firewall: create test for firewall.models.Vlan.get_new_address

fixes #17

circle/firewall/tests/test_firewall.py

 from django.test import TestCase
-from admin import HostAdmin
+from django.contrib.auth.models import User
+from ..admin import HostAdmin
+from firewall.models import Vlan, Domain, Host
+from django.forms import ValidationError
 
 
 class MockInstance:
@@ -36,3 +39,46 @@ class HostAdminTestCase(TestCase):
                                  MockGroup("korte"), MockGroup("szilva")])
         l = HostAdmin.list_groups(instance)
         self.assertEqual(l, "alma, korte, szilva")
+
+
+class GetNewAddressTestCase(TestCase):
+    def setUp(self):
+        self.u1 = User.objects.create(username='user1')
+        self.u1.save()
+        d = Domain(name='example.org', owner=self.u1)
+        d.save()
+        # /29 = .1-.6 =  6 hosts/subnet + broadcast + network id
+        self.vlan = Vlan(vid=1, name='test', network4='10.0.0.0/29',
+                         network6='2001:738:2001:4031::/80', domain=d,
+                         owner=self.u1)
+        self.vlan.save()
+        self.vlan.host_set.all().delete()
+        for i in [1] + range(3, 6):
+            Host(hostname='h-%d' % i, mac='01:02:03:04:05:%02d' % i,
+                 ipv4='10.0.0.%d' % i, vlan=self.vlan,
+                 owner=self.u1).save()
+
+    def test_new_addr_w_empty_vlan(self):
+        self.vlan.host_set.all().delete()
+        self.vlan.get_new_address()
+
+    def test_all_addr_in_use(self):
+        for i in (2, 6):
+            Host(hostname='h-%d' % i, mac='01:02:03:04:05:%02d' % i,
+                 ipv4='10.0.0.%d' % i, vlan=self.vlan,
+                 owner=self.u1).save()
+        self.assertRaises(ValidationError, self.vlan.get_new_address)
+
+    def test_all_addr_in_use_w_ipv6(self):
+        Host(hostname='h-x', mac='01:02:03:04:05:06',
+             ipv4='10.0.0.6', ipv6='2001:738:2001:4031:0:0:2:0',
+             vlan=self.vlan, owner=self.u1).save()
+        self.assertRaises(ValidationError, self.vlan.get_new_address)
+
+    def test_new_addr_last(self):
+        self.assertEqual(self.vlan.get_new_address()['ipv4'], '10.0.0.6')
+
+    def test_new_addr_w_overflow(self):
+        Host(hostname='h-6', mac='01:02:03:04:05:06',
+             ipv4='10.0.0.6', vlan=self.vlan, owner=self.u1).save()
+        self.assertEqual(self.vlan.get_new_address()['ipv4'], '10.0.0.2')