diff --git a/moto/core/responses.py b/moto/core/responses.py
index 828370973..d6c17de00 100644
--- a/moto/core/responses.py
+++ b/moto/core/responses.py
@@ -6,6 +6,7 @@ import os
 import re
 from collections import OrderedDict, defaultdict
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     ClassVar,
@@ -41,6 +42,13 @@ log = logging.getLogger(__name__)
 
 JINJA_ENVS: Dict[type, Environment] = {}
 
+if TYPE_CHECKING:
+    from typing_extensions import ParamSpec
+
+    P = ParamSpec("P")
+
+T = TypeVar("T")
+
 
 ResponseShape = TypeVar("ResponseShape", bound="BaseResponse")
 
@@ -173,13 +181,13 @@ class ActionAuthenticatorMixin(object):
         self._authenticate_and_authorize_action(S3IAMRequest, resource)
 
     @staticmethod
-    def set_initial_no_auth_action_count(initial_no_auth_action_count: int) -> Callable[..., Callable[..., TYPE_RESPONSE]]:  # type: ignore[misc]
+    def set_initial_no_auth_action_count(
+        initial_no_auth_action_count: int,
+    ) -> "Callable[[Callable[P, T]], Callable[P, T]]":
         _test_server_mode_endpoint = settings.test_server_mode_endpoint()
 
-        def decorator(
-            function: Callable[..., TYPE_RESPONSE]
-        ) -> Callable[..., TYPE_RESPONSE]:
-            def wrapper(*args: Any, **kwargs: Any) -> TYPE_RESPONSE:
+        def decorator(function: "Callable[P, T]") -> "Callable[P, T]":
+            def wrapper(*args: "P.args", **kwargs: "P.kwargs") -> T:
                 if settings.TEST_SERVER_MODE:
                     response = requests.post(
                         f"{_test_server_mode_endpoint}/moto-api/reset-auth",
diff --git a/setup.cfg b/setup.cfg
index 5b7d5abf9..774641da3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -277,7 +277,7 @@ disable = W,C,R,E
 enable = anomalous-backslash-in-string, arguments-renamed, dangerous-default-value, deprecated-module, function-redefined, import-self, redefined-builtin, redefined-outer-name, reimported, pointless-statement, super-with-arguments, unused-argument, unused-import, unused-variable, useless-else-on-loop, wildcard-import
 
 [mypy]
-files= moto, tests/test_core/test_mock_all.py, tests/test_core/test_decorator_calls.py, tests/test_core/test_responses_module.py, tests/test_core/test_mypy.py
+files= moto, tests/test_core/
 show_column_numbers=True
 show_error_codes = True
 disable_error_code=abstract
diff --git a/tests/test_core/test_account_id_resolution.py b/tests/test_core/test_account_id_resolution.py
index 4f008ca24..12dd1f523 100644
--- a/tests/test_core/test_account_id_resolution.py
+++ b/tests/test_core/test_account_id_resolution.py
@@ -1,4 +1,5 @@
 import os
+from typing import Dict, Optional
 from unittest import SkipTest
 
 import requests
@@ -13,7 +14,7 @@ BASE_URL = f"http://localhost:{SERVER_PORT}/"
 
 
 class TestAccountIdResolution:
-    def setup_method(self):
+    def setup_method(self) -> None:
         if settings.TEST_SERVER_MODE:
             raise SkipTest(
                 "No point in testing this in ServerMode, as we already start our own server"
@@ -21,10 +22,10 @@ class TestAccountIdResolution:
         self.server = ThreadedMotoServer(port=SERVER_PORT, verbose=False)
         self.server.start()
 
-    def teardown_method(self):
+    def teardown_method(self) -> None:
         self.server.stop()
 
-    def test_environment_variable_takes_precedence(self):
+    def test_environment_variable_takes_precedence(self) -> None:
         # Verify ACCOUNT ID is standard
         resp = self._get_caller_identity()
         assert self._get_account_id(resp) == ACCOUNT_ID
@@ -51,7 +52,9 @@ class TestAccountIdResolution:
         resp = self._get_caller_identity()
         assert self._get_account_id(resp) == ACCOUNT_ID
 
-    def _get_caller_identity(self, extra_headers=None):
+    def _get_caller_identity(
+        self, extra_headers: Optional[Dict[str, str]] = None
+    ) -> requests.Response:
         data = "Action=GetCallerIdentity&Version=2011-06-15"
         headers = {
             "Authorization": "AWS4-HMAC-SHA256 Credential=abcd/20010101/us-east-2/sts/aws4_request, SignedHeaders=host;x-amz-content-sha256;x-amz-date, Signature=...",
@@ -61,6 +64,6 @@ class TestAccountIdResolution:
         headers.update(extra_headers or {})
         return requests.post(f"{BASE_URL}", headers=headers, data=data)
 
-    def _get_account_id(self, resp):
+    def _get_account_id(self, resp: requests.Response) -> str:
         data = xmltodict.parse(resp.content)
         return data["GetCallerIdentityResponse"]["GetCallerIdentityResult"]["Account"]
diff --git a/tests/test_core/test_auth.py b/tests/test_core/test_auth.py
index 04b77ce14..3376d94d5 100644
--- a/tests/test_core/test_auth.py
+++ b/tests/test_core/test_auth.py
@@ -1,4 +1,5 @@
 import json
+from typing import Any, Dict, Optional
 from uuid import uuid4
 
 import boto3
@@ -11,16 +12,16 @@ from moto.core import set_initial_no_auth_action_count
 
 
 @mock_iam
-def create_user_with_access_key(user_name="test-user"):
+def create_user_with_access_key(user_name: str = "test-user") -> Dict[str, str]:
     client = boto3.client("iam", region_name="us-east-1")
     client.create_user(UserName=user_name)
     return client.create_access_key(UserName=user_name)["AccessKey"]
 
 
 @mock_iam
-def create_user_with_access_key_and_inline_policy(
-    user_name, policy_document, policy_name="policy1"
-):
+def create_user_with_access_key_and_inline_policy(  # type: ignore[misc]
+    user_name: str, policy_document: Dict[str, Any], policy_name: str = "policy1"
+) -> Dict[str, str]:
     client = boto3.client("iam", region_name="us-east-1")
     client.create_user(UserName=user_name)
     client.put_user_policy(
@@ -32,9 +33,9 @@ def create_user_with_access_key_and_inline_policy(
 
 
 @mock_iam
-def create_user_with_access_key_and_attached_policy(
-    user_name, policy_document, policy_name="policy1"
-):
+def create_user_with_access_key_and_attached_policy(  # type: ignore[misc]
+    user_name: str, policy_document: Dict[str, Any], policy_name: str = "policy1"
+) -> Dict[str, str]:
     client = boto3.client("iam", region_name="us-east-1")
     client.create_user(UserName=user_name)
     policy_arn = client.create_policy(
@@ -45,13 +46,13 @@ def create_user_with_access_key_and_attached_policy(
 
