reused the same uuid for all objects
+        assert user.uuid != user2.uuid