diff --git a/pyproject.toml b/pyproject.toml
index 84f45a3..17cfb62 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,6 @@ warn_unused_configs = true
 line-length = 120
 extend-exclude = '''
 (
-    tests
-    | docs
+    docs
 )
 '''
diff --git a/tests/test_number_functions.py b/tests/test_number_functions.py
index 19b3796..f3e9021 100644
--- a/tests/test_number_functions.py
+++ b/tests/test_number_functions.py
@@ -3,41 +3,50 @@
 from my_package.number_functions import add_one, subtract_one, sum_array
 
 
-@pytest.mark.parametrize("test_input,expected", [
-    (1, 2),
-    (0, 1),
-    (-4, -3),
-    (2.5, 3.5),
-])
+@pytest.mark.parametrize(
+    ("test_input", "expected"),
+    (
+        (1, 2),
+        (0, 1),
+        (-4, -3),
+        (2.5, 3.5),
+    ),
+)
 def test_add_one(test_input, expected):
     assert add_one(test_input) == expected
 
 
-@pytest.mark.parametrize("test_input,expected", [
-    (1, 0),
-    (0, -1),
-    (-4, -5),
-    (2.5, 1.5),
-])
+@pytest.mark.parametrize(
+    ("test_input", "expected"),
+    (
+        (1, 0),
+        (0, -1),
+        (-4, -5),
+        (2.5, 1.5),
+    ),
+)
 def test_subtract_one(test_input, expected):
     assert subtract_one(test_input) == expected
 
 
 def test_add_one_typeerror():
     with pytest.raises(TypeError):
-        add_one('some string')
+        add_one("some string")
 
 
 def test_subtract_one_typeerror():
     with pytest.raises(TypeError):
-        subtract_one('another string')
-
-
-@pytest.mark.parametrize("test_input,expected", [
-    (np.array([1, 2]), 3),
-    (np.array([]), 0),
-    (np.ones(3), 3),
-    (np.zeros(5), 0),
-])
+        subtract_one("another string")
+
+
+@pytest.mark.parametrize(
+    ("test_input", "expected"),
+    (
+        (np.array([1, 2]), 3),
+        (np.array([]), 0),
+        (np.ones(3), 3),
+        (np.zeros(5), 0),
+    ),
+)
 def test_sum_array(test_input, expected):
     assert sum_array(test_input) == expected
diff --git a/tests/test_string_functions.py b/tests/test_string_functions.py
index 69ae6c2..8cb7ba8 100644
--- a/tests/test_string_functions.py
+++ b/tests/test_string_functions.py
@@ -2,29 +2,35 @@
 from my_package.string_functions import reverse_string, add_exclamation_mark
 
 
-@pytest.mark.parametrize("test_input,expected", [
-    ('abc', 'cba'),
-    ('aaa', 'aaa'),
-    ('', ''),
-])
+@pytest.mark.parametrize(
+    ("test_input", "expected"),
+    (
+        ("abc", "cba"),
+        ("aaa", "aaa"),
+        ("", ""),
+    ),
+)
 def test_reverse_string(test_input, expected):
     assert reverse_string(test_input) == expected
 
 
-@pytest.mark.parametrize("test_input,expected", [
-    ('Hello world', 'Hello world!'),
-    ('abc', 'abc!'),
-    ('', '!'),
-])
+@pytest.mark.parametrize(
+    ("test_input", "expected"),
+    (
+        ("Hello world", "Hello world!"),
+        ("abc", "abc!"),
+        ("", "!"),
+    ),
+)
 def test_add_exclamation_mark(test_input, expected):
     assert add_exclamation_mark(test_input) == expected
 
 
-# def test_reverse_string_raises_typeerror():
-#     with pytest.raises(TypeError):
-#         reverse_string(3)
+def test_reverse_string_raises_type_error():
+    with pytest.raises(TypeError):
+        reverse_string(3)
 
 
-def test_add_exclamation_mark_raises_typeerror():
+def test_add_exclamation_mark_raises_type_error():
     with pytest.raises(TypeError):
         add_exclamation_mark(1)