[TEST] VertexRDD.apply mergeFunc

graphx/src/test/scala/org/apache/spark/graphx/VertexRDDSuite.scala

@@ -99,4 +99,21 @@ class VertexRDDSuite extends FunSuite with LocalSparkContext {
     }
   }
 
+  test("mergeFunc") {
+    // test to see if the mergeFunc is working correctly
+    withSpark { sc =>
+      // VertexRDD default constructor: Duplicate entries are removed arbitrarily.
+      // val verts = VertexRDD(sc.parallelize(List((0L, 1), (0L, 2), (1L, 3), (1L, 3), (1L, 3))))
+      // ensure constructor preserve duplicate vertex
+      // assert(verts.collect.toSet == Set((0L, 1), (0L, 2), (1L, 3), (1L, 3), (1L, 3)))
+      // won't pass
+
+      val verts = sc.parallelize(List((0L, 1), (0L, 2), (1L, 3), (1L, 3), (1L, 3)))
+      val edges = EdgeRDD.fromEdges(sc.parallelize(List.empty[Edge[Int]]))
+      val rdd = VertexRDD(verts, edges, 0, (a: Int, b: Int) => a + b)
+      // test merge function
+      assert(rdd.collect.toSet == Set((0L, 3), (1L, 9)))
+    }
+  }
+
 }