diff --git a/test/sanity/code-smell/mypy.json b/test/sanity/code-smell/mypy.json
index 57a6ad6c15b..c8cd6fb8f5e 100644
--- a/test/sanity/code-smell/mypy.json
+++ b/test/sanity/code-smell/mypy.json
@@ -3,11 +3,13 @@
         "lib/ansible/",
         "test/lib/ansible_test/_internal/",
         "packaging/",
+        "test/units",
         "test/lib/ansible_test/_util/target/sanity/import/"
     ],
     "extensions": [
         ".py"
     ],
     "multi_version": "controller",
+    "error_code": "ansible-test",
     "output": "path-line-column-code-message"
 }
diff --git a/test/sanity/code-smell/mypy.py b/test/sanity/code-smell/mypy.py
index fda83e8b0da..b7feffc5032 100644
--- a/test/sanity/code-smell/mypy.py
+++ b/test/sanity/code-smell/mypy.py
@@ -36,6 +36,8 @@ def main() -> None:
         MyPyContext('ansible-core', ['lib/ansible/'], controller_python_versions),
         MyPyContext('modules', ['lib/ansible/modules/', 'lib/ansible/module_utils/'], remote_only_python_versions),
         MyPyContext('packaging', ['packaging/'], controller_python_versions),
+        MyPyContext('modules', ['test/units/modules/', 'test/units/module_utils/'], remote_only_python_versions),
+        MyPyContext('ansible-core', ['test/units/'], controller_python_versions),
     )
 
     unfiltered_messages: list[SanityMessage] = []
diff --git a/test/sanity/code-smell/mypy.requirements.in b/test/sanity/code-smell/mypy.requirements.in
index 073513bdf8b..2c6dee12676 100644
--- a/test/sanity/code-smell/mypy.requirements.in
+++ b/test/sanity/code-smell/mypy.requirements.in
@@ -2,6 +2,7 @@ mypy
 cryptography  # type stubs not published separately
 jinja2  # type stubs not published separately
 packaging  # type stubs not published separately
+pytest  # type stubs not published separately
 tomli  # type stubs not published separately, required for toml inventory plugin
 types-backports
 types-paramiko
diff --git a/test/sanity/code-smell/mypy.requirements.txt b/test/sanity/code-smell/mypy.requirements.txt
index c5a3ece72cd..59a253d9f9e 100644
--- a/test/sanity/code-smell/mypy.requirements.txt
+++ b/test/sanity/code-smell/mypy.requirements.txt
@@ -1,12 +1,15 @@
 # edit "mypy.requirements.in" and generate with: hacking/update-sanity-requirements.py --test mypy
 cffi==1.17.1
 cryptography==43.0.1
+iniconfig==2.0.0
 Jinja2==3.1.4
 MarkupSafe==2.1.5
 mypy==1.11.2
 mypy-extensions==1.0.0
 packaging==24.1
+pluggy==1.5.0
 pycparser==2.22
+pytest==8.3.3
 tomli==2.0.2
 types-backports==0.1.3
 types-paramiko==3.5.0.20240928
diff --git a/test/sanity/code-smell/mypy/ansible-core.ini b/test/sanity/code-smell/mypy/ansible-core.ini
index 0d2208be2dd..83b63e52eea 100644
--- a/test/sanity/code-smell/mypy/ansible-core.ini
+++ b/test/sanity/code-smell/mypy/ansible-core.ini
@@ -11,6 +11,16 @@ strict_optional = False
 # The safe-super rule is disabled because it reports false positives on methods which return None.
 disable_error_code = attr-defined,safe-super
 
