Check for _id property in subdocument

If a subdocument contains an _id property, do not treat it as a
reference/relationship, instead ignore the _id property as the
_id from the root level document should take precedence. See #56

mongo_connector/doc_managers/nodes_and_relationships_builder.py

@@ -52,6 +52,11 @@ def build_node_with_reference(self, root_type, key, doc_id, document_key):
     if document_key is None:
       return
     doc_type = key.split("_id")[0]
+
+    # ignore _id property of subdocuments
+    if not doc_type or doc_type == "":
+      return
+
     parameters = {'_id':document_key}
     statement = "MERGE (d:Document:`{doc_type}` {{ _id: {{parameters}}._id}})".format(doc_type=doc_type)
     self.query_nodes.update({statement: {"parameters":parameters}})

tests/test_neo4j.py

@@ -30,6 +30,9 @@ def setUpClass(cls):
     cls.docman = DocManager('http://localhost:7474/db/data', auto_commit_interval=0)
 
   def _count(cls):
+    """
+    Return the number of nodes in the graph
+    """
     return cls.neo4j_conn.order
 
   def query(cls):
@@ -93,6 +96,34 @@ def test_insert(self):
       self.assertEqual(result_set_1['name'], result_set_2['name'])
       self.connector.doc_managers[0].graph.delete_all()
 
+    def test_subdocument_with_id(self):
+      """
+      Test inserting a document with a subdocument containing an _id property.
+      In the current version of translating from document data model to property graph, the root level _id
+      field is included in all subdocument nodes in the graph. This test verifies there is no error when
+      inserting a document containing a subdocument with an _id property.
+
+      See https://github.com/neo4j-contrib/neo4j_doc_manager/issues/56
+
+      """
+
+      doc = {
+        '_id': 'root_level_object_id',
+        'name': 'Bob',
+        'location': {
+          '_id': 'sub_document_object_id',
+          'city': 'Missoula',
+          'state': 'Montana'
+        }
+      }
+
+      self.connector.doc_managers[0].upsert(doc, "test.test_id", 1)
+      assert_soon(lambda: self._count() > 0)
+      result_set = self.neo4j_conn.find_one("location")
+      self.assertNotEqual(result_set, None)
+      self.assertEqual(result_set['_id'], 'root_level_object_id') # expect subdocument _id to be ignored
+
+
     def test_remove(self):
       """Tests remove operations."""
       self.conn['test']['test'].insert({'name': 'paulie'})