def test_construct(source, expected_list):
"""
GIVEN source for construction and expected list
WHEN the Heap is constructed with the source
THEN the underlying list is set to the expected list.
"""
test_heap = heap.Heap(source)
assert test_heap._list == expected_list
def test_extract_max_empty():
"""
GIVEN empty heap
WHEN extract_max is called
THEN IndexError is raised.
"""
test_heap = heap.Heap()
with pytest.raises(IndexError):
test_heap.extract_max()
def test_size(source, expected_size):
"""
GIVEN source for heap and expected size
WHEN heap is constructed with the source and len is called
THEN the expected size is returned.
"""
test_heap = heap.Heap(source)
size = len(test_heap)
assert size == expected_size
def test_is_empty(source, expected_result):
"""
GIVEN source for heap and expected result
WHEN heap is constructed with the source and is_empty is called
THEN the expected result is returned.
"""
test_heap = heap.Heap(source)
result = test_heap.is_empty()
assert result == expected_result
def test_insert(source, value, expected):
"""
GIVEN source, value to insert and expected final list
WHEN the heap is constructed with the source and insert is called with the value
THEN the underlying list contains the expected elements in the expected order.
"""
test_heap = heap.Heap(source)
test_heap.insert(value)
assert test_heap._list == expected
def test_sorted(source, expected):
"""
GIVEN source of elements and expected sorted elements
WHEN the heap is constructed with the source and sorted is called
THEN an iterator is returned with the elements in the expected order.
"""
test_heap = heap.Heap(source)
returned = list(test_heap.sorted())
assert returned == expected
def test_heapify(initial, expected):
"""
GIVEN initial elements
WHEN _heapify is called
THEN the elements are in the expected order.
"""
test_heap = heap.Heap()
test_heap._list = initial
test_heap._heapify()
assert test_heap._list == expected
def test_sift_down(initial, start, end, expected):
"""
GIVEN initial elements for the list of a heap that satisfy the heap property
except for possibly the start and the start and the end
WHEN _sift down is called with the start and the end
THEN the final list is equal to the expected list.
"""
test_heap = heap.Heap()
test_heap._list = initial
test_heap._sift_down(start, end)
assert test_heap._list == expected
def test_extract_max(source, expected_value, expected_list):
"""
GIVEN source for heap, expected value and expected list
WHEN a heap is constructed with the source and extract_max is called
THEN the expected value is returned and the underlying list of the heap is the
expected list.
"""
test_heap = heap.Heap(source)
value = test_heap.extract_max()
assert value == expected_value
assert test_heap._list == expected_list
def test_sort_random(random_list): # pylint: disable=redefined-outer-name
"""
GIVEN random list
WHEN a heap is constructed with the list as the source and sorted is called
THEN a sorted list of elements is returned.
"""
test_heap = heap.Heap(random_list)
returned = test_heap.sorted()
previous = next(returned)
element_count = 1
for current in returned:
assert current <= previous
element_count += 1
assert element_count == len(random_list)