+# Some controller unit tests use ansible_collections imports, both real and test-specific.
+# The real imports are not currently visible to mypy.
+# There's little point in exposing the test-specific imports.
+[mypy-ansible_collections.*]
+ignore_missing_imports = True
+
+# Some unit tests for ansible-test use ansible_test imports, which are not currently visible to mypy.
+[mypy-ansible_test.*]
+ignore_missing_imports = True
+
 [mypy-ansible.module_utils.six.moves.*]
 ignore_missing_imports = True
 
diff --git a/test/sanity/ignore.txt b/test/sanity/ignore.txt
index 17f893aabf0..926fb4bf929 100644
--- a/test/sanity/ignore.txt
+++ b/test/sanity/ignore.txt
@@ -164,3 +164,72 @@ lib/ansible/module_utils/pycompat24.py pylint:ansible-deprecated-version
 lib/ansible/plugins/connection/__init__.py pylint:ansible-deprecated-version
 lib/ansible/plugins/filter/core.py pylint:ansible-deprecated-version
 lib/ansible/vars/manager.py pylint:ansible-deprecated-version
+test/units/module_utils/basic/test_exit_json.py mypy-3.13:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.13:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.13:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.13:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.13:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.13:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.13:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.13:assignment
+test/units/modules/mount_facts_data.py mypy-3.13:arg-type
+test/units/modules/test_apt.py mypy-3.13:name-match
+test/units/modules/test_mount_facts.py mypy-3.13:index
+test/units/playbook/test_base.py mypy-3.13:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.12:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.12:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.12:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.12:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.12:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.12:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.12:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.12:assignment
+test/units/modules/mount_facts_data.py mypy-3.12:arg-type
+test/units/modules/test_apt.py mypy-3.12:name-match
+test/units/modules/test_mount_facts.py mypy-3.12:index
+test/units/playbook/test_base.py mypy-3.12:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.11:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.11:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.11:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.11:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.11:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.11:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.11:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.11:assignment
+test/units/modules/mount_facts_data.py mypy-3.11:arg-type
+test/units/modules/test_apt.py mypy-3.11:name-match
+test/units/modules/test_mount_facts.py mypy-3.11:index
+test/units/playbook/test_base.py mypy-3.11:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.10:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.10:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.10:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.10:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.10:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.10:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.10:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.10:assignment
+test/units/modules/mount_facts_data.py mypy-3.10:arg-type
+test/units/modules/test_apt.py mypy-3.10:name-match
+test/units/modules/test_mount_facts.py mypy-3.10:index
+test/units/module_utils/basic/test_exit_json.py mypy-3.9:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.9:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.9:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.9:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.9:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.9:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.9:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.9:assignment
+test/units/modules/mount_facts_data.py mypy-3.9:arg-type
+test/units/modules/test_apt.py mypy-3.9:name-match
+test/units/modules/test_mount_facts.py mypy-3.9:index
+test/units/module_utils/basic/test_exit_json.py mypy-3.8:assignment
+test/units/module_utils/basic/test_exit_json.py mypy-3.8:misc
+test/units/module_utils/common/text/converters/test_json_encode_fallback.py mypy-3.8:abstract
+test/units/module_utils/facts/other/test_facter.py mypy-3.8:assignment
+test/units/module_utils/facts/other/test_ohai.py mypy-3.8:assignment
+test/units/module_utils/facts/system/test_lsb.py mypy-3.8:assignment
+test/units/module_utils/facts/test_collectors.py mypy-3.8:assignment
+test/units/module_utils/facts/test_facts.py mypy-3.8:assignment
+test/units/modules/mount_facts_data.py mypy-3.8:arg-type
+test/units/modules/test_apt.py mypy-3.8:name-match
+test/units/modules/test_mount_facts.py mypy-3.8:index
diff --git a/test/units/cli/test_galaxy.py b/test/units/cli/test_galaxy.py
index 5444d148d06..9d6d32bb2a5 100644
--- a/test/units/cli/test_galaxy.py
+++ b/test/units/cli/test_galaxy.py
@@ -45,7 +45,7 @@ import unittest
 from unittest.mock import patch, MagicMock
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     yield
diff --git a/test/units/cli/test_vault.py b/test/units/cli/test_vault.py
index c6f41c5b912..6305a02350a 100644
--- a/test/units/cli/test_vault.py
+++ b/test/units/cli/test_vault.py
@@ -35,7 +35,7 @@ from ansible.utils import context_objects as co
 #       mock calls
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     yield
diff --git a/test/units/galaxy/test_api.py b/test/units/galaxy/test_api.py
index 6acd165b1df..2ef1d07325f 100644
--- a/test/units/galaxy/test_api.py
+++ b/test/units/galaxy/test_api.py
@@ -29,7 +29,7 @@ from ansible.utils import context_objects as co
 from ansible.utils.display import Display
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     # Required to initialise the GalaxyAPI object
diff --git a/test/units/galaxy/test_collection.py b/test/units/galaxy/test_collection.py
index bfabd81d9ee..73e915dee65 100644
--- a/test/units/galaxy/test_collection.py
+++ b/test/units/galaxy/test_collection.py
@@ -31,7 +31,7 @@ from ansible.utils.display import Display
 from ansible.utils.hashing import secure_hash_s
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     yield
diff --git a/test/units/galaxy/test_collection_install.py b/test/units/galaxy/test_collection_install.py
index 6559535f931..dc6dbe5b6f3 100644
--- a/test/units/galaxy/test_collection_install.py
+++ b/test/units/galaxy/test_collection_install.py
@@ -53,7 +53,7 @@ def call_galaxy_cli(args):
         co.GlobalCLIArgs._Singleton__instance = orig
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     yield
@@ -992,9 +992,7 @@ def test_install_collection_with_no_dependency(collection_artifact, monkeypatch)
         (["good_signature", "good_signature"], '2', [], True),
     ]
 )
-def test_verify_file_signatures(signatures, required_successful_count, ignore_errors, expected_success):
-    # type: (List[bool], int, bool, bool) -> None
-
+def test_verify_file_signatures(signatures: list[str], required_successful_count: str, ignore_errors: list[str], expected_success: bool) -> None:
     def gpg_error_generator(results):
         for result in results:
             if isinstance(result, collection.gpg.GpgBaseError):
diff --git a/test/units/galaxy/test_role_install.py b/test/units/galaxy/test_role_install.py
index 25dff80cd63..8e77352a30f 100644
--- a/test/units/galaxy/test_role_install.py
+++ b/test/units/galaxy/test_role_install.py
@@ -28,7 +28,7 @@ def call_galaxy_cli(args):
         co.GlobalCLIArgs._Singleton__instance = orig
 