 
 @mock_iam
-def create_user_with_access_key_and_multiple_policies(
-    user_name,
-    inline_policy_document,
-    attached_policy_document,
-    inline_policy_name="policy1",
-    attached_policy_name="policy1",
-):
+def create_user_with_access_key_and_multiple_policies(  # type: ignore[misc]
+    user_name: str,
+    inline_policy_document: Dict[str, Any],
+    attached_policy_document: Dict[str, Any],
+    inline_policy_name: str = "policy1",
+    attached_policy_name: str = "policy1",
+) -> Dict[str, str]:
     client = boto3.client("iam", region_name="us-east-1")
     client.create_user(UserName=user_name)
     policy_arn = client.create_policy(
@@ -68,8 +69,11 @@ def create_user_with_access_key_and_multiple_policies(
 
 
 def create_group_with_attached_policy_and_add_user(
-    user_name, policy_document, group_name="test-group", policy_name=None
-):
+    user_name: str,
+    policy_document: Dict[str, Any],
+    group_name: str = "test-group",
+    policy_name: Optional[str] = None,
+) -> None:
     if not policy_name:
         policy_name = str(uuid4())
     client = boto3.client("iam", region_name="us-east-1")
@@ -82,8 +86,11 @@ def create_group_with_attached_policy_and_add_user(
 
 
 def create_group_with_inline_policy_and_add_user(
-    user_name, policy_document, group_name="test-group", policy_name="policy1"
-):
+    user_name: str,
+    policy_document: Dict[str, Any],
+    group_name: str = "test-group",
+    policy_name: str = "policy1",
+) -> None:
     client = boto3.client("iam", region_name="us-east-1")
     client.create_group(GroupName=group_name)
     client.put_group_policy(
@@ -95,13 +102,13 @@ def create_group_with_inline_policy_and_add_user(
 
 
 def create_group_with_multiple_policies_and_add_user(
-    user_name,
-    inline_policy_document,
-    attached_policy_document,
-    group_name="test-group",
-    inline_policy_name="policy1",
-    attached_policy_name=None,
-):
+    user_name: str,
+    inline_policy_document: Dict[str, Any],
+    attached_policy_document: Dict[str, Any],
+    group_name: str = "test-group",
+    inline_policy_name: str = "policy1",
+    attached_policy_name: Optional[str] = None,
+) -> None:
     if not attached_policy_name:
         attached_policy_name = str(uuid4())
     client = boto3.client("iam", region_name="us-east-1")
@@ -121,13 +128,13 @@ def create_group_with_multiple_policies_and_add_user(
 
 @mock_iam
 @mock_sts
-def create_role_with_attached_policy_and_assume_it(
-    role_name,
-    trust_policy_document,
-    policy_document,
-    session_name="session1",
-    policy_name="policy1",
-):
+def create_role_with_attached_policy_and_assume_it(  # type: ignore[misc]
+    role_name: str,
+    trust_policy_document: Dict[str, Any],
+    policy_document: Dict[str, Any],
+    session_name: str = "session1",
+    policy_name: str = "policy1",
+) -> Dict[str, str]:
     iam_client = boto3.client("iam", region_name="us-east-1")
     sts_client = boto3.client("sts", region_name="us-east-1")
     role_arn = iam_client.create_role(
@@ -144,13 +151,13 @@ def create_role_with_attached_policy_and_assume_it(
 
 @mock_iam
 @mock_sts
-def create_role_with_inline_policy_and_assume_it(
-    role_name,
-    trust_policy_document,
-    policy_document,
-    session_name="session1",
-    policy_name="policy1",
-):
+def create_role_with_inline_policy_and_assume_it(  # type: ignore[misc]
+    role_name: str,
+    trust_policy_document: Dict[str, Any],
+    policy_document: Dict[str, Any],
+    session_name: str = "session1",
+    policy_name: str = "policy1",
+) -> Dict[str, str]:
     iam_client = boto3.client("iam", region_name="us-east-1")
     sts_client = boto3.client("sts", region_name="us-east-1")
     role_arn = iam_client.create_role(
@@ -168,7 +175,7 @@ def create_role_with_inline_policy_and_assume_it(
 
 @set_initial_no_auth_action_count(0)
 @mock_iam
-def test_invalid_client_token_id():
+def test_invalid_client_token_id() -> None:
     client = boto3.client(
         "iam",
         region_name="us-east-1",
@@ -185,7 +192,7 @@ def test_invalid_client_token_id():
 
 @set_initial_no_auth_action_count(0)
 @mock_ec2
-def test_auth_failure():
+def test_auth_failure() -> None:
     client = boto3.client(
         "ec2",
         region_name="us-east-1",
@@ -204,7 +211,7 @@ def test_auth_failure():
 
 @set_initial_no_auth_action_count(2)
 @mock_iam
-def test_signature_does_not_match():
+def test_signature_does_not_match() -> None:
     access_key = create_user_with_access_key()
     client = boto3.client(
         "iam",
@@ -224,7 +231,7 @@ def test_signature_does_not_match():
 
 @set_initial_no_auth_action_count(2)
 @mock_ec2
-def test_auth_failure_with_valid_access_key_id():
+def test_auth_failure_with_valid_access_key_id() -> None:
     access_key = create_user_with_access_key()
     client = boto3.client(
         "ec2",
@@ -244,7 +251,7 @@ def test_auth_failure_with_valid_access_key_id():
 
 @set_initial_no_auth_action_count(2)
 @mock_ec2
-def test_access_denied_with_no_policy():
+def test_access_denied_with_no_policy() -> None:
     user_name = "test-user"
     access_key = create_user_with_access_key(user_name)
     client = boto3.client(
@@ -265,7 +272,7 @@ def test_access_denied_with_no_policy():
 
 @set_initial_no_auth_action_count(3)
 @mock_ec2
-def test_access_denied_with_not_allowing_policy():
+def test_access_denied_with_not_allowing_policy() -> None:
     user_name = "test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -292,7 +299,7 @@ def test_access_denied_with_not_allowing_policy():
 
 @set_initial_no_auth_action_count(3)
 @mock_sts
-def test_access_denied_explicitly_on_specific_resource():
+def test_access_denied_explicitly_on_specific_resource() -> None:
     user_name = "test-user"
     forbidden_role_arn = f"arn:aws:iam::{ACCOUNT_ID}:role/forbidden_explicitly"
     allowed_role_arn = f"arn:aws:iam::{ACCOUNT_ID}:role/allowed_implictly"
@@ -333,7 +340,7 @@ def test_access_denied_explicitly_on_specific_resource():
 
 @set_initial_no_auth_action_count(3)
 @mock_ec2
-def test_access_denied_for_run_instances():
+def test_access_denied_for_run_instances() -> None:
     # https://github.com/getmoto/moto/issues/2774
     # The run-instances method was broken between botocore versions 1.15.8 and 1.15.12
     # This was due to the inclusion of '"idempotencyToken":true' in the response, somehow altering the signature and breaking the authentication
@@ -366,7 +373,7 @@ def test_access_denied_for_run_instances():
 
