def test_insertion_sort_nearly_sorted():
arr = [2, 3, 5, 7, 13, 11]
expected = [2, 3, 5, 7, 11, 13]
actual = insertion_sort(arr)
assert actual == expected
def test_insertion_sort_simple():
arr = [8, 4, 23, 42, 16, 15]
expected = [4, 8, 15, 16, 23, 42]
actual = insertion_sort(arr)
assert actual == expected
def test_insertion_sort_reverse():
arr = [20, 18, 12, 8, 5, -2]
expected = [-2, 5, 8, 12, 18, 20]
actual = insertion_sort(arr)
assert actual == expected
def test_insertion_sort_few_unique():
arr = [5, 12, 7, 5, 5, 7]
expected = [5, 5, 5, 7, 7, 12]
actual = insertion_sort(arr)
assert actual == expected
def test_already_sorted():
array = [1, 2, 3, 4, 5]
test = insertion_sort(array)
assert test == [1, 2, 3, 4, 5]
def test_insertion_sort_empty():
array = []
test = insertion_sort(array)
assert test == []
def test_insertion_sort_single():
array = [1]
test = insertion_sort(array)
assert test == [1]
def test_insertion_sort_duplicates():
array = [1, 5, 4, 3, 2, 1]
test = insertion_sort(array)
assert test == [1, 1, 2, 3, 4, 5]
def test_insertion_sort():
array = [5, 4, 3, 2, 1]
test = insertion_sort(array)
assert test == [1, 2, 3, 4, 5]