 
-@pytest.fixture(autouse='function')
+@pytest.fixture(autouse=True)
 def reset_cli_args():
     co.GlobalCLIArgs._Singleton__instance = None
     yield
diff --git a/test/units/module_utils/basic/test_argument_spec.py b/test/units/module_utils/basic/test_argument_spec.py
index 46a3e9d9f31..4fea4745053 100644
--- a/test/units/module_utils/basic/test_argument_spec.py
+++ b/test/units/module_utils/basic/test_argument_spec.py
@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import json
 import os
+import typing as t
 
 import pytest
 
@@ -69,7 +70,7 @@ VALID_SPECS = (
     ({'arg': {'type': 'int'}}, {'arg': 1, 'invalid': True, '_ansible_ignore_unknown_opts': True}, 1),
 )
 
-INVALID_SPECS = (
+INVALID_SPECS: tuple[tuple[dict[str, t.Any], dict[str, t.Any], str], ...] = (
     # Type is int; unable to convert this string
     ({'arg': {'type': 'int'}}, {'arg': "wolf"}, f"is of type {type('wolf')} and we were unable to convert to int:"),
     # Type is list elements is int; unable to convert this string
@@ -495,7 +496,7 @@ class TestComplexOptions:
     )
 
     # (Parameters, failure message)
-    FAILING_PARAMS_LIST = (
+    FAILING_PARAMS_LIST: tuple[tuple[dict[str, list[dict[str, t.Any]]], str], ...] = (
         # Missing required option
         ({'foobar': [{}]}, 'missing required arguments: foo found in foobar'),
         # Invalid option
@@ -518,7 +519,7 @@ class TestComplexOptions:
     )
 
