add mypy to [dev] deps and run it during the lint phase

dramatiq/actor.py

@@ -161,7 +161,7 @@ def send_with_options(
           Message: The enqueued message.
         """
         if isinstance(delay, timedelta):
-            delay = delay.total_seconds() * 1000
+            delay = int(delay.total_seconds() * 1000)
 
         message = self.message_with_options(args=args, kwargs=kwargs, **options)
         return self.broker.enqueue(message, delay=delay)

dramatiq/middleware/current_message.py

@@ -16,6 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import contextvars
+from typing import Optional
 
 from .middleware import Middleware
 
@@ -37,7 +38,7 @@ class CurrentMessage(Middleware):
     """
 
     _MESSAGE: contextvars.ContextVar[
-        dict
+        Optional[dict]
     ] = contextvars.ContextVar("_MESSAGE", default=None)
 
     @classmethod

setup.py

@@ -78,6 +78,7 @@ def rel(*xs):
     "flake8-bugbear",
     "flake8-quotes",
     "isort",
+    "mypy",
 
     # Misc
     "bumpversion",

tox.ini

@@ -34,6 +34,8 @@ deps =
   flake8
   flake8-bugbear
   flake8-quotes
+  mypy
 commands=
   flake8 {toxinidir}/dramatiq {toxinidir}/examples {toxinidir}/tests
   isort -c dramatiq
+  mypy dramatiq/ tests/