 @set_initial_no_auth_action_count(3)
 @mock_ec2
-def test_access_denied_with_denying_policy():
+def test_access_denied_with_denying_policy() -> None:
     user_name = "test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -396,7 +403,7 @@ def test_access_denied_with_denying_policy():
 
 @set_initial_no_auth_action_count(3)
 @mock_sts
-def test_get_caller_identity_allowed_with_denying_policy():
+def test_get_caller_identity_allowed_with_denying_policy() -> None:
     user_name = "test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -421,7 +428,7 @@ def test_get_caller_identity_allowed_with_denying_policy():
 
 @set_initial_no_auth_action_count(3)
 @mock_ec2
-def test_allowed_with_wildcard_action():
+def test_allowed_with_wildcard_action() -> None:
     user_name = "test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -441,7 +448,7 @@ def test_allowed_with_wildcard_action():
 
 @set_initial_no_auth_action_count(4)
 @mock_iam
-def test_allowed_with_explicit_action_in_attached_policy():
+def test_allowed_with_explicit_action_in_attached_policy() -> None:
     user_name = "test-user"
     attached_policy_document = {
         "Version": "2012-10-17",
@@ -462,7 +469,7 @@ def test_allowed_with_explicit_action_in_attached_policy():
 @set_initial_no_auth_action_count(8)
 @mock_s3
 @mock_iam
-def test_s3_access_denied_with_denying_attached_group_policy():
+def test_s3_access_denied_with_denying_attached_group_policy() -> None:
     user_name = "test-user"
     attached_policy_document = {
         "Version": "2012-10-17",
@@ -496,7 +503,7 @@ def test_s3_access_denied_with_denying_attached_group_policy():
 @set_initial_no_auth_action_count(6)
 @mock_s3
 @mock_iam
-def test_s3_access_denied_with_denying_inline_group_policy():
+def test_s3_access_denied_with_denying_inline_group_policy() -> None:
     user_name = "test-user"
     bucket_name = "test-bucket"
     inline_policy_document = {
@@ -530,7 +537,7 @@ def test_s3_access_denied_with_denying_inline_group_policy():
 @set_initial_no_auth_action_count(10)
 @mock_iam
 @mock_ec2
-def test_access_denied_with_many_irrelevant_policies():
+def test_access_denied_with_many_irrelevant_policies() -> None:
     user_name = "test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -581,7 +588,7 @@ def test_access_denied_with_many_irrelevant_policies():
 @mock_sts
 @mock_ec2
 @mock_elbv2
-def test_allowed_with_temporary_credentials():
+def test_allowed_with_temporary_credentials() -> None:
     role_name = "test-role"
     trust_policy_document = {
         "Version": "2012-10-17",
@@ -632,7 +639,7 @@ def test_allowed_with_temporary_credentials():
 @mock_iam
 @mock_sts
 @mock_rds
-def test_access_denied_with_temporary_credentials():
+def test_access_denied_with_temporary_credentials() -> None:
     role_name = "test-role"
     session_name = "test-session"
     trust_policy_document = {
@@ -675,7 +682,7 @@ def test_access_denied_with_temporary_credentials():
 
 @set_initial_no_auth_action_count(3)
 @mock_iam
-def test_get_user_from_credentials():
+def test_get_user_from_credentials() -> None:
     user_name = "new-test-user"
     inline_policy_document = {
         "Version": "2012-10-17",
@@ -695,7 +702,7 @@ def test_get_user_from_credentials():
 
 @set_initial_no_auth_action_count(0)
 @mock_s3
-def test_s3_invalid_access_key_id():
+def test_s3_invalid_access_key_id() -> None:
     client = boto3.client(
         "s3",
         region_name="us-east-1",
@@ -715,7 +722,7 @@ def test_s3_invalid_access_key_id():
 @set_initial_no_auth_action_count(3)
 @mock_s3
 @mock_iam
-def test_s3_signature_does_not_match():
+def test_s3_signature_does_not_match() -> None:
     bucket_name = "test-bucket"
     access_key = create_user_with_access_key()
     client = boto3.client(
@@ -738,7 +745,7 @@ def test_s3_signature_does_not_match():
 @set_initial_no_auth_action_count(7)
 @mock_s3
 @mock_iam
-def test_s3_access_denied_not_action():
+def test_s3_access_denied_not_action() -> None:
     user_name = "test-user"
     bucket_name = "test-bucket"
     inline_policy_document = {
@@ -773,7 +780,7 @@ def test_s3_access_denied_not_action():
 @mock_iam
 @mock_sts
 @mock_s3
-def test_s3_invalid_token_with_temporary_credentials():
+def test_s3_invalid_token_with_temporary_credentials() -> None:
     role_name = "test-role"
     session_name = "test-session"
     bucket_name = "test-bucket-888"
@@ -876,17 +883,11 @@ def test_allow_key_access_using_resource_arn() -> None:
 @set_initial_no_auth_action_count(3)
 @mock_ssm
 @mock_iam
-def test_ssm_service():
+def test_ssm_service() -> None:
     user_name = "test-user"
     policy_doc = {
         "Version": "2012-10-17",
-        "Statement": [
-            {
-                "Action": ["ssm:*"],
-                "Effect": "Allow",
-                "Resource": ["*"],
-            },
-        ],
+        "Statement": [{"Action": ["ssm:*"], "Effect": "Allow", "Resource": ["*"]}],
     }
     access_key = create_user_with_access_key_and_inline_policy(user_name, policy_doc)
 
diff --git a/tests/test_core/test_backenddict.py b/tests/test_core/test_backenddict.py
index e56a5a8d3..1044ff9cb 100644
--- a/tests/test_core/test_backenddict.py
+++ b/tests/test_core/test_backenddict.py
@@ -1,6 +1,7 @@
 import random
 import time
 from threading import Thread
+from typing import Any, List, Optional
 
 import pytest
 
@@ -12,32 +13,32 @@ from moto.elbv2.models import ELBv2Backend
 
 
 class ExampleBackend(BaseBackend):
-    def __init__(self, region_name, account_id):
+    def __init__(self, region_name: str, account_id: str):
         super().__init__(region_name, account_id)
 
 
-def test_backend_dict_returns_nothing_by_default():
+def test_backend_dict_returns_nothing_by_default() -> None:
     backend_dict = BackendDict(ExampleBackend, "ebs")
     assert list(backend_dict.items()) == []
 
 
-def test_account_specific_dict_contains_known_regions():
+def test_account_specific_dict_contains_known_regions() -> None:
     backend_dict = BackendDict(ExampleBackend, "ec2")
     assert isinstance(backend_dict["account"]["eu-north-1"], ExampleBackend)
 
 
-def test_backend_dict_does_not_contain_unknown_regions():
+def test_backend_dict_does_not_contain_unknown_regions() -> None:
     backend_dict = BackendDict(ExampleBackend, "ec2")
     assert "mars-south-1" not in backend_dict["account"]
 