     # (Parameters, failure message)
-    FAILING_PARAMS_DICT = (
+    FAILING_PARAMS_DICT: tuple[tuple[dict[str, dict[str, t.Any]], str], ...] = (
         # Missing required option
         ({'foobar': {}}, 'missing required arguments: foo found in foobar'),
         # Invalid option
diff --git a/test/units/module_utils/basic/test_exit_json.py b/test/units/module_utils/basic/test_exit_json.py
index 795e9c1eb6e..0f6844b24a1 100644
--- a/test/units/module_utils/basic/test_exit_json.py
+++ b/test/units/module_utils/basic/test_exit_json.py
@@ -7,12 +7,13 @@ from __future__ import annotations
 import json
 import sys
 import datetime
+import typing as t
 
 import pytest
 
 from ansible.module_utils.common import warnings
 
-EMPTY_INVOCATION = {u'module_args': {}}
+EMPTY_INVOCATION: dict[str, dict[str, t.Any]] = {u'module_args': {}}
 DATETIME = datetime.datetime.strptime('2020-07-13 12:50:00', '%Y-%m-%d %H:%M:%S')
 
 
@@ -20,7 +21,7 @@ class TestAnsibleModuleExitJson:
     """
     Test that various means of calling exitJson and FailJson return the messages they've been given
     """
-    DATA = (
+    DATA: tuple[tuple[dict[str, t.Any]], ...] = (
         ({}, {'invocation': EMPTY_INVOCATION}),
         ({'msg': 'message'}, {'msg': 'message', 'invocation': EMPTY_INVOCATION}),
         ({'msg': 'success', 'changed': True},
diff --git a/test/units/module_utils/basic/test_no_log.py b/test/units/module_utils/basic/test_no_log.py
index c8c3ecea688..409d919164f 100644
--- a/test/units/module_utils/basic/test_no_log.py
+++ b/test/units/module_utils/basic/test_no_log.py
@@ -5,6 +5,7 @@
 
 from __future__ import annotations
 
+import typing as t
 import unittest
 
 from ansible.module_utils.basic import remove_values
@@ -12,7 +13,7 @@ from ansible.module_utils.common.parameters import _return_datastructure_name
 
 
 class TestReturnValues(unittest.TestCase):
-    dataset = (
+    dataset: tuple[tuple[t.Any, frozenset[str]], ...] = (
         ('string', frozenset(['string'])),
         ('', frozenset()),
         (1, frozenset(['1'])),
diff --git a/test/units/module_utils/basic/test_safe_eval.py b/test/units/module_utils/basic/test_safe_eval.py
index 62403e81e6c..3df214c3562 100644
--- a/test/units/module_utils/basic/test_safe_eval.py
+++ b/test/units/module_utils/basic/test_safe_eval.py
@@ -5,11 +5,14 @@
 from __future__ import annotations
 
 from itertools import chain
+
+import typing as t
+
 import pytest
 
 
 # Strings that should be converted into a typed value
-VALID_STRINGS = (
+VALID_STRINGS: tuple[tuple[str, t.Any], ...] = (
     ("'a'", 'a'),
     ("'1'", '1'),
     ("1", 1),
diff --git a/test/units/module_utils/common/arg_spec/test_aliases.py b/test/units/module_utils/common/arg_spec/test_aliases.py
index a7c82b03b49..34726465b84 100644
--- a/test/units/module_utils/common/arg_spec/test_aliases.py
+++ b/test/units/module_utils/common/arg_spec/test_aliases.py
@@ -67,7 +67,7 @@ ALIAS_TEST_CASES = [
 
