Fixed wrong diff when same nodes but different links #36

netdiff/utils.py

@@ -20,14 +20,14 @@ def diff(old, new):
     changed_edges = _find_changed(old.graph, new.graph, in_both)
     # create netjson objects
     # or assign None if no changes
-    if added_nodes.nodes() and added_edges.edges():
+    if added_nodes.nodes() or added_edges.edges():
         added = _netjson_networkgraph(protocol, version, revision, metric,
                                       added_nodes.nodes(data=True),
                                       added_edges.edges(data=True),
                                       dict=True)
     else:
         added = None
-    if removed_nodes.nodes() and removed_edges.edges():
+    if removed_nodes.nodes() or removed_edges.edges():
         removed = _netjson_networkgraph(protocol, version, revision, metric,
                                         removed_nodes.nodes(data=True),
                                         removed_edges.edges(data=True),

tests/test_utils.py

@@ -0,0 +1,89 @@
+import os
+
+from netdiff import NetJsonParser
+from netdiff import diff
+from netdiff.tests import TestCase
+
+
+CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))
+links2 = '{0}/static/netjson-2-links.json'.format(CURRENT_DIR)
+
+
+class TestUtils(TestCase):
+    """ tests for netdiff.utils """
+
+    def test_same_nodes_but_added_links(self):
+        """
+        See issue 36:
+        https://github.com/ninuxorg/netdiff/issues/36
+        """
+        old = NetJsonParser({
+            "type": "NetworkGraph",
+            "protocol": "OLSR",
+            "version": "0.6.6",
+            "revision": "5031a799fcbe17f61d57e387bc3806de",
+            "metric": "ETX",
+            "nodes": [
+                {
+                    "id": "10.150.0.3",
+                    "local_addresses": ["192.168.1.3"],
+                    "properties": {"hostname": "router.3nnx"}
+                },
+                {
+                    "id": "10.150.0.2",
+                    "local_addresses": ["192.168.1.2"],
+                    "properties": {"hostname": "router2.nnx"}
+                },
+                {
+                    "id": "10.150.0.4",
+                    "local_addresses": ["192.168.1.3"],
+                    "properties": {"hostname": "router4.nnx"}
+                }
+            ],
+            "links": []
+        })
+        new = NetJsonParser(links2)
+        result = diff(old, new)
+        self.assertIsNone(result['removed'])
+        self.assertIsNone(result['changed'])
+        self.assertIsNotNone(result['added'])
+        self.assertEqual(len(result['added']['links']), 2)
+        self.assertEqual(len(result['added']['nodes']), 0)
+
+    def test_same_nodes_but_removed_links(self):
+        """
+        See issue 36:
+        https://github.com/ninuxorg/netdiff/issues/36
+        """
+        old = NetJsonParser({
+            "type": "NetworkGraph",
+            "protocol": "OLSR",
+            "version": "0.6.6",
+            "revision": "5031a799fcbe17f61d57e387bc3806de",
+            "metric": "ETX",
+            "nodes": [
+                {"id": "10.150.0.3"},
+                {"id": "10.150.0.2"}
+            ],
+            "links": [
+                {"source": "10.150.0.3", "target": "10.150.0.2", "cost": 1}
+            ]
+        })
+        new = NetJsonParser({
+            "type": "NetworkGraph",
+            "protocol": "OLSR",
+            "version": "0.6.6",
+            "revision": "5031a799fcbe17f61d57e387bc3806de",
+            "metric": "ETX",
+            "nodes": [
+                {"id": "10.150.0.3"},
+                {"id": "10.150.0.2"}
+            ],
+            "links": []
+        })
+        result = diff(old, new)
+        self.assertIsNone(result['changed'])
+        self.assertIsNone(result['added'])
+        self.assertIsNotNone(result['removed'])
+        self.assertEqual(len(result['removed']['nodes']), 0)
+        self.assertEqual(len(result['removed']['links']), 1)