test for #607

1 files changed, 59 insertions, 0 deletions

diff --git a/test/test_issue607.py b/test/test_issue607.py
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--- /dev/null
+++ b/test/test_issue607.py
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+# test for https://github.com/RDFLib/rdflib/issues/607
+
+from rdflib import Graph, URIRef, Literal, Namespace
+from rdflib.namespace import FOAF, RDF
+
+X = Namespace("http://example.org/")
+
+sample_data = '''
+@prefix x: <http://example.org/> .
+
+x:a x:p x:b .
+x:b x:p x:c .
+x:x x:p x:y .
+'''
+
+g = Graph().parse(data=sample_data, format='n3')
+assert len(g) == 3
+
+
+# find 2 hop chain (this works)
+q = '''
+select ?a ?b ?c where {
+  ?a x:p ?b .
+  ?b x:p ?c .
+}
+'''
+expected = [(X.a, X.b, X.c)]
+res = sorted(g.query(q))
+assert res == expected, '\nexpected: %s\ngot     : %s' % (expected, res)
+
+
+# find 2 hop chain with subquery (doesn't work)
+q = '''
+select ?a ?b ?c where {
+  ?a x:p ?b .
+  {
+    select ?b ?c where {
+      ?b x:p ?c .
+    }
+  }
+}
+'''
+res = sorted(g.query(q))
+assert res == expected, '\nexpected: %s\ngot     : %s' % (expected, res)
+
+
+# find 2 hop chain with subquery, exec subquery first (works)
+q = '''
+select ?a ?b ?c where {
+  {
+    select ?b ?c where {
+      ?b x:p ?c .
+    }
+  }
+  ?a x:p ?b .
+}
+'''
+res = sorted(g.query(q))
+assert res == expected, '\nexpected: %s\ngot     : %s' % (expected, res)