 
 # id, argument spec, parameters, expected parameters, error
-ALIAS_TEST_CASES_INVALID = [
+ALIAS_TEST_CASES_INVALID: list[tuple[str, dict, dict, dict, str]] = [
     (
         "alias-invalid",
         {'path': {'aliases': 'bad'}},
diff --git a/test/units/module_utils/common/test_collections.py b/test/units/module_utils/common/test_collections.py
index 93cf3245ba4..381d583004c 100644
--- a/test/units/module_utils/common/test_collections.py
+++ b/test/units/module_utils/common/test_collections.py
@@ -39,16 +39,14 @@ class FakeAnsibleVaultEncryptedUnicode(Sequence):
 TEST_STRINGS = u'he', u'Україна', u'Česká republika'
 TEST_STRINGS = TEST_STRINGS + tuple(s.encode('utf-8') for s in TEST_STRINGS) + (FakeAnsibleVaultEncryptedUnicode(u'foo'),)
 
-TEST_ITEMS_NON_SEQUENCES = (
+TEST_ITEMS_NON_SEQUENCES: tuple = (
     {}, object(), frozenset(),
     4, 0.,
 ) + TEST_STRINGS
 
-TEST_ITEMS_SEQUENCES = (
+TEST_ITEMS_SEQUENCES: tuple = (
     [], (),
     SeqStub(),
-)
-TEST_ITEMS_SEQUENCES = TEST_ITEMS_SEQUENCES + (
     # Iterable effectively containing nested random data:
     TEST_ITEMS_NON_SEQUENCES,
 )
diff --git a/test/units/module_utils/facts/hardware/test_linux.py b/test/units/module_utils/facts/hardware/test_linux.py
index 0a546f1516b..74e8f20cd5d 100644
--- a/test/units/module_utils/facts/hardware/test_linux.py
+++ b/test/units/module_utils/facts/hardware/test_linux.py
@@ -29,8 +29,6 @@ from . linux_data import LSBLK_OUTPUT, LSBLK_OUTPUT_2, LSBLK_UUIDS, MTAB, MTAB_E
 with open(os.path.join(os.path.dirname(__file__), '../fixtures/findmount_output.txt')) as f:
     FINDMNT_OUTPUT = f.read()
 
-GET_MOUNT_SIZE = {}
-
 
 def mock_get_mount_size(mountpoint):
     return STATVFS_INFO.get(mountpoint, {})
diff --git a/test/units/module_utils/facts/test_ansible_collector.py b/test/units/module_utils/facts/test_ansible_collector.py
index badfddd9d8c..3293960d9f7 100644
--- a/test/units/module_utils/facts/test_ansible_collector.py
+++ b/test/units/module_utils/facts/test_ansible_collector.py
@@ -200,7 +200,7 @@ class TestCollectedFacts(unittest.TestCase):
                       'env']
     not_expected_facts = ['facter', 'ohai']
 
-    collected_facts = {}
+    collected_facts: dict[str, str] = {}
 
     def _mock_module(self, gather_subset=None):
         return mock_module(gather_subset=self.gather_subset)
diff --git a/test/units/modules/test_copy.py b/test/units/modules/test_copy.py
index 49e332429a1..6f15bed1223 100644
--- a/test/units/modules/test_copy.py
+++ b/test/units/modules/test_copy.py
@@ -11,102 +11,109 @@ from ansible.modules.copy import AnsibleModuleError, split_pre_existing_dir
 
 from ansible.module_utils.basic import AnsibleModule
 
+THREE_DIRS_DATA: tuple[tuple[str, tuple[str, list[str]] | None, tuple[str, list[str]], tuple[str, list[str]], tuple[str, list[str]]], ...] = (
+    ('/dir1/dir2',
+     # 0 existing dirs: error (because / should always exist)
+     None,
+     # 1 existing dir:
+     ('/', ['dir1', 'dir2']),
+     # 2 existing dirs:
+     ('/dir1', ['dir2']),
+     # 3 existing dirs:
+     ('/dir1/dir2', [])
+     ),
+    ('/dir1/dir2/',
+     # 0 existing dirs: error (because / should always exist)
+     None,
+     # 1 existing dir:
+     ('/', ['dir1', 'dir2']),
+     # 2 existing dirs:
+     ('/dir1', ['dir2']),
+     # 3 existing dirs:
+     ('/dir1/dir2', [])
+     ),
+)
+
 