 
-def test_backend_dict_fails_when_retrieving_unknown_regions():
+def test_backend_dict_fails_when_retrieving_unknown_regions() -> None:
     backend_dict = BackendDict(ExampleBackend, "ec2")
     with pytest.raises(KeyError):
         backend_dict["account"]["mars-south-1"]  # pylint: disable=pointless-statement
 
 
-def test_backend_dict_can_retrieve_for_specific_account():
+def test_backend_dict_can_retrieve_for_specific_account() -> None:
     backend_dict = BackendDict(ExampleBackend, "ec2")
 
     # Random account does not exist
@@ -55,12 +56,12 @@ def test_backend_dict_can_retrieve_for_specific_account():
     assert regional_backend.account_id == "012345"
 
 
-def test_backend_dict_can_ignore_boto3_regions():
+def test_backend_dict_can_ignore_boto3_regions() -> None:
     backend_dict = BackendDict(ExampleBackend, "ec2", use_boto3_regions=False)
     assert backend_dict["account"].get("us-east-1") is None
 
 
-def test_backend_dict_can_specify_additional_regions():
+def test_backend_dict_can_specify_additional_regions() -> None:
     backend_dict = BackendDict(
         ExampleBackend, "ec2", additional_regions=["region1", "global"]
     )["123456"]
@@ -74,15 +75,15 @@ def test_backend_dict_can_specify_additional_regions():
 
 class TestMultiThreadedAccess:
     class SlowExampleBackend(BaseBackend):
-        def __init__(self, region_name, account_id):
+        def __init__(self, region_name: str, account_id: str):
             super().__init__(region_name, account_id)
             time.sleep(0.1)
-            self.data = []
+            self.data: List[int] = []
 
-    def setup_method(self):
+    def setup_method(self) -> None:
         self.backend = BackendDict(TestMultiThreadedAccess.SlowExampleBackend, "ec2")
 
-    def test_access_a_slow_backend_concurrently(self):
+    def test_access_a_slow_backend_concurrently(self) -> None:
         """None
         Usecase that we want to avoid:
 
@@ -103,7 +104,7 @@ class TestMultiThreadedAccess:
         Thread 2 adds a new value to the list
         """
 
-        def access(random_number):
+        def access(random_number: int) -> None:
             self.backend["123456789012"]["us-east-1"].data.append(random_number)
 
         threads = []
@@ -119,7 +120,7 @@ class TestMultiThreadedAccess:
         assert len(self.backend["123456789012"]["us-east-1"].data) == 15
 
 
-def test_backend_dict_can_be_hashed():
+def test_backend_dict_can_be_hashed() -> None:
     hashes = []
     for backend in [ExampleBackend, set, list, BaseBackend]:
         hashes.append(BackendDict(backend, "n/a").__hash__())
@@ -127,7 +128,7 @@ def test_backend_dict_can_be_hashed():
     assert len(set(hashes)) == 4
 
 
-def test_account_specific_dict_can_be_hashed():
+def test_account_specific_dict_can_be_hashed() -> None:
     hashes = []
     ids = ["01234567912", "01234567911", "01234567913", "000000000000", "0"]
     for accnt_id in ids:
@@ -137,7 +138,12 @@ def test_account_specific_dict_can_be_hashed():
     assert len(set(hashes)) == 5
 
 
-def _create_asb(account_id, backend=None, use_boto3_regions=False, regions=None):
+def _create_asb(
+    account_id: str,
+    backend: Any = None,
+    use_boto3_regions: bool = False,
+    regions: Optional[List[str]] = None,
+) -> Any:
     return AccountSpecificBackend(
         service_name="ec2",
         account_id=account_id,
@@ -147,7 +153,7 @@ def _create_asb(account_id, backend=None, use_boto3_regions=False, regions=None)
     )
 
 
-def test_multiple_backends_cache_behaviour():
+def test_multiple_backends_cache_behaviour() -> None:
     ec2 = BackendDict(EC2Backend, "ec2")
     ec2_useast1 = ec2[DEFAULT_ACCOUNT_ID]["us-east-1"]
     assert type(ec2_useast1) == EC2Backend
@@ -172,7 +178,7 @@ def test_multiple_backends_cache_behaviour():
     assert type(as_1) == AutoScalingBackend
 
 
-def test_backenddict_cache_hits_and_misses():
+def test_backenddict_cache_hits_and_misses() -> None:
     backend = BackendDict(ExampleBackend, "ebs")
     backend.__getitem__.cache_clear()
 
@@ -213,7 +219,7 @@ def test_backenddict_cache_hits_and_misses():
     assert backend.__getitem__.cache_info().currsize == 2
 
 
-def test_asb_cache_hits_and_misses():
+def test_asb_cache_hits_and_misses() -> None:
     backend = BackendDict(ExampleBackend, "ebs")
     acb = backend["accnt_id"]
     acb.__getitem__.cache_clear()
diff --git a/tests/test_core/test_context_manager.py b/tests/test_core/test_context_manager.py
index f471716ae..8e7592ca9 100644
--- a/tests/test_core/test_context_manager.py
+++ b/tests/test_core/test_context_manager.py
@@ -4,11 +4,11 @@ from moto import mock_sqs, settings
 from tests import DEFAULT_ACCOUNT_ID
 
 
-def test_context_manager_returns_mock():
+def test_context_manager_returns_mock() -> None:
     with mock_sqs() as sqs_mock:
         conn = boto3.client("sqs", region_name="us-west-1")
         conn.create_queue(QueueName="queue1")
 
         if not settings.TEST_SERVER_MODE:
             backend = sqs_mock.backends[DEFAULT_ACCOUNT_ID]["us-west-1"]
-            assert list(backend.queues.keys()) == ["queue1"]
+            assert list(backend.queues.keys()) == ["queue1"]  # type: ignore[attr-defined]
diff --git a/tests/test_core/test_docker.py b/tests/test_core/test_docker.py
index 272227b6b..771250cab 100644
--- a/tests/test_core/test_docker.py
+++ b/tests/test_core/test_docker.py
@@ -9,7 +9,7 @@ logger = logging.getLogger(__name__)
 
 @requires_docker
 @pytest.mark.order(0)
-def test_docker_package_is_available():
+def test_docker_package_is_available() -> None:
     try:
         import docker  # noqa: F401   # pylint: disable=unused-import
     except ImportError as err:
@@ -22,7 +22,7 @@ def test_docker_package_is_available():
 
 @requires_docker
 @pytest.mark.order(0)
-def test_docker_is_running_and_available():
+def test_docker_is_running_and_available() -> None:
     import docker
     from docker.errors import DockerException
 
diff --git a/tests/test_core/test_ec2_vpc_endpoint_services.py b/tests/test_core/test_ec2_vpc_endpoint_services.py
index 8813067b1..2f58d5d77 100644
--- a/tests/test_core/test_ec2_vpc_endpoint_services.py
+++ b/tests/test_core/test_ec2_vpc_endpoint_services.py
@@ -11,7 +11,7 @@ from moto import mock_ec2
 
