def test_get_in_neighbors_unknown_key(self):
g = Graph()
g.add_node("new")
g.add_node("node")
g.add_node("test")
g.add_edge("new", "node")
g.add_edge("node", "test", 45)
with self.assertRaises(IndexError) as context:
g.get_in_neighbors("blip")
self.assertTrue(context.exception)
def test_get_in_neighbors(self):
g = Graph()
g.add_node("new")
g.add_node("node")
g.add_node("test")
g.add_edge("new", "node")
g.add_edge("node", "test", 45)
neighbors = g.get_in_neighbors("node")
self.assertEqual(neighbors, ["new"])
def test_get_in_neighbors_empty_graph(self):
g = Graph()
with self.assertRaises(IndexError) as context:
g.get_in_neighbors("test")
self.assertTrue(context.exception)