[1.8.x] Improved isolation of applied-migrations table in migration tests.

import os

from django.db import connection

from django.db.migrations.recorder import MigrationRecorder

from django.test import TransactionTestCase

from django.utils._os import upath

    available_apps = ["migrations"]

    test_dir = os.path.abspath(os.path.dirname(upath(__file__)))

    def tearDown(self):

        # Reset applied-migrations state.

        recorder = MigrationRecorder(connection)

        recorder.migration_qs.filter(app='migrations').delete()

    def get_table_description(self, table):

        with connection.cursor() as cursor:

            return connection.introspection.get_table_description(cursor, table)