-THREE_DIRS_DATA = (('/dir1/dir2',
-                    # 0 existing dirs: error (because / should always exist)
-                    None,
-                    # 1 existing dir:
-                    ('/', ['dir1', 'dir2']),
-                    # 2 existing dirs:
-                    ('/dir1', ['dir2']),
-                    # 3 existing dirs:
-                    ('/dir1/dir2', [])
-                    ),
-                   ('/dir1/dir2/',
-                    # 0 existing dirs: error (because / should always exist)
-                    None,
-                    # 1 existing dir:
-                    ('/', ['dir1', 'dir2']),
-                    # 2 existing dirs:
-                    ('/dir1', ['dir2']),
-                    # 3 existing dirs:
-                    ('/dir1/dir2', [])
-                    ),
-                   )
-
-
-TWO_DIRS_DATA = (('dir1/dir2',
-                  # 0 existing dirs:
-                  ('.', ['dir1', 'dir2']),
-                  # 1 existing dir:
-                  ('dir1', ['dir2']),
-                  # 2 existing dirs:
-                  ('dir1/dir2', []),
-                  # 3 existing dirs: Same as 2 because we never get to the third
-                  ),
-                 ('dir1/dir2/',
-                  # 0 existing dirs:
-                  ('.', ['dir1', 'dir2']),
-                  # 1 existing dir:
-                  ('dir1', ['dir2']),
-                  # 2 existing dirs:
-                  ('dir1/dir2', []),
-                  # 3 existing dirs: Same as 2 because we never get to the third
-                  ),
-                 ('/dir1',
-                  # 0 existing dirs: error (because / should always exist)
-                  None,
-                  # 1 existing dir:
-                  ('/', ['dir1']),
-                  # 2 existing dirs:
-                  ('/dir1', []),
-                  # 3 existing dirs: Same as 2 because we never get to the third
-                  ),
-                 ('/dir1/',
-                  # 0 existing dirs: error (because / should always exist)
-                  None,
-                  # 1 existing dir:
-                  ('/', ['dir1']),
-                  # 2 existing dirs:
-                  ('/dir1', []),
-                  # 3 existing dirs: Same as 2 because we never get to the third
-                  ),
-                 ) + THREE_DIRS_DATA
-
-
-ONE_DIR_DATA = (('dir1',
-                 # 0 existing dirs:
-                 ('.', ['dir1']),
-                 # 1 existing dir:
-                 ('dir1', []),
-                 # 2 existing dirs: Same as 1 because we never get to the third
-                 ),
-                ('dir1/',
-                 # 0 existing dirs:
-                 ('.', ['dir1']),
-                 # 1 existing dir:
-                 ('dir1', []),
-                 # 2 existing dirs: Same as 1 because we never get to the third
-                 ),
-                ) + TWO_DIRS_DATA
+TWO_DIRS_DATA: tuple[tuple[str, tuple[str, list[str]] | None, tuple[str, list[str]], tuple[str, list[str]]], ...] = (
+    ('dir1/dir2',
+     # 0 existing dirs:
+     ('.', ['dir1', 'dir2']),
+     # 1 existing dir:
+     ('dir1', ['dir2']),
+     # 2 existing dirs:
+     ('dir1/dir2', []),
+     # 3 existing dirs: Same as 2 because we never get to the third
+     ),
+    ('dir1/dir2/',
+     # 0 existing dirs:
+     ('.', ['dir1', 'dir2']),
+     # 1 existing dir:
+     ('dir1', ['dir2']),
+     # 2 existing dirs:
+     ('dir1/dir2', []),
+     # 3 existing dirs: Same as 2 because we never get to the third
+     ),
+    ('/dir1',
+     # 0 existing dirs: error (because / should always exist)
+     None,
+     # 1 existing dir:
+     ('/', ['dir1']),
+     # 2 existing dirs:
+     ('/dir1', []),
+     # 3 existing dirs: Same as 2 because we never get to the third
+     ),
+    ('/dir1/',
+     # 0 existing dirs: error (because / should always exist)
+     None,
+     # 1 existing dir:
+     ('/', ['dir1']),
+     # 2 existing dirs:
+     ('/dir1', []),
+     # 3 existing dirs: Same as 2 because we never get to the third
+     ),
+)
+TWO_DIRS_DATA += tuple(item[:4] for item in THREE_DIRS_DATA)
+
+
+ONE_DIR_DATA: tuple[tuple[str, tuple[str, list[str]] | None, tuple[str, list[str]]], ...] = (
+    ('dir1',
+     # 0 existing dirs:
+     ('.', ['dir1']),
+     # 1 existing dir:
+     ('dir1', []),
+     # 2 existing dirs: Same as 1 because we never get to the third
+     ),
+    ('dir1/',
+     # 0 existing dirs:
+     ('.', ['dir1']),
+     # 1 existing dir:
+     ('dir1', []),
+     # 2 existing dirs: Same as 1 because we never get to the third
+     ),
+)
+ONE_DIR_DATA += tuple(item[:3] for item in TWO_DIRS_DATA)
 
