import re, doctest, unittest

from django.db import transaction

from django.core import management

from django.db.models import get_apps

normalize_long_ints = lambda s: re.sub(r'(?<![\w])(\d+)L(?![\w])', '\\1', s)

class OutputChecker(doctest.OutputChecker):

    def check_output(self, want, got, optionflags):

        ok = doctest.OutputChecker.check_output(self, want, got, optionflags)

        # Doctest does an exact string comparison of output, which means long

        # integers aren't equal to normal integers ("22L" vs. "22"). The

        # following code normalizes long integers so that they equal normal

        # integers.

        if not ok:

            return normalize_long_ints(want) == normalize_long_ints(got)

        return ok

class DocTestRunner(doctest.DocTestRunner):

    def __init__(self, *args, **kwargs):

        doctest.DocTestRunner.__init__(self, *args, **kwargs)

        self.optionflags = doctest.ELLIPSIS

    def report_unexpected_exception(self, out, test, example, exc_info):

        doctest.DocTestRunner.report_unexpected_exception(self,out,test,example,exc_info)

        # Rollback, in case of database errors. Otherwise they'd have

        # side effects on other tests.

        from django.db import transaction

        transaction.rollback_unless_managed()

class TestCase(unittest.TestCase):    

    def install_fixtures(self):

        """If the Test Case class has a 'fixtures' member, clear the database and

        install the named fixtures at the start of each test.

        """

        management.flush(verbosity=0, interactive=False)

        if hasattr(self, 'fixtures'):

            management.load_data(self.fixtures, verbosity=0)

    def run(self, result=None):

        """Wrapper around default run method so that user-defined Test Cases 

        automatically call install_fixtures without having to include a call to 

        super().

        """

        self.install_fixtures()

        super(TestCase, self).run(result)