Merge pull request #209 from dotnetrdf/feature/issue-207

Fixed GetUriNode to return nodes that are used as predicate in the graph
dotnetrdf · Oct 8, 2018 · 858007e · 858007e
2 parents 50750c7 + ee4bbc4
commit 858007e
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Showing 2 changed files with 25 additions and 9 deletions.
diff --git a/Libraries/dotNetRDF/Core/Graph.cs b/Libraries/dotNetRDF/Core/Graph.cs
@@ -219,17 +219,14 @@ public override IBlankNode GetBlankNode(String nodeId)
 
         private T GetNode<T>(T node) where T: INode
         {
-            var withSubject = Triples.WithSubject(node);
-            var withObject = Triples.WithObject(node);
+            var ret = (T) Triples.WithSubject(node).FirstOrDefault()?.Subject;
+            if (ret != null) return ret;
 
-            var firstWithSubject = withSubject.FirstOrDefault();
+            ret = (T) Triples.WithObject(node).FirstOrDefault()?.Object;
+            if (ret != null) return ret;
 
-            if (firstWithSubject != null)
-            {
-                return (T)firstWithSubject.Subject;
-            }
-
-            return (T)withObject.FirstOrDefault()?.Object;
+            ret = (T) Triples.WithPredicate(node).FirstOrDefault()?.Predicate;
+            return ret;
         }
 
         #endregion

diff --git a/Testing/unittest/Core/AbstractGraphTests.cs b/Testing/unittest/Core/AbstractGraphTests.cs
@@ -142,6 +142,25 @@ public void GetUriNode_ShouldReturnIfUsedAsSubject()
             Assert.Same(node, uriNode);
         }
 
+        [Fact]
+        public void GetUriNode_ShouldReturnIfUsedAsPredicate()
+        {
+            // given
+            var graph = GetInstance();
+            var uri = new Uri("http://example.com/pred");
+            var node = graph.CreateUriNode(uri);
+            graph.Assert(
+                graph.CreateBlankNode(),
+                node,
+                graph.CreateBlankNode());
+
+            // subj
+            var uriNode = graph.GetUriNode(uri);
+
+            // then
+            Assert.Same(node, uriNode);
+        }
+
         [Fact]
         public void GetUriNode_ShouldReturnNullWhenNotFound()
         {