 
 @mock_ec2
-def test_describe_vpc_endpoint_services_bad_args():
+def test_describe_vpc_endpoint_services_bad_args() -> None:
     """Verify exceptions are raised for bad arguments."""
     ec2 = boto3.client("ec2", region_name="us-west-1")
 
@@ -47,7 +47,7 @@ def test_describe_vpc_endpoint_services_bad_args():
 
 
 @mock_ec2
-def test_describe_vpc_default_endpoint_services():
+def test_describe_vpc_default_endpoint_services() -> None:
     """Test successfull calls as well as the next_token arg."""
     ec2 = boto3.client("ec2", region_name="us-west-1")
 
diff --git a/tests/test_core/test_environ_patching.py b/tests/test_core/test_environ_patching.py
index b852443da..a0bbc7261 100644
--- a/tests/test_core/test_environ_patching.py
+++ b/tests/test_core/test_environ_patching.py
@@ -5,13 +5,13 @@ from moto import mock_ec2, mock_s3
 KEY = "AWS_ACCESS_KEY_ID"
 
 
-def test_aws_keys_are_patched():
+def test_aws_keys_are_patched() -> None:
     with mock_ec2():
         patched_value = os.environ[KEY]
         assert patched_value == "FOOBARKEY"
 
 
-def test_aws_keys_can_be_none():
+def test_aws_keys_can_be_none() -> None:
     """
     Verify that the os.environ[KEY] can be None
     Patching the None-value shouldn't be an issue
diff --git a/tests/test_core/test_importorder.py b/tests/test_core/test_importorder.py
index 504374060..0f649b5a8 100644
--- a/tests/test_core/test_importorder.py
+++ b/tests/test_core/test_importorder.py
@@ -1,3 +1,4 @@
+from typing import Any, List
 from unittest import SkipTest
 
 import boto3
@@ -7,7 +8,7 @@ from moto import mock_s3, settings
 
 
 @pytest.fixture(scope="function", name="aws_credentials")
-def fixture_aws_credentials(monkeypatch):
+def fixture_aws_credentials(monkeypatch: Any) -> None:  # type: ignore[misc]
     """Mocked AWS Credentials for moto."""
     if settings.TEST_SERVER_MODE:
         raise SkipTest("No point in testing this in ServerMode.")
@@ -18,8 +19,8 @@ def fixture_aws_credentials(monkeypatch):
 
 
 def test_mock_works_with_client_created_inside(
-    aws_credentials,
-):  # pylint: disable=unused-argument
+    aws_credentials: Any,  # pylint: disable=unused-argument
+) -> None:
     m = mock_s3()
     m.start()
     client = boto3.client("s3", region_name="us-east-1")
@@ -30,8 +31,8 @@ def test_mock_works_with_client_created_inside(
 
 
 def test_mock_works_with_client_created_outside(
-    aws_credentials,
-):  # pylint: disable=unused-argument
+    aws_credentials: Any,  # pylint: disable=unused-argument
+) -> None:
     # Create the boto3 client first
     outside_client = boto3.client("s3", region_name="us-east-1")
 
@@ -50,8 +51,8 @@ def test_mock_works_with_client_created_outside(
 
 
 def test_mock_works_with_resource_created_outside(
-    aws_credentials,
-):  # pylint: disable=unused-argument
+    aws_credentials: Any,  # pylint: disable=unused-argument
+) -> None:
     # Create the boto3 client first
     outside_resource = boto3.resource("s3", region_name="us-east-1")
 
@@ -68,7 +69,7 @@ def test_mock_works_with_resource_created_outside(
     m.stop()
 
 
-def test_patch_can_be_called_on_a_mocked_client():
+def test_patch_can_be_called_on_a_mocked_client() -> None:
     # start S3 after the mock, ensuring that the client contains our event-handler
     m = mock_s3()
     m.start()
@@ -90,14 +91,14 @@ def test_patch_can_be_called_on_a_mocked_client():
     m.stop()
 
 
-def test_patch_client_does_not_work_for_random_parameters():
+def test_patch_client_does_not_work_for_random_parameters() -> None:
     from moto.core import patch_client
 
     with pytest.raises(Exception, match="Argument sth should be of type boto3.client"):
-        patch_client("sth")
+        patch_client("sth")  # type: ignore[arg-type]
 
 
-def test_patch_resource_does_not_work_for_random_parameters():
+def test_patch_resource_does_not_work_for_random_parameters() -> None:
     from moto.core import patch_resource
 
     with pytest.raises(
@@ -107,16 +108,16 @@ def test_patch_resource_does_not_work_for_random_parameters():
 
 
 class ImportantBusinessLogic:
-    def __init__(self):
+    def __init__(self) -> None:
         self._s3 = boto3.client("s3", region_name="us-east-1")
 
-    def do_important_things(self):
+    def do_important_things(self) -> List[str]:
         return self._s3.list_buckets()["Buckets"]
 
 
 def test_mock_works_when_replacing_client(
-    aws_credentials,
-):  # pylint: disable=unused-argument
+    aws_credentials: Any,  # pylint: disable=unused-argument
+) -> None:
     logic = ImportantBusinessLogic()
 
     m = mock_s3()
diff --git a/tests/test_core/test_instance_metadata.py b/tests/test_core/test_instance_metadata.py
index f1af31283..0fcb4a47d 100644
--- a/tests/test_core/test_instance_metadata.py
+++ b/tests/test_core/test_instance_metadata.py
@@ -9,13 +9,13 @@ else:
 
 
 @mock_ec2
-def test_latest_meta_data():
+def test_latest_meta_data() -> None:
     res = requests.get(f"{BASE_URL}/latest/meta-data/")
     assert res.content == b"iam"
 
 
 @mock_ec2
-def test_meta_data_iam():
+def test_meta_data_iam() -> None:
     res = requests.get(f"{BASE_URL}/latest/meta-data/iam")
     json_response = res.json()
     default_role = json_response["security-credentials"]["default-role"]
@@ -26,13 +26,13 @@ def test_meta_data_iam():
 
 
 @mock_ec2
-def test_meta_data_security_credentials():
+def test_meta_data_security_credentials() -> None:
     res = requests.get(f"{BASE_URL}/latest/meta-data/iam/security-credentials/")
     assert res.content == b"default-role"
 
 
 @mock_ec2
-def test_meta_data_default_role():
+def test_meta_data_default_role() -> None:
     res = requests.get(
         f"{BASE_URL}/latest/meta-data/iam/security-credentials/default-role"
     )
diff --git a/tests/test_core/test_mock_regions.py b/tests/test_core/test_mock_regions.py
index 7128b5b67..5b7f89840 100644
--- a/tests/test_core/test_mock_regions.py
+++ b/tests/test_core/test_mock_regions.py
@@ -8,7 +8,7 @@ from moto import mock_dynamodb, mock_sns, settings
 
 
 @mock_sns
-def test_use_invalid_region():
+def test_use_invalid_region() -> None:
     if settings.TEST_SERVER_MODE:
         raise SkipTest("ServerMode will throw different errors")
     client = boto3.client("sns", region_name="any-region")
@@ -19,14 +19,14 @@ def test_use_invalid_region():
 
