Merge pull request #1098 from zauberzeug/timer_with_awaitable

Ensure timer runs awaitable

nicegui/functions/timer.py

@@ -1,10 +1,9 @@
 import asyncio
 import time
-from typing import Any, Callable, Optional
+from typing import Any, Awaitable, Callable, Optional
 
 from .. import background_tasks, globals
 from ..binding import BindableProperty
-from ..helpers import is_coroutine_function
 from ..slot import Slot
 
 
@@ -89,7 +88,7 @@ class Timer:
         try:
             assert self.callback is not None
             result = self.callback()
-            if is_coroutine_function(self.callback):
+            if isinstance(result, Awaitable):
                 await result
         except Exception as e:
             globals.handle_exception(e)

tests/screen.py

@@ -31,7 +31,7 @@ class Screen:
         self.ui_run_kwargs = {'port': PORT, 'show': False, 'reload': False}
 
     def start_server(self) -> None:
-        '''Start the webserver in a separate thread. This is the equivalent of `ui.run()` in a normal script.'''
+        """Start the webserver in a separate thread. This is the equivalent of `ui.run()` in a normal script."""
         self.server_thread = threading.Thread(target=ui.run, kwargs=self.ui_run_kwargs)
         self.server_thread.start()
 
@@ -45,17 +45,17 @@ class Screen:
             return False
 
     def stop_server(self) -> None:
-        '''Stop the webserver.'''
+        """Stop the webserver."""
         self.close()
         self.caplog.clear()
         globals.server.should_exit = True
         self.server_thread.join()
 
     def open(self, path: str, timeout: float = 3.0) -> None:
-        '''Try to open the page until the server is ready or we time out.
+        """Try to open the page until the server is ready or we time out.
 
         If the server is not yet running, start it.
-        '''
+        """
         if self.server_thread is None:
             self.start_server()
         deadline = time.time() + timeout
@@ -166,6 +166,7 @@ class Screen:
         self.selenium.get_screenshot_as_file(filename)
 
     def assert_py_logger(self, level: str, message: str) -> None:
+        """Assert that the Python logger has received a message with the given level and text."""
         try:
             assert self.caplog.records, 'Expected a log message'
             record = self.caplog.records[0]

tests/test_timer.py

@@ -1,3 +1,6 @@
+import asyncio
+import warnings
+
 import pytest
 
 from nicegui import ui
@@ -58,3 +61,15 @@ def test_setting_visibility(screen: Screen, once: bool):
     screen.open('/')
     screen.wait(0.5)
     screen.should_not_contain('Some Label')
+
+
+def test_awaiting_coroutine(screen: Screen):
+    warnings.simplefilter('error')
+
+    async def update_user():
+        await asyncio.sleep(0.1)
+
+    ui.timer(1, lambda: update_user())
+
+    screen.open('/')
+    screen.wait(1)