add warnings and RunPython basic linting

tests/fixtures.py

@@ -10,3 +10,4 @@ ALTER_COLUMN = "app_alter_column"
 ALTER_COLUMN_DROP_NOT_NULL = "app_alter_column_drop_not_null"
 DROP_UNIQUE_TOGETHER = "app_unique_together"
 ADD_MANYTOMANY_FIELD = "app_add_manytomany_field"
+DATA_MIGRATIONS = "app_data_migrations"

tests/functional/test_data_migrations.py

@@ -0,0 +1,36 @@
+import os
+import unittest
+
+from django.conf import settings
+
+from django_migration_linter import MigrationLinter
+from tests import fixtures
+
+
+class DataMigrationDetectionTestCase(unittest.TestCase):
+    def setUp(self, *args, **kwargs):
+        self.test_project_path = os.path.dirname(settings.BASE_DIR)
+        self.linter = MigrationLinter(
+            self.test_project_path,
+            include_apps=fixtures.DATA_MIGRATIONS,
+        )
+
+    def test_reverse_data_migration(self):
+        self.assertEqual(0, self.linter.nb_warnings)
+        reverse_migration = self.linter.migration_loader.disk_migrations[
+            ("app_data_migrations", "0002_missing_reverse")
+        ]
+        self.linter.lint_migration(reverse_migration)
+
+        self.assertEqual(1, self.linter.nb_warnings)
+        self.assertFalse(self.linter.has_errors)
+
+    def test_reverse_data_migration_ignore(self):
+        self.assertEqual(0, self.linter.nb_warnings)
+        reverse_migration = self.linter.migration_loader.disk_migrations[
+            ("app_data_migrations", "0003_incorrect_arguments")
+        ]
+        self.linter.lint_migration(reverse_migration)
+
+        self.assertEqual(1, self.linter.nb_warnings)
+        self.assertFalse(self.linter.has_errors)

tests/test_project/settings.py

@@ -53,6 +53,7 @@ INSTALLED_APPS = [
     "tests.test_project.app_rename_column",
     "tests.test_project.app_rename_table",
     "tests.test_project.app_unique_together",
+    "tests.test_project.app_data_migrations",
 ]
 
 MIDDLEWARE = [