django/tests/utils_tests/test_regex_helper.py

import re
import unittest

from django.test import SimpleTestCase
from django.utils import regex_helper


class NormalizeTests(unittest.TestCase):
    def test_empty(self):
        pattern = r""
        expected = [('', [])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)

    def test_escape(self):
        pattern = r"\\\^\$\.\|\?\*\+\(\)\["
        expected = [('\\^$.|?*+()[', [])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)

    def test_group_positional(self):
        pattern = r"(.*)-(.+)"
        expected = [('%(_0)s-%(_1)s', ['_0', '_1'])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)

    def test_group_noncapturing(self):
        pattern = r"(?:non-capturing)"
        expected = [('non-capturing', [])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)

    def test_group_named(self):
        pattern = r"(?P<first_group_name>.*)-(?P<second_group_name>.*)"
        expected = [('%(first_group_name)s-%(second_group_name)s',
                    ['first_group_name', 'second_group_name'])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)

    def test_group_backreference(self):
        pattern = r"(?P<first_group_name>.*)-(?P=first_group_name)"
        expected = [('%(first_group_name)s-%(first_group_name)s',
                    ['first_group_name'])]
        result = regex_helper.normalize(pattern)
        self.assertEqual(result, expected)


class LazyReCompileTests(SimpleTestCase):
    def test_flags_with_pre_compiled_regex(self):
        test_pattern = re.compile('test')
        lazy_test_pattern = regex_helper._lazy_re_compile(test_pattern, re.I)
        msg = 'flags must be empty if regex is passed pre-compiled'
        with self.assertRaisesMessage(AssertionError, msg):
            lazy_test_pattern.match('TEST')