Adds check to forbid auto-names for migrations

README.md

@@ -12,6 +12,7 @@
 - Allows to test `django` schema and data migrations
 - Allows to test both forward and rollback migrations
 - Allows to test the migrations order
+- Allows to test migration names
 - Fully typed with annotations and checked with `mypy`, [PEP561 compatible](https://www.python.org/dev/peps/pep-0561/)
 - Easy to start: has lots of docs, tests, and tutorials
 
@@ -136,7 +137,7 @@ assert nodes_to_tuples(main_migrations) == [
     ('main_app', '0001_initial'),
     ('main_app', '0002_someitem_is_clean'),
     ('other_app', '0001_initial'),
-    ('main_app', '0003_auto_20191119_2125'),
+    ('main_app', '0003_update_is_clean'),
     ('main_app', '0004_auto_20191119_2125'),
     ('other_app', '0002_auto_20191120_2230'),
 ]
@@ -193,7 +194,7 @@ class TestDirectMigration(MigratorTestCase):
     """This class is used to test direct migrations."""
 
     migrate_from = ('main_app', '0002_someitem_is_clean')
-    migrate_to = ('main_app', '0003_auto_20191119_2125')
+    migrate_to = ('main_app', '0003_update_is_clean')
 
     def prepare(self):
         """Prepare some data before the migration."""
@@ -210,13 +211,47 @@ class TestDirectMigration(MigratorTestCase):
 ```
 
 
+## Testing migration names
+
+`django` generates migration names for you when you run `makemigrations`.
+And these names are bad ([read more](https://adamj.eu/tech/2020/02/24/how-to-disallow-auto-named-django-migrations/) about why it is bad)!
+Just look at this: `0004_auto_20191119_2125.py`
+
+What does this migration do? What changes does it have?
+
+One can also pass `--name` attribute when creating migrations, but it is easy to forget.
+
+We offer an automated solution: `django` check
+that produces a warning for each badly named migration.
+
+Add our check into your `INSTALLED_APPS`:
+
+```python
+INSTALLED_APPS = [
+    # ...
+
+    # Our custom check:
+    'django_test_migrations.contrib.django_checks.AutoNames',
+]
+```
+
+And then in your CI run:
+
+```bash
+python manage.py check --deploy --fail-level WARNING
+```
+
+This way you will be safe from wrong names in your migrations.
+
+
 ## Credits
 
 This project is based on work of other awesome people:
 
 - [@asfaltboy](https://gist.github.com/asfaltboy/b3e6f9b5d95af8ba2cc46f2ba6eae5e2)
 - [@blueyed](https://gist.github.com/blueyed/4fb0a807104551f103e6)
 - [@fernandogrd](https://gist.github.com/blueyed/4fb0a807104551f103e6#gistcomment-1546191)
+- [@@adamchainz](https://adamj.eu/tech/2020/02/24/how-to-disallow-auto-named-django-migrations/)
 
 ## License
 

django_test_app/django_test_app/settings.py

@@ -42,6 +42,9 @@
     'django.contrib.messages',
     'django.contrib.staticfiles',
 
+    # Our custom check:
+    'django_test_migrations.contrib.django_checks.AutoNames',
+
     # Custom:
     'main_app',
 ]

django_test_app/main_app/migrations/0004_auto_20191119_2125.py

@@ -1,14 +1,21 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 2.2.7 on 2019-11-19 21:25
 
+"""
+This migration is named incorrectly.
+
+We use it as a test for wrong autonames.
+Please, do not rename it!
+"""
+
 from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
     """Removes the default value from ``is_clean`` from ``SomeItem``."""
 
     dependencies = [
-        ('main_app', '0003_auto_20191119_2125'),
+        ('main_app', '0003_update_is_clean'),
     ]
 
     operations = [

django_test_migrations/autonames.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+
+from fnmatch import fnmatch
+from typing import List, Set, Tuple
+
+from django.conf import settings
+from django.core.checks import CheckMessage, Warning
+from django.db.migrations.loader import MigrationLoader
+from typing_extensions import Final
+
+#: We use this value as a unique identifier of this check.
+CHECK_NAME: Final = 'django_test_migrations.autonames'
+
+#: Settings name for this check to ignore some migrations.
+_SETTINGS_NAME: Final = 'DTM_IGNORED_MIGRATIONS'
+
+
+def check_migration_names(*args, **kwargs) -> List[CheckMessage]:
+    """Finds automatic names in available migrations."""
+    loader = MigrationLoader(None, ignore_no_migrations=True)
+    loader.load_disk()
+
+    ignored_migrations: Set[Tuple[str, str]] = getattr(
+        settings, _SETTINGS_NAME, set(),
+    )
+
+    messages = []
+    for app_label, migration_name in loader.disk_migrations.keys():
+        if (app_label, migration_name) in ignored_migrations:
+            continue
+
+        if fnmatch(migration_name, '????_auto_*'):
+            messages.append(
+                Warning(
+                    'Migration {0}.{1} has an automatic name.'.format(
+                        app_label, migration_name,
+                    ),
+                    hint=(
+                        'Rename the migration to describe its contents, ' +
+                        "or if it's from a third party app, add to " +
+                        _SETTINGS_NAME
+                    ),
+                    id='{0}.E001'.format(CHECK_NAME),
+                ),
+            )
+    return messages

django_test_migrations/contrib/django_checks.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+
+from django.apps import AppConfig
+from django.core import checks
+
+from django_test_migrations.autonames import CHECK_NAME, check_migration_names
+
+
+class AutoNames(AppConfig):
+    """
+    Class to install this check into ``INSTALLED_APPS`` in ``django``.
+
+    See:
+        https://docs.djangoproject.com/en/3.0/ref/applications/
+
+    """
+
+    name = CHECK_NAME
+
+    def ready(self):
+        """That's how we register our check when apps are ready."""
+        checks.register(checks.Tags.compatibility)(check_migration_names)