Unit testing Postgis version check

import unittest

from django.contrib.gis.db.backends.postgis.operations import PostGISOperations

from django.core.exceptions import ImproperlyConfigured

from django.db import ProgrammingError

class FakeConnection(object):

    def __init__(self):

        self.settings_dict = {

            'NAME': 'test',

        }

class FakePostGISOperations(PostGISOperations):

    def __init__(self, version=None):

        self.version = version

        self.connection = FakeConnection()

    def _get_postgis_func(self, func):

        if func == 'postgis_lib_version':

            if self.version is None:

                raise ProgrammingError

            else:

                return self.version

        else:

            raise NotImplementedError('This function was not expected to be called')

class TestPostgisVersionCheck(unittest.TestCase):

    """

    Tests that the postgis version check parses correctly the version numbers

    """

    def test_get_version(self):

        expect = '1.0.0'

        ops = FakePostGISOperations(expect)

        actual = ops.postgis_lib_version()

        self.assertEqual(expect, actual)

    def test_version_classic_tuple(self):

        expect = ('1.2.3', 1, 2, 3)

        ops = FakePostGISOperations(expect[0])

        actual = ops.postgis_version_tuple()

        self.assertEqual(expect, actual)

    def test_version_dev_tuple(self):

        expect = ('1.2.3dev', 1, 2, 3)

        ops = FakePostGISOperations(expect[0])

        actual = ops.postgis_version_tuple()

        self.assertEqual(expect, actual)

    def test_valid_version_numbers(self):

        versions = [

            ('1.3.0', 1, 3, 0),

            ('2.1.1', 2, 1, 1),

            ('2.2.0dev', 2, 2, 0),

        ]

        for version in versions:

            ops = FakePostGISOperations(version[0])

            actual = ops.spatial_version

            self.assertEqual(version[1:], actual)

    def test_invalid_version_numbers(self):

        versions = ['nope', '123']

        for version in versions:

            ops = FakePostGISOperations(version)

            self.assertRaises(Exception, lambda: ops.spatial_version)

    def test_no_version_number(self):

        ops = FakePostGISOperations()

        self.assertRaises(ImproperlyConfigured, lambda: ops.spatial_version)