 @mock_sns
 @mock.patch.dict(os.environ, {"AWS_DEFAULT_REGION": "us-east-2"})
-def test_use_region_from_env():
+def test_use_region_from_env() -> None:  # type: ignore[misc]
     client = boto3.client("sns")
     assert client.list_platform_applications()["PlatformApplications"] == []
 
 
 @mock_sns
 @mock.patch.dict(os.environ, {"AWS_DEFAULT_REGION": "any-region"})
-def test_use_unknown_region_from_env():
+def test_use_unknown_region_from_env() -> None:  # type: ignore[misc]
     if settings.TEST_SERVER_MODE:
         raise SkipTest("Cannot set environemnt variables in ServerMode")
     client = boto3.client("sns")
@@ -38,7 +38,7 @@ def test_use_unknown_region_from_env():
 @mock_sns
 @mock.patch.dict(os.environ, {"AWS_DEFAULT_REGION": "any-region"})
 @mock.patch.dict(os.environ, {"MOTO_ALLOW_NONEXISTENT_REGION": "trUe"})
-def test_use_unknown_region_from_env_but_allow_it():
+def test_use_unknown_region_from_env_but_allow_it() -> None:  # type: ignore[misc]
     if settings.TEST_SERVER_MODE:
         raise SkipTest("Cannot set environemnt variables in ServerMode")
     client = boto3.client("sns")
@@ -47,7 +47,7 @@ def test_use_unknown_region_from_env_but_allow_it():
 
 @mock_dynamodb
 @mock.patch.dict(os.environ, {"MOTO_ALLOW_NONEXISTENT_REGION": "trUe"})
-def test_use_unknown_region_from_env_but_allow_it__dynamo():
+def test_use_unknown_region_from_env_but_allow_it__dynamo() -> None:  # type: ignore[misc]
     if settings.TEST_SERVER_MODE:
         raise SkipTest("Cannot set environemnt variables in ServerMode")
     dynamo_db = boto3.resource("dynamodb", region_name="test")
diff --git a/tests/test_core/test_moto_api.py b/tests/test_core/test_moto_api.py
index cbe9971a6..695801d02 100644
--- a/tests/test_core/test_moto_api.py
+++ b/tests/test_core/test_moto_api.py
@@ -18,7 +18,7 @@ data_url = f"{base_url}/moto-api/data.json"
 
 
 @mock_sqs
-def test_reset_api():
+def test_reset_api() -> None:
     conn = boto3.client("sqs", region_name="us-west-1")
     conn.create_queue(QueueName="queue1")
     assert len(conn.list_queues()["QueueUrls"]) == 1
@@ -30,7 +30,7 @@ def test_reset_api():
 
 
 @mock_sqs
-def test_data_api():
+def test_data_api() -> None:
     conn = boto3.client("sqs", region_name="us-west-1")
     conn.create_queue(QueueName="queue1")
 
@@ -41,7 +41,7 @@ def test_data_api():
 
 
 @mock_s3
-def test_overwriting_s3_object_still_returns_data():
+def test_overwriting_s3_object_still_returns_data() -> None:
     if settings.TEST_SERVER_MODE:
         raise SkipTest("No point in testing this behaves the same in ServerMode")
     s3 = boto3.client("s3", region_name="us-east-1")
@@ -53,7 +53,7 @@ def test_overwriting_s3_object_still_returns_data():
 
 
 @mock_autoscaling
-def test_creation_error__data_api_still_returns_thing():
+def test_creation_error__data_api_still_returns_thing() -> None:
     if settings.TEST_SERVER_MODE:
         raise SkipTest("No point in testing this behaves the same in ServerMode")
     # Timeline:
@@ -78,7 +78,7 @@ def test_creation_error__data_api_still_returns_thing():
 
     from moto.moto_api._internal.urls import response_instance
 
-    _, _, x = response_instance.model_data(None, None, None)
+    _, _, x = response_instance.model_data(None, "None", None)
 
     as_objects = json.loads(x)["autoscaling"]
     assert len(as_objects["FakeAutoScalingGroup"]) >= 1
@@ -87,7 +87,7 @@ def test_creation_error__data_api_still_returns_thing():
     assert "test_asg" in names
 
 
-def test_model_data_is_emptied_as_necessary():
+def test_model_data_is_emptied_as_necessary() -> None:
     if settings.TEST_SERVER_MODE:
         raise SkipTest("We're only interested in the decorator performance here")
 
@@ -97,24 +97,24 @@ def test_model_data_is_emptied_as_necessary():
     # No instances exist, because we have just reset it
     for classes_per_service in model_data.values():
         for _class in classes_per_service.values():
-            assert _class.instances == []
+            assert _class.instances == []  # type: ignore[attr-defined]
 
     with mock_sqs():
         # When just starting a mock, it is empty
         for classes_per_service in model_data.values():
             for _class in classes_per_service.values():
-                assert _class.instances == []
+                assert _class.instances == []  # type: ignore[attr-defined]
 
         # After creating a queue, some data will be present
         conn = boto3.client("sqs", region_name="us-west-1")
         conn.create_queue(QueueName="queue1")
 
-        assert len(model_data["sqs"]["Queue"].instances) == 1
+        assert len(model_data["sqs"]["Queue"].instances) == 1  # type: ignore[attr-defined]
 
     # But after the mock ends, it is empty again
     for classes_per_service in model_data.values():
         for _class in classes_per_service.values():
-            assert _class.instances == []
+            assert _class.instances == []  # type: ignore[attr-defined]
 
     # When we have multiple/nested mocks, the data should still be present after the first mock ends
     with mock_sqs():
@@ -122,24 +122,24 @@ def test_model_data_is_emptied_as_necessary():
         conn.create_queue(QueueName="queue1")
         with mock_s3():
             # The data should still be here - instances should not reset if another mock is still active
-            assert len(model_data["sqs"]["Queue"].instances) == 1
+            assert len(model_data["sqs"]["Queue"].instances) == 1  # type: ignore[attr-defined]
         # The data should still be here - the inner mock has exited, but the outer mock is still active
-        assert len(model_data["sqs"]["Queue"].instances) == 1
+        assert len(model_data["sqs"]["Queue"].instances) == 1  # type: ignore[attr-defined]
 
 
 @mock_sqs
 class TestModelDataResetForClassDecorator(TestCase):
-    def setUp(self):
+    def setUp(self) -> None:
         if settings.TEST_SERVER_MODE:
             raise SkipTest("We're only interested in the decorator performance here")
 
         # No data is present at the beginning
         for classes_per_service in model_data.values():
             for _class in classes_per_service.values():
-                assert _class.instances == []
+                assert _class.instances == []  # type: ignore[attr-defined]
 
         conn = boto3.client("sqs", region_name="us-west-1")
         conn.create_queue(QueueName="queue1")
 
