added pass criteria for juniper hostname derivation

test/test_junosspace_io.py

@@ -35,11 +35,20 @@ def test_junosspace_devices_parsing(data_config):
 
 
 def test_router_hostname_derivation(mocked_redis):
+    """
+    test result depends specifically on the test data set containing
+    a realistic snapshot
+
+    :param mocked_redis:
+    :return:
+    """
     config = {
         'redis': {
             'hostname': None,
             'port': None
         }
     }
-    for hostname in worker._derive_router_hostnames(config):
-        assert re.match('^mx[\d].+\.geant\.net$', hostname)
+    hostnames = list(worker._derive_router_hostnames(config))
+    assert hostnames  # test data is non-empty
+    for h in hostnames:
+        assert re.match(r'^mx[12].+\.geant\.net$', h)