from unittest import mock

from django.db import connections, models

from django.test import SimpleTestCase

from django.test.utils import isolate_apps, override_settings

class TestRouter:

    """

    Routes to the 'other' database if the model name starts with 'Other'.

    """

    def allow_migrate(self, db, app_label, model_name=None, **hints):

        return db == ("other" if model_name.startswith("other") else "default")

@override_settings(DATABASE_ROUTERS=[TestRouter()])

@isolate_apps("check_framework")

class TestMultiDBChecks(SimpleTestCase):

    def _patch_check_field_on(self, db):

        return mock.patch.object(connections[db].validation, "check_field")

    def test_checks_called_on_the_default_database(self):

        class Model(models.Model):

            field = models.CharField(max_length=100)

        model = Model()

        with self._patch_check_field_on("default") as mock_check_field_default:

            with self._patch_check_field_on("other") as mock_check_field_other:

                model.check(databases={"default", "other"})

                self.assertTrue(mock_check_field_default.called)

                self.assertFalse(mock_check_field_other.called)

    def test_checks_called_on_the_other_database(self):

        class OtherModel(models.Model):

            field = models.CharField(max_length=100)

        model = OtherModel()

        with self._patch_check_field_on("other") as mock_check_field_other:

            with self._patch_check_field_on("default") as mock_check_field_default:

                model.check(databases={"default", "other"})

                self.assertTrue(mock_check_field_other.called)

                self.assertFalse(mock_check_field_default.called)