fixed label issue for last node when hydrating relationship (#411)

Author: martin-neotech

neo4j/graph/__init__.py

@@ -84,7 +84,7 @@ def hydrate_node(self, n_id, n_labels=None, properties=None):
                 # a relationship, it won't have any labels or properties.
                 # Therefore, we need to add the ones we have here.
                 if n_labels:
-                    inst._labels = frozenset(inst._labels & set(n_labels))
+                    inst._labels = inst._labels.union(n_labels)  # frozen_set
                 if properties:
                     inst._properties.update(properties)
             return inst

tests/integration/test_result_graph.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+# -*- encoding: utf-8 -*-
+
+# Copyright (c) 2002-2020 "Neo4j,"
+# Neo4j Sweden AB [http://neo4j.com]
+#
+# This file is part of Neo4j.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import pytest
+
+from neo4j.graph import (
+    Node,
+    Relationship,
+    Graph,
+    Path,
+)
+from neo4j.exceptions import Neo4jError
+
+
+def test_result_graph_instance(session):
+    # python -m pytest tests/integration/test_result_graph.py -s -v -k test_result_graph_instance
+    result = session.run("RETURN 1")
+    graph = result.graph()
+
+    assert isinstance(graph, Graph)
+
+
+def test_result_graph_case_1(session):
+    # python -m pytest tests/integration/test_result_graph.py -s -v -k test_result_graph_case_1
+    result = session.run("CREATE (n1:Person:LabelTest1 {name:'Alice'})-[r1:KNOWS {since:1999}]->(n2:Person:LabelTest2 {name:'Bob'}) RETURN n1, r1, n2")
+    graph = result.graph()
+    assert isinstance(graph, Graph)
+
+    node_view = graph.nodes
+    relationships_view = graph.relationships
+
+    for node in node_view:
+        name = node["name"]
+        if name == "Alice":
+            assert node.labels == frozenset(["Person", "LabelTest1"])
+        elif name == "Bob":
+            assert node.labels == frozenset(["Person", "LabelTest2"])
+        else:
+            pytest.fail("should only contain 2 nodes, Alice and Bob. {}".format(name))
+
+    for relationship in relationships_view:
+        since = relationship["since"]
+        assert since == 1999
+        assert relationship.type == "KNOWS"