def test_is_full_returns_correct_boolean_value(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz', 'spam', 'eggs']
d._data[2:7] = elements
d._size = 5
d._front = 2
self.assertFalse(d.is_full())
d = ArrayDeque(maxlen=5)
elements = ['foo', 'bar', 'baz', 'spam', 'eggs']
d._data = elements
d._size = 5
self.assertTrue(d.is_full())
def test_remove_shifts_elements_from_shorter_end_of_deque(self):
d = ArrayDeque()
elements = ['1st', '2nd', '3rd', '4th', '5th', '6th', '7th']
d._data[0:7] = elements
d._front = 0
d._size = 7
# ['1st', '2nd', '3rd', '4th', '5th', '6th', '7th']
# 0 1 2 3 4 5 6
# for i in range self._size -> i in range(7):
# current = 1
# 1 < self._size // 2 -> 1 < 3
#
d.remove('2nd')
self.assertEqual(d._data[1:7],
['1st', '3rd', '4th', '5th', '6th', '7th'])
self.assertEqual(d._front,
1) # front moved as elements left of center shifted
d.remove('6th')
self.assertEqual(d._data[1:6], ['1st', '3rd', '4th', '5th', '7th'])
self.assertEqual(d._front, 1) # the front has not moved
def test_remove_raises_ValueError_when_value_not_in_deque(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz', 'bar']
d._data[2:6] = elements
d._size = 4
d._front = 2
self.assertRaises(ValueError, d.remove, 'spam')
def test_constructor_with_maxlen_less_than_default_capacity_shrinks_size(
self):
expected_result = 5
d = ArrayDeque(maxlen=expected_result) # less than DEFAULT_CAPACITY
result = len(d._data)
self.assertEqual(result, expected_result)
def test_add_last_doubles_deque_size_if_capacity_reached(self):
expected_result = ArrayDeque.DEFAULT_CAPACITY * 2
d = ArrayDeque()
for e in range(ArrayDeque.DEFAULT_CAPACITY + 1):
d.add_last(e)
result = len(d._data)
self.assertEqual(result, expected_result)
def test_setitem_raises_IndexError_with_integer_index_out_of_range(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz']
d._data[2:5] = elements
d._front = 2
d._size = 3
self.assertRaises(IndexError, d.__setitem__, 3, 'nope')
self.assertRaises(IndexError, d.__setitem__, -4, 'nope')
def test_getitem_raises_NotImplementedError_with_slice_object_parameter(
self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz', 'spam', 'eggs']
d._data[2:7] = elements
d._front = 2
d._size = 5
self.assertRaises(NotImplementedError, d.__getitem__, slice(0, 2))
def test_count_returns_correct_number_of_matches_for_value_in_deque(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz', 'bar']
d._data[-2:2] = elements
d._size = 4
d._front = 8
self.assertEqual(2, d.count('bar'))
self.assertEqual(1, d.count('foo'))
self.assertEqual(0, d.count('spam'))
def test_rotate_shifts_deque_to_left_with_negative_steps_integer(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz']
expected_elements = ['baz', 'foo', 'bar']
d._data[0:3] = elements
d._front = 0
d._size = 3
d.rotate(-2)
self.assertEqual(d._data[2:5], expected_elements)
def test_is_empty_returns_correct_boolean_value(self):
d = ArrayDeque()
self.assertTrue(d.is_empty())
elements = ['foo', 'bar', 'baz']
d._data[2:5] = elements
d._size = 3
d._front = 2
self.assertFalse(d.is_empty())
def test_getitem_returns_correct_element_with_negative_integer_index(self):
d = ArrayDeque()
expected_result = 'foo'
elements = [expected_result, 'bar', 'baz']
d._data[2:5] = elements
d._front = 2
d._size = 3
result = d[-3]
self.assertEqual(result, expected_result)
def test_resize_preserves_order_of_enqueued_elements(self):
elements = ['foo', 'bar', 'baz']
expected_sequence = [None] * 20
expected_sequence[0:3] = elements
d = ArrayDeque()
d._data[2:5] = elements
d._size = 3
d._front = 2
d._resize(20)
self.assertSequenceEqual(d._data, expected_sequence)
def test_remove_deletes_first_instance_of_value_in_deque(self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz', 'bar']
d._data[2:6] = elements
d._size = 4
d._front = 2
d.remove('bar')
self.assertEqual(d._size, 3)
self.assertIn('bar', d._data)
self.assertEqual(d._data[3:6], ['foo', 'baz', 'bar'])
def test_last_returns_last_element_without_removing_it(self):
elements = ['foo', 'bar', 'baz']
expected_result = 'baz'
d = ArrayDeque()
d._data[2:5] = elements
d._size = 3
d._front = 2
result = d.last()
self.assertEqual(result, expected_result)
self.assertIn(expected_result, d._data)
def test_add_last_adds_an_element_to_the_back_of_deque(self):
elements = ['foo', 'bar']
expected_result = 'baz'
d = ArrayDeque()
d._data[2:4] = elements
d._size = 2
d._front = 2
d.add_last(expected_result)
result = d._data[4]
self.assertEqual(result, expected_result)
def test_delete_last_returns_and_removes_last_element_from_deque(self):
elements = ['foo', 'bar']
expected_result = 'bar'
d = ArrayDeque()
d._data[2:4] = elements
d._size = 2
d._front = 2
result = d.delete_last()
self.assertEqual(d._size, 1)
self.assertEqual(result, expected_result)
self.assertNotIn('bar', d._data)
def test_setitem_replaces_correct_element_with_positive_integer_index(
self):
d = ArrayDeque()
expected_result = 'spam'
elements = ['foo', 'bar', 'baz']
d._data[2:5] = elements
d._front = 2
d._size = 3
d[0] = expected_result
result = d[0]
self.assertEqual(result, expected_result)
def test_clear_resets_deque_resizes_data_to_default_capacity_without_maxlen(
self):
d = ArrayDeque()
elements = ['foo', 'bar', 'baz']
d._data[2:5] = elements
d._front = 2
d._size = 3
d.clear()
self.assertEqual(d._size, 0)
self.assertEqual(d._front, 0)
self.assertEqual(len(d._data), d.DEFAULT_CAPACITY)
def test_clear_resets_deque_resizes_data_to_maxlen_with_maxlen_provided(
self):
d = ArrayDeque(maxlen=5)
elements = ['foo', 'bar', 'baz']
d._data[2:5] = elements
d._front = 2
d._size = 3
d.clear()
self.assertEqual(d._size, 0)
self.assertEqual(d._front, 0)
self.assertEqual(len(d._data), d._maxlen)
def test_len_returns_size_of_deque(self):
d = ArrayDeque()
expected_result = 0
result = len(d)
self.assertEqual(result, expected_result)
d._data = ['foo']
d._size = 1
expected_result = 1
result = len(d)
self.assertEqual(result, expected_result)
def test_delete_last_raises_Empty_exception_if_deque_is_empty(self):
d = ArrayDeque()
self.assertRaises(Empty, d.delete_last)
def test_resize_increases_capacity(self):
d = ArrayDeque()
d._resize(50)
self.assertEqual(len(d._data), 50)