v11.6.0 (#39)

CHANGES.md

@@ -1,5 +1,8 @@
 # Changelog
 
+**11.6.0** (2024-11-20)
+  * Added `detect_ghost_tables` management command
+
 **11.5.5** (2024-11-20)
   * Moved permission check to "apps.ready()" method
   * Internal updates via `ambient-package-update`

ambient_toolbox/__init__.py

@@ -1,3 +1,3 @@
 """Python toolbox of Ambient Digital containing an abundance of useful tools and gadgets."""
 
-__version__ = "11.5.5"
+__version__ = "11.6.0"

ambient_toolbox/management/commands/detect_ghost_tables.py

@@ -0,0 +1,24 @@
+import sys
+
+from django.core.management.base import BaseCommand
+from django.db import connection
+
+
+class Command(BaseCommand):
+    """
+    Script to detect ghost tables.
+    Ghost tables are tables which were probably created by Django,
+    removed in the codebase but never removed in the database.
+    """
+
+    def handle(self, *args, **options):
+        table_names = set(connection.introspection.table_names())
+        django_table_names = set(connection.introspection.django_table_names())
+        possible_matches = table_names - django_table_names - {"django_migrations"}
+
+        if len(possible_matches) == 0:
+            return
+
+        sys.stdout.write("The following tables might be left-overs and can be deleted:\n")
+        for table in possible_matches:
+            sys.stdout.write(f"* {table}\n")

docs/features/cleanup.md

@@ -0,0 +1,16 @@
+# Clean-up
+
+## Detect "forgotten" tables
+
+Forgotten or ghost tables are tables which were created by Django migrations but then removed in the code. Django will
+not necessarily remove tables when deleting models. Adam Johnson wrote
+a [neat snippet](https://adamj.eu/tech/2024/11/21/django-tables-without-models/) to detect such tables.
+
+This package provides a management command to neatly list those tables in the command-line.
+
+```shell
+python ./manage.py detect_ghost_tables
+
+> The following tables might be left-overs and can be deleted:
+> * invalid_table
+```

docs/index.rst

@@ -16,6 +16,7 @@ The package is published at pypi under the following link: `https://pypi.org/pro
 
    features/setup.md
    features/admin.md
+   features/cleanup.md
    features/context_manager.md
    features/context_processors.md
    features/database_anonymisation.md

tests/management/commands/test_detect_ghost_tables.py

@@ -0,0 +1,22 @@
+import sys
+from unittest import mock
+
+from django.core.management import call_command
+from django.db import connection
+from django.test import SimpleTestCase
+
+
+class DetectGhostTableCommandTest(SimpleTestCase):
+    @mock.patch.object(connection.introspection, "table_names", return_value=["invalid_table"])
+    def test_management_command_match_found(self, *args):
+        with mock.patch.object(sys.stdout, "write") as mocked_write:
+            call_command("detect_ghost_tables")
+
+        mocked_write.assert_called_with("* invalid_table\n")
+
+    @mock.patch.object(connection.introspection, "table_names", return_value=[])
+    def test_management_no_match_found(self, *args):
+        with mock.patch.object(sys.stdout, "write") as mocked_write:
+            call_command("detect_ghost_tables")
+
+        mocked_write.assert_not_called()