def test_disordered(): assert find_target(disordered_list, 0) is 6
def test_all_equals(): assert find_target([4] * 100, 4) is 0
def test_many_missing(): assert find_target(ordered_list, 0) is None
def test_many(): assert find_target(ordered_list, 2) is 2 assert find_target(ordered_list, -1) is 1
def test_single_missing(): assert find_target([1], 2) is None
def test_single(): assert find_target([1], 1) is 0 assert find_target([None], None) is 0
def test_empty(): assert find_target([], 1) is None