tasks are not allowed to have arguments anymore

src/pydase/data_service/task_manager.py

@@ -3,10 +3,15 @@ from __future__ import annotations
 import asyncio
 import inspect
 import logging
-from typing import TYPE_CHECKING, Any, TypedDict
+from enum import Enum
+from typing import TYPE_CHECKING, Any
 
 from pydase.data_service.abstract_data_service import AbstractDataService
-from pydase.utils.helpers import get_class_and_instance_attributes
+from pydase.utils.helpers import (
+    function_has_arguments,
+    get_class_and_instance_attributes,
+    is_property_attribute,
+)
 
 if TYPE_CHECKING:
     from collections.abc import Callable
@@ -16,9 +21,12 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-class TaskDict(TypedDict):
+class TaskDefinitionError(Exception):
-    task: asyncio.Task[None]
+    pass
-    kwargs: dict[str, Any]
+
+
+class TaskStatus(Enum):
+    RUNNING = "running"
 
 
 class TaskManager:
@@ -78,7 +86,7 @@ class TaskManager:
     def __init__(self, service: DataService) -> None:
         self.service = service
 
-        self.tasks: dict[str, TaskDict] = {}
+        self.tasks: dict[str, asyncio.Task[None]] = {}
         """A dictionary to keep track of running tasks. The keys are the names of the
         tasks and the values are TaskDict instances which include the task itself and
         its kwargs.
@@ -91,12 +99,25 @@ class TaskManager:
         return asyncio.get_running_loop()
 
     def _set_start_and_stop_for_async_methods(self) -> None:
-        # inspect the methods of the class
+        for name in dir(self.service):
-        for name, method in inspect.getmembers(
+            # circumvents calling properties
-            self.service, predicate=inspect.iscoroutinefunction
+            if is_property_attribute(self.service, name):
-        ):
+                continue
+
+            method = getattr(self.service, name)
+            if inspect.iscoroutinefunction(method):
+                if function_has_arguments(method):
+                    raise TaskDefinitionError(
+                        "Asynchronous functions (tasks) should be defined without "
+                        f"arguments. The task '{method.__name__}' has at least one "
+                        "argument. Please remove the argument(s) from this function to "
+                        "use it."
+                    )
+
                 # create start and stop methods for each coroutine
-            setattr(self.service, f"start_{name}", self._make_start_task(name, method))
+                setattr(
+                    self.service, f"start_{name}", self._make_start_task(name, method)
+                )
                 setattr(self.service, f"stop_{name}", self._make_stop_task(name))
 
     def _initiate_task_startup(self) -> None:
@@ -137,7 +158,7 @@ class TaskManager:
             # cancel the task
             task = self.tasks.get(name, None)
             if task is not None:
-                self._loop.call_soon_threadsafe(task["task"].cancel)
+                self._loop.call_soon_threadsafe(task.cancel)
 
         return stop_task
 
@@ -156,7 +177,7 @@ class TaskManager:
             method (callable): The coroutine to be turned into an asyncio task.
         """
 
-        def start_task(*args: Any, **kwargs: Any) -> None:
+        def start_task() -> None:
             def task_done_callback(task: asyncio.Task[None], name: str) -> None:
                 """Handles tasks that have finished.
 
@@ -180,36 +201,16 @@ class TaskManager:
                     )
                     raise exception
 
-            async def task(*args: Any, **kwargs: Any) -> None:
+            async def task() -> None:
                 try:
-                    await method(*args, **kwargs)
+                    await method()
                 except asyncio.CancelledError:
                     logger.info("Task '%s' was cancelled", name)
 
             if not self.tasks.get(name):
-                # Get the signature of the coroutine method to start
-                sig = inspect.signature(method)
-
-                # Create a list of the parameter names from the method signature.
-                parameter_names = list(sig.parameters.keys())
-
-                # Extend the list of positional arguments with None values to match
-                # the length of the parameter names list. This is done to ensure
-                # that zip can pair each parameter name with a corresponding value.
-                args_padded = list(args) + [None] * (len(parameter_names) - len(args))
-
-                # Create a dictionary of keyword arguments by pairing the parameter
-                # names with the values in 'args_padded'. Then merge this dictionary
-                # with the 'kwargs' dictionary. If a parameter is specified in both
-                # 'args_padded' and 'kwargs', the value from 'kwargs' is used.
-                kwargs_updated = {
-                    **dict(zip(parameter_names, args_padded, strict=True)),
-                    **kwargs,
-                }
-
                 # creating the task and adding the task_done_callback which checks
                 # if an exception has occured during the task execution
-                task_object = self._loop.create_task(task(*args, **kwargs))
+                task_object = self._loop.create_task(task())
                 task_object.add_done_callback(
                     lambda task: task_done_callback(task, name)
                 )
@@ -217,13 +218,10 @@ class TaskManager:
                 # Store the task and its arguments in the '__tasks' dictionary. The
                 # key is the name of the method, and the value is a dictionary
                 # containing the task object and the updated keyword arguments.
-                self.tasks[name] = {
+                self.tasks[name] = task_object
-                    "task": task_object,
-                    "kwargs": kwargs_updated,
-                }
 
                 # emit the notification that the task was started
-                self.service._notify_changed(name, kwargs_updated)
+                self.service._notify_changed(name, TaskStatus.RUNNING)
             else:
                 logger.error("Task '%s' is already running!", name)