 
 @pytest.mark.parametrize('directory, expected', ((d[0], d[4]) for d in THREE_DIRS_DATA))
+@pytest.mark.xfail(reason='broken test and/or code, original test missing assert', strict=False)
 def test_split_pre_existing_dir_three_levels_exist(directory, expected, mocker):
     mocker.patch('os.path.exists', side_effect=[True, True, True])
-    split_pre_existing_dir(directory) == expected
+    assert split_pre_existing_dir(directory) == expected
 
 
 @pytest.mark.parametrize('directory, expected', ((d[0], d[3]) for d in TWO_DIRS_DATA))
+@pytest.mark.xfail(reason='broken test and/or code, original test missing assert', strict=False)
 def test_split_pre_existing_dir_two_levels_exist(directory, expected, mocker):
     mocker.patch('os.path.exists', side_effect=[True, True, False])
-    split_pre_existing_dir(directory) == expected
+    assert split_pre_existing_dir(directory) == expected
 
 
 @pytest.mark.parametrize('directory, expected', ((d[0], d[2]) for d in ONE_DIR_DATA))
+@pytest.mark.xfail(reason='broken test and/or code, original test missing assert', strict=False)
 def test_split_pre_existing_dir_one_level_exists(directory, expected, mocker):
     mocker.patch('os.path.exists', side_effect=[True, False, False])
-    split_pre_existing_dir(directory) == expected
+    assert split_pre_existing_dir(directory) == expected
 
 
 @pytest.mark.parametrize('directory', (d[0] for d in ONE_DIR_DATA if d[1] is None))
@@ -118,9 +125,10 @@ def test_split_pre_existing_dir_root_does_not_exist(directory, mocker):
 
 
 @pytest.mark.parametrize('directory, expected', ((d[0], d[1]) for d in ONE_DIR_DATA if not d[0].startswith('/')))
+@pytest.mark.xfail(reason='broken test and/or code, original test missing assert', strict=False)
 def test_split_pre_existing_dir_working_dir_exists(directory, expected, mocker):
     mocker.patch('os.path.exists', return_value=False)
-    split_pre_existing_dir(directory) == expected
+    assert split_pre_existing_dir(directory) == expected
 
 
 #
diff --git a/test/units/parsing/test_splitter.py b/test/units/parsing/test_splitter.py
index 9eb957d6969..402ee74dcb7 100644
--- a/test/units/parsing/test_splitter.py
+++ b/test/units/parsing/test_splitter.py
@@ -23,7 +23,7 @@ from ansible.errors import AnsibleParserError
 
 import pytest
 
-SPLIT_DATA = (
+SPLIT_DATA: tuple[tuple[str | None, list[str], dict[str, str]], ...] = (
     (None,
         [],
         {}),
diff --git a/test/units/plugins/connection/test_psrp.py b/test/units/plugins/connection/test_psrp.py
index 10902a15819..fcc5648d0fd 100644
--- a/test/units/plugins/connection/test_psrp.py
+++ b/test/units/plugins/connection/test_psrp.py
@@ -6,6 +6,7 @@ from __future__ import annotations
 
 import pytest
 import sys
+import typing as t
 
 from io import StringIO
 from unittest.mock import MagicMock
@@ -46,7 +47,7 @@ def psrp_connection():
 
 class TestConnectionPSRP(object):
 
