def test_add_node(self):
gr = Graph()
gr.add_node("Hello")
self.assertIn("Hello", gr)
def test_has_cycle(self):
gr = Graph()
gr.add_node("foo", "bar")
gr.add_edge("foo", "bar")
gr.add_edge("bar", "foo")
self.assertTrue(gr.has_cycle())
def test_no_cycle(self):
gr = Graph()
gr.add_node("foo", "bar")
gr.add_edge("foo", "bar")
self.assertFalse(gr.has_cycle())
def test_add_edges(self):
gr = Graph()
with self.assertRaises(KeyError):
gr.add_edge("Hello", "Goodbye")
def test_add_edge(self):
gr = Graph()
gr.add_node("foo", "bar")
gr.add_edge("foo", "bar")
self.assertIn("bar", gr["foo"])
def test_add_nodes(self):
gr = Graph()
gr.add_node("Hello", "Goodbye")
self.assertIn("Hello", gr)
self.assertIn("Goodbye", gr)