-    def test_should_find_bucket(self):
-        assert len(model_data["sqs"]["Queue"].instances) == 1
+    def test_should_find_bucket(self) -> None:
+        assert len(model_data["sqs"]["Queue"].instances) == 1  # type: ignore[attr-defined]
diff --git a/tests/test_core/test_nested.py b/tests/test_core/test_nested.py
index f0acb9aee..7a79beea7 100644
--- a/tests/test_core/test_nested.py
+++ b/tests/test_core/test_nested.py
@@ -8,7 +8,7 @@ from tests import EXAMPLE_AMI_ID
 
 class TestNestedDecoratorsBoto3(unittest.TestCase):
     @mock_sqs
-    def setup_sqs_queue(self):
+    def setup_sqs_queue(self) -> None:
         conn = boto3.resource("sqs", region_name="us-east-1")
         queue = conn.create_queue(QueueName="some-queue")
 
@@ -18,7 +18,7 @@ class TestNestedDecoratorsBoto3(unittest.TestCase):
         assert queue.attributes["ApproximateNumberOfMessages"] == "1"
 
     @mock_ec2
-    def test_nested(self):
+    def test_nested(self) -> None:
         self.setup_sqs_queue()
 
         conn = boto3.client("ec2", region_name="us-west-2")
diff --git a/tests/test_core/test_responses.py b/tests/test_core/test_responses.py
index 173f0c49d..73f0cdf2f 100644
--- a/tests/test_core/test_responses.py
+++ b/tests/test_core/test_responses.py
@@ -1,9 +1,10 @@
 import datetime
 from collections import OrderedDict
 from gzip import compress as gzip_compress
+from typing import Any, Dict
 from unittest import SkipTest, mock
 
-from botocore.awsrequest import AWSPreparedRequest
+from botocore.awsrequest import AWSPreparedRequest, HTTPHeaders
 from freezegun import freeze_time
 
 from moto import settings
@@ -11,10 +12,10 @@ from moto.core.responses import AWSServiceSpec, BaseResponse, flatten_json_reque
 from moto.s3.responses import S3Response
 
 
-def test_flatten_json_request_body():
+def test_flatten_json_request_body() -> None:
     spec = AWSServiceSpec("data/emr/2009-03-31/service-2.json").input_spec("RunJobFlow")
 
-    body = {
+    body: Dict[str, Any] = {
         "Name": "cluster",
         "Instances": {
             "Ec2KeyName": "ec2key",
@@ -93,13 +94,15 @@ def test_flatten_json_request_body():
         assert props == body["Configurations"][idx]["Properties"]
 
 
-def test_parse_qs_unicode_decode_error():
+def test_parse_qs_unicode_decode_error() -> None:
     body = b'{"key": "%D0"}, "C": "#0 = :0"}'
-    request = AWSPreparedRequest("GET", "http://request", {"foo": "bar"}, body, False)
+    headers = HTTPHeaders()
+    headers["foo"] = "bar"
+    request = AWSPreparedRequest("GET", "http://request", headers, body, False)
     BaseResponse().setup_class(request, request.url, request.headers)
 
 
-def test_get_params():
+def test_get_params() -> None:
     subject = BaseResponse()
     subject.querystring = OrderedDict(
         [
@@ -150,7 +153,7 @@ def test_get_params():
     }
 
 
-def test_get_dict_list_params():
+def test_get_dict_list_params() -> None:
     subject = BaseResponse()
     subject.querystring = OrderedDict(
         [
@@ -168,7 +171,7 @@ def test_get_dict_list_params():
     assert result == {"VpcSecurityGroupId": ["sg-123", "sg-456", "sg-789"]}
 
 
-def test_response_environment_preserved_by_type():
+def test_response_environment_preserved_by_type() -> None:
     """Ensure Jinja environment is cached by response type."""
 
     class ResponseA(BaseResponse):
@@ -214,7 +217,7 @@ def test_response_environment_preserved_by_type():
     "moto.core.responses.settings.PRETTIFY_RESPONSES",
     new_callable=mock.PropertyMock(return_value=True),
 )
-def test_jinja_render_prettify(m_env_var):
+def test_jinja_render_prettify(m_env_var: Any) -> None:  # type: ignore[misc]
     if settings.TEST_SERVER_MODE:
         raise SkipTest(
             "It is not possible to set the environment variable in server mode"
@@ -228,12 +231,12 @@ def test_jinja_render_prettify(m_env_var):
     assert m_env_var
 
 
-def test_response_metadata():
+def test_response_metadata() -> None:
     # Setup
     frozen_time = datetime.datetime(
         2023, 5, 20, 10, 20, 30, tzinfo=datetime.timezone.utc
     )
-    request = AWSPreparedRequest("GET", "http://request", {}, None, False)
+    request = AWSPreparedRequest("GET", "http://request", HTTPHeaders(), None, False)
 
     # Execute
     with freeze_time(frozen_time):
@@ -246,12 +249,14 @@ def test_response_metadata():
         assert bc.response_headers["date"] == "Sat, 20 May 2023 10:20:30 GMT"
 
 
-def test_compression_gzip():
+def test_compression_gzip() -> None:
     body = '{"key": "%D0"}, "C": "#0 = :0"}'
+    headers = HTTPHeaders()
+    headers["Content-Encoding"] = "gzip"
     request = AWSPreparedRequest(
         "GET",
         url="http://request",
-        headers={"Content-Encoding": "gzip"},
+        headers=headers,
         body=_gzip_compress_body(body),
         stream_output=False,
     )
@@ -261,12 +266,14 @@ def test_compression_gzip():
     assert body == response.body
 
 
-def test_compression_gzip_in_s3():
+def test_compression_gzip_in_s3() -> None:
     body = b"some random data"
+    headers = HTTPHeaders()
+    headers["Content-Encoding"] = "gzip"
     request = AWSPreparedRequest(
         "GET",
         url="http://request",
-        headers={"Content-Encoding": "gzip"},
+        headers=headers,
         body=body,
         stream_output=False,
     )
@@ -276,6 +283,6 @@ def test_compression_gzip_in_s3():
     assert body == response.body.encode("utf-8")
 
 
-def _gzip_compress_body(body: str):
+def _gzip_compress_body(body: str) -> bytes:
     assert isinstance(body, str)
     return gzip_compress(data=body.encode("utf-8"))
diff --git a/tests/test_core/test_server.py b/tests/test_core/test_server.py
index 9f847e552..c67111afe 100644
--- a/tests/test_core/test_server.py
+++ b/tests/test_core/test_server.py
@@ -1,9 +1,10 @@
+from typing import Any
 from unittest.mock import patch
 
 from moto.server import DomainDispatcherApplication, create_backend_app, main
 
 
-def test_wrong_arguments():
+def test_wrong_arguments() -> None:
     try:
         main(["name", "test1", "test2", "test3"])
         assert False, (
@@ -15,7 +16,7 @@ def test_wrong_arguments():
 
 
 @patch("moto.server.run_simple")
-def test_right_arguments(run_simple):
+def test_right_arguments(run_simple: Any) -> None:  # type: ignore[misc]
     main(["s3"])
     func_call = run_simple.call_args[0]
     assert func_call[0] == "127.0.0.1"
@@ -23,14 +24,14 @@ def test_right_arguments(run_simple):
 
