Fix activity class type hinting when not instantiated (#104)

Author: adrien-f

temporalio/converter.py

@@ -732,16 +732,17 @@ def _type_hints_from_func(
     # the func. This mimics inspect logic inside Python.
     if (
         not inspect.isfunction(func)
-        and not isinstance(func, type)
         and not isinstance(func, _non_user_defined_callables)
         and not isinstance(func, types.MethodType)
     ):
-        # Callable instance
-        call_func = getattr(type(func), "__call__", None)
+        # Class type or Callable instance
+        tmp_func = func if isinstance(func, type) else type(func)
+        call_func = getattr(tmp_func, "__call__", None)
         if call_func is not None and not isinstance(
-            type(func), _non_user_defined_callables
+            tmp_func, _non_user_defined_callables
         ):
             func = call_func
+
     # We use inspect.signature for the parameter names and kinds, but we cannot
     # use it for annotations because those that are using deferred hinting (i.e.
     # from __future__ import annotations) only work with the eval_str parameter

tests/test_converter.py

@@ -172,5 +172,6 @@ def assert_hints(func: Any):
     assert_hints(some_hinted_func)
     assert_hints(some_hinted_func_async)
     assert_hints(MyCallableClass())
+    assert_hints(MyCallableClass)
     assert_hints(MyCallableClass.some_method)
     assert_hints(MyCallableClass().some_method)

tests/worker/test_workflow.py

@@ -2081,9 +2081,11 @@ async def __call__(self, to_add: MyDataClass) -> MyDataClass:
 class ActivityCallableClassWorkflow:
     @workflow.run
     async def run(self, to_add: MyDataClass) -> MyDataClass:
-        return await workflow.execute_activity_class(
+        result = await workflow.execute_activity_class(
             CallableClassActivity, to_add, start_to_close_timeout=timedelta(seconds=30)
         )
+        assert isinstance(result, MyDataClass)
+        return result
 
 
 async def test_workflow_activity_callable_class(client: Client):