Add tests for update query with blank nodes

- check if the bnode is parsed correctly from the query
- check of the bnode is serialized to ntriples correctly after an update
and if it can be parsed again
- add these two tests for the SPARQL store and the inmemory Graph()

test/test_sparql.py

@@ -1,4 +1,4 @@
-from rdflib import Graph, URIRef, Literal
+from rdflib import Graph, URIRef, Literal, BNode
 from rdflib.plugins.sparql import prepareQuery
 from rdflib.compare import isomorphic
 
@@ -79,6 +79,35 @@ def test_complex_sparql_construct():
     g.query(q)
 
 
+def test_sparql_update_with_bnode():
+    """
+    Test if the blank node is inserted correctly.
+    """
+    graph = Graph()
+    graph.update(
+        "INSERT DATA { _:blankA <urn:type> <urn:Blank> }")
+    for t in graph.triples((None, None, None)):
+        assert isinstance(t[0], BNode)
+        eq_(t[1].n3(), "<urn:type>")
+        eq_(t[2].n3(), "<urn:Blank>")
+
+
+def test_sparql_update_with_bnode_serialize_parse():
+    """
+    Test if the blank node is inserted correctly, can be serialized and parsed.
+    """
+    graph = Graph()
+    graph.update(
+        "INSERT DATA { _:blankA <urn:type> <urn:Blank> }")
+    string = graph.serialize(format='ntriples').decode('utf-8')
+    raised = False
+    try:
+        Graph().parse(data=string, format="ntriples")
+    except Exception as e:
+        raised = True
+    assert not raised
+
+
 if __name__ == '__main__':
     import nose
     nose.main(defaultTest=__name__)

test/test_sparqlupdatestore.py

@@ -6,7 +6,7 @@
 import unittest
 import re
 
-from rdflib import ConjunctiveGraph, URIRef, Literal
+from rdflib import ConjunctiveGraph, URIRef, Literal, BNode, Graph
 from six import text_type
 from six.moves.urllib.request import urlopen
 
@@ -165,6 +165,27 @@ def testUpdateWithInitBindings(self):
             'only michel likes pizza'
         )
 
+    def testUpdateWithBlankNode(self):
+        self.graph.update(
+            "INSERT DATA { GRAPH <urn:graph> { _:blankA <urn:type> <urn:Blank> } }")
+        g = self.graph.get_context(graphuri)
+        for t in g.triples((None, None, None)):
+            self.assertTrue(isinstance(t[0], BNode))
+            self.assertEqual(t[1].n3(), "<urn:type>")
+            self.assertEqual(t[2].n3(), "<urn:Blank>")
+
+    def testUpdateWithBlankNodeSerializeAndParse(self):
+        self.graph.update(
+            "INSERT DATA { GRAPH <urn:graph> { _:blankA <urn:type> <urn:Blank> } }")
+        g = self.graph.get_context(graphuri)
+        string = g.serialize(format='ntriples').decode('utf-8')
+        raised = False
+        try:
+            Graph().parse(data=string, format="ntriples")
+        except Exception as e:
+            raised = True
+        self.assertFalse(raised, 'Exception raised when parsing: ' + string)
+
     def testMultipleUpdateWithInitBindings(self):
         self.graph.update(
             "INSERT { GRAPH <urn:graph> { ?a ?b ?c . } } WHERE { };"