def test_considers_lo_as_minimum_value(self):
self.assertEqual(lower_bound([], 'a', lo=1), 1)
self.assertEqual(lower_bound([], 'a', lo=2), 2)
self.assertEqual(lower_bound([], 'a', lo=3), 3)
self.assertEqual(lower_bound(['aa', 'ab'], 'ac'), 2)
self.assertEqual(lower_bound(['aa', 'ab'], 'ac', lo=1), 2)
self.assertEqual(lower_bound(['aa', 'ab'], 'ac', lo=2), 2)
self.assertEqual(lower_bound(['aa', 'ab'], 'ac', lo=3), 3)
self.assertEqual(lower_bound(['aa', 'ab'], 'ac', lo=4), 4)
def test_considers_hi_as_maximum_value(self):
self.assertEqual(lower_bound(['aa', 'ab'], 'ac', hi=1), 1)
self.assertEqual(
lower_bound(['alpha', 'beta', 'charlie'], 'blue', hi=1), 1)
self.assertEqual(
lower_bound(['blue', 'charlie', 'definitive'], 'zulu'), 3)
self.assertEqual(
lower_bound(['blue', 'charlie', 'definitive'], 'zulu', hi=2), 2)
self.assertEqual(
lower_bound(['blue', 'charlie', 'definitive'], 'zulu', hi=1), 1)
self.assertEqual(
lower_bound(['blue', 'charlie', 'definitive'], 'zulu', hi=0), 0)
def test_returns_0_when_list_is_empty(self):
self.assertEqual(lower_bound([], 'a'), 0)
self.assertEqual(lower_bound([], 'b'), 0)
self.assertEqual(lower_bound([], '1'), 0)
self.assertEqual(lower_bound([], 'alpha'), 0)
def test_raises_if_hi_is_bigger_than_length_of_array(self):
with self.assertRaises(ValueError):
lower_bound([], 'a', hi=1)
with self.assertRaises(ValueError):
lower_bound(['a'], 'b', hi=2)
def test_raises_if_lo_is_less_than_zero(self):
with self.assertRaises(ValueError):
lower_bound([], 'a', lo=-1)
with self.assertRaises(ValueError):
lower_bound([], 'a', lo=-2)
def test_returns_list_size_when_item_is_higher_than_all(self):
self.assertEqual(lower_bound(['b'], 'c'), 1)
self.assertEqual(
lower_bound(['blue', 'charlie', 'definitive'], 'zulu'), 3)
def test_returns_first_index_when_several_items_are_equal(self):
self.assertEqual(lower_bound(['a'], 'a'), 0)
self.assertEqual(lower_bound(['a', 'b'], 'b'), 1)
self.assertEqual(lower_bound(['a', 'c', 'd', 'd'], 'd'), 2)
def test_considers_words_ordered_alphabetically(self):
self.assertEqual(lower_bound(['aa', 'ab'], 'ac'), 2)
self.assertEqual(lower_bound(['alpha', 'charlie'], 'blue'), 1)
def test_identifies_index_in_the_middle_of_list(self):
self.assertEqual(lower_bound(['alpha', 'beta', 'charlie'], 'blue'),
2) # blue > alpha and blue > beta