-    OPTIONS_DATA = (
+    OPTIONS_DATA: tuple[tuple[dict[str, t.Any], dict[str, t.Any]], ...] = (
         # default options
         (
             {},
diff --git a/test/units/plugins/connection/test_winrm.py b/test/units/plugins/connection/test_winrm.py
index 00a29c97286..d5b76ca8f26 100644
--- a/test/units/plugins/connection/test_winrm.py
+++ b/test/units/plugins/connection/test_winrm.py
@@ -5,6 +5,7 @@
 from __future__ import annotations
 
 import os
+import typing as t
 
 import pytest
 
@@ -22,7 +23,7 @@ pytest.importorskip("winrm")
 
 class TestConnectionWinRM(object):
 
-    OPTIONS_DATA = (
+    OPTIONS_DATA: tuple[tuple[dict[str, t.Any], dict[str, t.Any], dict[str, t.Any], bool], ...] = (
         # default options
         (
             {'_extras': {}},
diff --git a/test/units/plugins/filter/test_mathstuff.py b/test/units/plugins/filter/test_mathstuff.py
index 4ac5487fa23..b473e305fda 100644
--- a/test/units/plugins/filter/test_mathstuff.py
+++ b/test/units/plugins/filter/test_mathstuff.py
@@ -11,7 +11,7 @@ import ansible.plugins.filter.mathstuff as ms
 from ansible.errors import AnsibleFilterError, AnsibleFilterTypeError
 
 
-UNIQUE_DATA = [
+UNIQUE_DATA: list[tuple[list, list]] = [
     ([], []),
     ([1, 3, 4, 2], [1, 3, 4, 2]),
     ([1, 3, 2, 4, 2, 3], [1, 3, 2, 4]),
@@ -19,7 +19,7 @@ UNIQUE_DATA = [
     ([1, 1, 4, 2, 1, 4, 3, 2], [1, 4, 2, 3]),
 ]
 
-TWO_SETS_DATA = [
+TWO_SETS_DATA: list[tuple[list, list, tuple]] = [
     ([], [], ([], [], [])),
     ([1, 2], [1, 2], ([1, 2], [], [])),
     ([1, 2], [3, 4], ([], [1, 2], [1, 2, 3, 4])),
diff --git a/test/units/plugins/lookup/test_password.py b/test/units/plugins/lookup/test_password.py
index d615be998ec..46c63db6032 100644
--- a/test/units/plugins/lookup/test_password.py
+++ b/test/units/plugins/lookup/test_password.py
@@ -387,8 +387,11 @@ class TestWritePasswordFile(unittest.TestCase):
     def setUp(self):
         self.makedirs_safe = password.makedirs_safe
         self.os_chmod = password.os.chmod
-        password.makedirs_safe = lambda path, mode: None
-        password.os.chmod = lambda path, mode: None
+        password.makedirs_safe = self.noop
+        password.os.chmod = self.noop
+
+    def noop(self, *args, **kwargs):
+        pass
 
     def tearDown(self):
         password.makedirs_safe = self.makedirs_safe
@@ -410,11 +413,14 @@ class BaseTestLookupModule(unittest.TestCase):
         self.password_lookup._loader = self.fake_loader
         self.os_path_exists = password.os.path.exists
         self.os_open = password.os.open
-        password.os.open = lambda path, flag: None
+        password.os.open = self.noop
         self.os_close = password.os.close
-        password.os.close = lambda fd: None
+        password.os.close = self.noop
         self.makedirs_safe = password.makedirs_safe
-        password.makedirs_safe = lambda path, mode: None
+        password.makedirs_safe = self.noop
+
+    def noop(self, *args, **kwargs):
+        pass
 
     def tearDown(self):
         password.os.path.exists = self.os_path_exists