1 files changed, 12 insertions, 11 deletions
diff --git a/tests/test_natsort_key.py b/tests/test_natsort_key.py
index 6b56bb1..8034a8c 100644
--- a/tests/test_natsort_key.py
+++ b/tests/test_natsort_key.py
@@ -1,42 +1,43 @@
 # -*- coding: utf-8 -*-
 """These test the utils.py functions."""
+from typing import Any as Any_t, List, NoReturn, Tuple, Union
 
 from hypothesis import given
 from hypothesis.strategies import binary, floats, integers, lists, text
 from natsort.utils import natsort_key
 
 
-def str_func(x):
+def str_func(x: Any_t) -> Tuple[str]:
     if isinstance(x, str):
-        return x
+        return (x,)
     else:
         raise TypeError("Not a str!")
 
 
-def fail(_):
+def fail(_: Any_t) -> NoReturn:
     raise AssertionError("This should never be reached!")
 
 
 @given(floats(allow_nan=False) | integers())
-def test_natsort_key_with_numeric_input_takes_number_path(x):
-    assert natsort_key(x, None, str_func, fail, lambda y: y) is x
+def test_natsort_key_with_numeric_input_takes_number_path(x: Union[float, int]) -> None:
+    assert natsort_key(x, None, str_func, fail, lambda y: ("", y)) is x
 
 
 @given(binary().filter(bool))
-def test_natsort_key_with_bytes_input_takes_bytes_path(x):
-    assert natsort_key(x, None, str_func, lambda y: y, fail) is x
+def test_natsort_key_with_bytes_input_takes_bytes_path(x: bytes) -> None:
+    assert natsort_key(x, None, str_func, lambda y: (y,), fail) is x
 
 
 @given(text())
-def test_natsort_key_with_text_input_takes_string_path(x):
+def test_natsort_key_with_text_input_takes_string_path(x: str) -> None:
     assert natsort_key(x, None, str_func, fail, fail) is x
 
 
 @given(lists(elements=text(), min_size=1, max_size=10))
-def test_natsort_key_with_nested_input_takes_nested_path(x):
+def test_natsort_key_with_nested_input_takes_nested_path(x: List[str]) -> None:
     assert natsort_key(x, None, str_func, fail, fail) == tuple(x)
 
 
 @given(text())
-def test_natsort_key_with_key_argument_applies_key_before_processing(x):
-    assert natsort_key(x, len, str_func, fail, lambda y: y) == len(x)
+def test_natsort_key_with_key_argument_applies_key_before_processing(x: str) -> None:
+    assert natsort_key(x, len, str_func, fail, lambda y: ("", y)) == len(x)