old_contents: #!/usr/bin/env python
  from nose.tools import *
  import networkx as nx
  
  class TestBFS:
  
      def setUp(self):
          # simple graph
          G=nx.Graph()
          G.add_edges_from([(0,1),(1,2),(1,3),(2,4),(3,4)])
          self.G=G
  
      def test_successor(self):
          assert_equal(nx.bfs_successors(self.G,source=0),
                       {0: [1], 1: [2,3], 2:[4]})
  
      def test_predecessor(self):
          assert_equal(nx.bfs_predecessors(self.G,source=0),
                       {1: 0, 2: 1, 3: 1, 4: 2})
  
      def test_bfs_tree(self):
          T=nx.bfs_tree(self.G,source=0)
          assert_equal(sorted(T.nodes()),sorted(self.G.nodes()))
          assert_equal(sorted(T.edges()),[(0, 1), (1, 2), (1, 3), (2, 4)])
  
      def test_bfs_edges(self):
          edges=nx.bfs_edges(self.G,source=0)
          assert_equal(list(edges),[(0, 1), (1, 2), (1, 3), (2, 4)])
  
      def test_bfs_tree_isolates(self):
          G = nx.Graph()
          G.add_node(1)
          G.add_node(2)
          T=nx.bfs_tree(G,source=1)
          assert_equal(sorted(T.nodes()),[1])
          assert_equal(sorted(T.edges()),[])
  
new_contents: #!/usr/bin/env python
  from nose.tools import *
  import networkx as nx
  
  class TestBFS:
  
      def setUp(self):
          # simple graph
          G=nx.Graph()
          G.add_edges_from([(0,1),(1,2),(1,3),(2,4),(3,4)])
          self.G=G
  
      def test_successor(self):
          assert_equal(nx.bfs_successors(self.G,source=0),
                       {0: [1], 1: [2,3], 2:[4]})
  
      def test_predecessor(self):
          assert_equal(nx.bfs_predecessors(self.G,source=0),
                       {1: 0, 2: 1, 3: 1, 4: 2})
  
      def test_bfs_tree(self):
          T=nx.bfs_tree(self.G,source=0)
          assert_equal(sorted(T.nodes()),sorted(self.G.nodes()))
          assert_equal(sorted(T.edges()),[(0, 1), (1, 2), (1, 3), (2, 4)])
  
      def test_bfs_edges(self):
          edges=nx.bfs_edges(self.G,source=0)
          assert_equal(list(edges),[(0, 1), (1, 2), (1, 3), (2, 4)])
  
      def test_bfs_edges_reverse(self):
          D = nx.DiGraph()
          D.add_edges_from([(0,1),(1,2),(1,3),(2,4),(3,4)])
          edges = nx.bfs_edges(D, source=4, reverse=True)
          assert_equal(list(edges), [(4, 2), (4, 3), (2, 1), (1, 0)])
  
      def test_bfs_tree_isolates(self):
          G = nx.Graph()
          G.add_node(1)
          G.add_node(2)
          T=nx.bfs_tree(G,source=1)
          assert_equal(sorted(T.nodes()),[1])
          assert_equal(sorted(T.edges()),[])
  
subject: Add bfs test for directed graph in reverse direction