def test_no_path(self):
g = Graph()
a = g.add_node(Node())
b = g.add_node(Node())
# no edges between them
path = g.get_shortest_path(a, b)
self.assertEqual(path, []) # FIXME: shouldn't this be None?
def add_long_path(g, length):
"""
Construct a path of the form:
first -> n0 -> n1 -> .... -> last
where there are "length" edges
"""
first = g.add_node(Node())
last = first
cur = first
for i in range(length):
last = g.add_node(Node())
g.add_edge(cur, last)
cur = last
return first, last