 
 @patch("moto.server.run_simple")
-def test_port_argument(run_simple):
+def test_port_argument(run_simple: Any) -> None:  # type: ignore[misc]
     main(["s3", "--port", "8080"])
     func_call = run_simple.call_args[0]
     assert func_call[0] == "127.0.0.1"
     assert func_call[1] == 8080
 
 
-def test_domain_dispatched():
+def test_domain_dispatched() -> None:
     dispatcher = DomainDispatcherApplication(create_backend_app)
     backend_app = dispatcher.get_application(
         {"HTTP_HOST": "email.us-east1.amazonaws.com"}
@@ -39,7 +40,7 @@ def test_domain_dispatched():
     assert keys[0] == "EmailResponse.dispatch"
 
 
-def test_domain_dispatched_with_service():
+def test_domain_dispatched_with_service() -> None:
     # If we pass a particular service, always return that.
     dispatcher = DomainDispatcherApplication(create_backend_app, service="s3")
     backend_app = dispatcher.get_application({"HTTP_HOST": "s3.us-east1.amazonaws.com"})
diff --git a/tests/test_core/test_settings.py b/tests/test_core/test_settings.py
index ce2d4b777..960daa9f0 100644
--- a/tests/test_core/test_settings.py
+++ b/tests/test_core/test_settings.py
@@ -10,17 +10,17 @@ Sanity checks for interpretation of the MOTO_ECS_NEW_ARN-variable
 """
 
 
-def test_default_is_true():
+def test_default_is_true() -> None:
     assert settings.ecs_new_arn_format() is True
 
 
 @pytest.mark.parametrize("value", ["TrUe", "true", "invalid", "0", "1"])
-def test_anything_but_false_is_true(value):
+def test_anything_but_false_is_true(value: str) -> None:
     with mock.patch.dict(os.environ, {"MOTO_ECS_NEW_ARN": value}):
         assert settings.ecs_new_arn_format() is True
 
 
 @pytest.mark.parametrize("value", ["False", "false", "faLse"])
-def test_only_false_is_false(value):
+def test_only_false_is_false(value: str) -> None:
     with mock.patch.dict(os.environ, {"MOTO_ECS_NEW_ARN": value}):
         assert settings.ecs_new_arn_format() is False
diff --git a/tests/test_core/test_socket.py b/tests/test_core/test_socket.py
index d68592fe5..97c341430 100644
--- a/tests/test_core/test_socket.py
+++ b/tests/test_core/test_socket.py
@@ -6,7 +6,7 @@ from moto import mock_dynamodb
 
 class TestSocketPair(unittest.TestCase):
     @mock_dynamodb
-    def test_socket_pair(self):
+    def test_socket_pair(self) -> None:
         a, b = socket.socketpair()
         self.assertIsNotNone(a)
         self.assertIsNotNone(b)
diff --git a/tests/test_core/test_url_base_regex.py b/tests/test_core/test_url_base_regex.py
index 80ab86646..b0bc2c632 100644
--- a/tests/test_core/test_url_base_regex.py
+++ b/tests/test_core/test_url_base_regex.py
@@ -5,7 +5,7 @@ import moto
 from moto import mock_s3
 
 service_names = [
-    (d[5:], "")
+    d[5:]
     for d in dir(moto)
     if d.startswith("mock_") and not d == "mock_xray_client" and not d == "mock_all"
 ]
@@ -16,8 +16,8 @@ class TestMockBucketStartingWithServiceName:
     https://github.com/getmoto/moto/issues/4099
     """
 
-    @pytest.mark.parametrize("service_name,decorator", service_names)
-    def test_bucketname_starting_with_service_name(self, service_name, decorator):
+    @pytest.mark.parametrize("service_name", service_names)
+    def test_bucketname_starting_with_service_name(self, service_name: str) -> None:
         decorator = getattr(moto, f"mock_{service_name}")
         with decorator():
             with mock_s3():
diff --git a/tests/test_core/test_url_mapping.py b/tests/test_core/test_url_mapping.py
index d0523584f..225b8d6f3 100644
--- a/tests/test_core/test_url_mapping.py
+++ b/tests/test_core/test_url_mapping.py
@@ -1,7 +1,7 @@
 from moto.core.utils import convert_regex_to_flask_path
 
 
-def test_flask_path_converting_simple():
+def test_flask_path_converting_simple() -> None:
     assert convert_regex_to_flask_path("/") == "/"
     assert convert_regex_to_flask_path("/$") == "/"
 
@@ -10,7 +10,7 @@ def test_flask_path_converting_simple():
     assert convert_regex_to_flask_path("/foo/bar/") == "/foo/bar/"
 
 
-def test_flask_path_converting_regex():
+def test_flask_path_converting_regex() -> None:
     assert (
         convert_regex_to_flask_path(r"/(?P<key_name>[a-zA-Z0-9\-_]+)")
         == r'/<regex("[a-zA-Z0-9\-_]+"):key_name>'
diff --git a/tests/test_core/test_utils.py b/tests/test_core/test_utils.py
index 916b37ec0..cc2e86749 100644
--- a/tests/test_core/test_utils.py
+++ b/tests/test_core/test_utils.py
@@ -19,7 +19,7 @@ from moto.core.utils import (
         ("ListMFADevices", "list_mfa_devices"),
     ],
 )
-def test_camelcase_to_underscores(_input, expected):
+def test_camelcase_to_underscores(_input: str, expected: str) -> None:
     assert camelcase_to_underscores(_input) == expected
 
 
@@ -27,7 +27,7 @@ def test_camelcase_to_underscores(_input, expected):
     "_input,expected",
     [("the_new_attribute", "theNewAttribute"), ("attribute", "attribute")],
 )
-def test_underscores_to_camelcase(_input, expected):
+def test_underscores_to_camelcase(_input: str, expected: str) -> None:
     assert underscores_to_camelcase(_input) == expected
 
 
@@ -35,7 +35,7 @@ def test_underscores_to_camelcase(_input, expected):
     "_input,expected",
     [("TheNewAttribute", "theNewAttribute"), ("Attribute", "attribute")],
 )
-def test_pascal_to_camelcase(_input, expected):
+def test_pascal_to_camelcase(_input: str, expected: str) -> None:
     assert pascal_to_camelcase(_input) == expected
 
 
@@ -43,10 +43,10 @@ def test_pascal_to_camelcase(_input, expected):
     "_input,expected",
     [("theNewAttribute", "TheNewAttribute"), ("attribute", "Attribute")],
 )
-def test_camelcase_to_pascal(_input, expected):
+def test_camelcase_to_pascal(_input: str, expected: str) -> None:
     assert camelcase_to_pascal(_input) == expected
 
 
 @freeze_time("2015-01-01 12:00:00")
-def test_unix_time():
+def test_unix_time() -> None:  # type: ignore[misc]
     assert unix_time() == 1420113600.0