def test_non_consecutive_adding(self):
"""Test adding vertices non-consecutively."""
# Create [].
a_graph = DirectedGraph()
# Add 1 to [], which becomes [set(), set()].
# Here 0 is added implicitly.
a_graph.add(1)
self.assertEqual(a_graph.n_vertices(), 2)
self.assertEqual(a_graph.connected(0, 0), True)
self.assertEqual(a_graph.connected(0, 1), False)
self.assertEqual(a_graph.connected(1, 1), True)
def test_consecutive_adding(self):
"""Test adding vertices consecutively."""
# Create [].
a_graph = DirectedGraph()
# Add 0 to [], which becomes [set()].
a_graph.add(0)
self.assertEqual(a_graph.n_vertices(), 1)
self.assertEqual(a_graph.connected(0, 0), True)
self.assertEqual(a_graph.connected(0, 1), False)
self.assertEqual(a_graph.connected(1, 1), False)
# Add 0 to [set()], nothing changes.
a_graph.add(0)
self.assertEqual(a_graph.n_vertices(), 1)
self.assertEqual(a_graph.connected(0, 0), True)
self.assertEqual(a_graph.connected(0, 1), False)
self.assertEqual(a_graph.connected(1, 1), False)
# Add 1 to [set()], which becomes [set(), set()].
a_graph.add(1)
self.assertEqual(a_graph.n_vertices(), 2)
self.assertEqual(a_graph.connected(0, 0), True)
self.assertEqual(a_graph.connected(0, 1), False)
self.assertEqual(a_graph.connected(1, 1), True)
