Refs #31055 -- Augmented regression tests for database system checks.

We might want to change this in the future but it should be further
discussed first.

tests/check_framework/tests.py

@@ -1,11 +1,11 @@
 import multiprocessing
 import sys
 from io import StringIO
-from unittest import skipIf
+from unittest import mock, skipIf
 
 from django.apps import apps
 from django.core import checks
-from django.core.checks import Error, Warning
+from django.core.checks import Error, Tags, Warning
 from django.core.checks.messages import CheckMessage
 from django.core.checks.registry import CheckRegistry
 from django.core.management import call_command
@@ -268,6 +268,18 @@ class CheckCommandTests(SimpleTestCase):
         with self.assertRaises(CommandError):
             call_command("check", fail_level="WARNING")
 
+    def test_database_system_checks(self):
+        database_check = mock.Mock(return_value=[], tags=[Tags.database])
+
+        with override_system_checks([database_check]):
+            call_command("check")
+            database_check.assert_called_once_with(app_configs=None, databases=None)
+            database_check.reset_mock()
+            call_command("check", databases=["default"])
+            database_check.assert_called_once_with(
+                app_configs=None, databases=["default"]
+            )
+
 
 def custom_error_system_check(app_configs, **kwargs):
     return [Error("Error", id="myerrorcheck.E001")]

tests/migrations/test_commands.py

@@ -113,7 +113,7 @@ class MigrateTests(MigrationTestBase):
         out = io.StringIO()
         call_command("migrate", skip_checks=False, no_color=True, stdout=out)
         self.assertIn("Apply all migrations: migrated_app", out.getvalue())
-        mocked_check.assert_called_once()
+        mocked_check.assert_called_once_with(databases=["default"])
 
     def test_migrate_with_custom_system_checks(self):
         original_checks = registry.registered_checks.copy()
@@ -137,6 +137,25 @@ class MigrateTests(MigrationTestBase):
         command = CustomMigrateCommandWithSecurityChecks()
         call_command(command, skip_checks=False, stdout=io.StringIO())
 
+    @override_settings(
+        INSTALLED_APPS=[
+            "django.contrib.auth",
+            "django.contrib.contenttypes",
+            "migrations.migrations_test_apps.migrated_app",
+        ]
+    )
+    def test_migrate_runs_database_system_checks(self):
+        original_checks = registry.registered_checks.copy()
+        self.addCleanup(setattr, registry, "registered_checks", original_checks)
+
+        out = io.StringIO()
+        mock_check = mock.Mock(return_value=[])
+        register(mock_check, Tags.database)
+
+        call_command("migrate", skip_checks=False, no_color=True, stdout=out)
+        self.assertIn("Apply all migrations: migrated_app", out.getvalue())
+        mock_check.assert_called_once_with(app_configs=None, databases=["default"])
+
     @override_settings(
         INSTALLED_APPS=[
             "migrations",