def test_add_after_c_in_abc(self):
pl = PositionalList()
a = pl.add_last('a')
b = pl.add_last('b')
c = pl.add_last('c')
forty_two = pl.add_after(c, 42)
actual_after_forty_two = pl.after(forty_two)
self.assertIsNone(actual_after_forty_two)
def test_add_after_b_in_abc(self):
pl = PositionalList()
a = pl.add_last('a')
b = pl.add_last('b')
c = pl.add_last('c')
forty_two = pl.add_after(b, 42)
expected_after_forty_two = c
actual_after_forty_two = pl.after(forty_two)
self.assertEqual(expected_after_forty_two, actual_after_forty_two)
def test_add_after_a_in_abc(self):
pl = PositionalList()
a = pl.add_last('a')
b = pl.add_last('b')
c = pl.add_last('c')
forty_one = pl.add_after(a, 41)
forty_two = pl.add_after(forty_one, 42)
expected_after_forty_one = forty_two
actual_after_forty_one = pl.after(forty_one)
self.assertEqual(expected_after_forty_one, actual_after_forty_one)