Symmetrize edgelist when creating a CSR graph

cpp/src/c_api/graph_sg.cpp

@@ -761,7 +761,7 @@ cugraph_error_code_t cugraph_graph_create_sg_from_csr(
                                      p_edge_ids,
                                      p_edge_type_ids,
                                      renumber,
-                                     FALSE,  // symmetrize
+                                     symmetrize,
                                      do_expensive_check);
 
   try {

python/cugraph/cugraph/tests/structure/test_graph.py

@@ -26,6 +26,7 @@
 from cudf.testing import assert_series_equal
 from cudf.testing.testing import assert_frame_equal
 from cugraph.structure.symmetrize import symmetrize
+from cugraph.datasets import karate_asymmetric
 
 # MG
 import dask_cudf
@@ -204,6 +205,37 @@ def test_add_adj_list_to_edge_list(graph_file):
     compare_series(destinations_cu, destinations_exp)
 
 
+@pytest.mark.sg
+def test_create_undirected_graph_from_asymmetric_adj_list():
+    # karate_asymmetric.get_path()
+    Mnx = utils.read_csv_for_nx(karate_asymmetric.get_path())
+    N = max(max(Mnx["0"]), max(Mnx["1"])) + 1
+    Mcsr = scipy.sparse.csr_matrix((Mnx.weight, (Mnx["0"], Mnx["1"])), shape=(N, N))
+
+    offsets = cudf.Series(Mcsr.indptr)
+    indices = cudf.Series(Mcsr.indices)
+
+    G = cugraph.Graph(directed=False)
+
+    with pytest.raises(Exception):
+        # Ifan undirected graph is created with 'symmetrize' set to False, the
+        # edgelist provided by the user must be symmetric.
+        G.from_cudf_adjlist(offsets, indices, None, symmetrize=False)
+
+    G = cugraph.Graph(directed=False)
+    G.from_cudf_adjlist(offsets, indices, None, symmetrize=True)
+
+    # FIXME: Since we have no mechanism to access the symmetrized edgelist
+    # from the graph_view_t, assert that the edgelist size is unchanged. Once
+    # exposing 'decompress_to_edgelist', ensure that
+    # G.number_of_edges() == 2 * karate_asymmetric.get_edgelist()?
+    assert G.number_of_edges() == len(karate_asymmetric.get_edgelist())
+
+    # FIXME: Once 'decompress_to_edgelist' is exposed to the
+    # python API, ensure that the derived edgelist is symmetric
+    # if symmetrize = True.
+
+
 # Test
 @pytest.mark.sg
 @pytest.mark.parametrize("graph_file", utils.DATASETS)