test: compatibility with reacton 2.0

See widgetti/reacton#42

Solara is already compatible with it, but the tests were not.

We might want to test this in CI, before releasing Solara 2.0

solara/tasks.py

@@ -104,6 +104,9 @@ def __init__(self, key: str):
         self._progress = ref(self._result.fields.progress)
         self._exception = ref(self._result.fields.exception)
         self._state_ = ref(self._result.fields._state)
+        # used for tests only
+        self._start_event = threading.Event()
+        self._start_event.set()
 
     @property
     def result(self) -> TaskResult[R]:
@@ -253,6 +256,8 @@ def is_current(self):
         return (self.current_task == asyncio.current_task()) and not running_task.cancelled()
 
     async def _async_run(self, call_event_loop: asyncio.AbstractEventLoop, future: asyncio.Future, args, kwargs) -> None:
+        self._start_event.wait()
+
         task_for_this_call = asyncio.current_task()
         assert task_for_this_call is not None
 
@@ -351,6 +356,7 @@ def is_current(self):
 
     def _run(self, _last_finished_event, previous_thread: Optional[threading.Thread], cancel_event, args, kwargs) -> None:
         # use_thread has this as default, which can make code run 10x slower
+        self._start_event.wait()
         intrusive_cancel = False
         wait_on_previous = False
         self._local.cancel_event = cancel_event

tests/unit/task_test.py

@@ -86,7 +86,11 @@ def collect():
 
     box, rc = solara.render(SquareButton(3, on_render=collect), handle_error=False)
     button = rc.find(v.Btn, children=["Run"]).widget
+    # a combination of .clear/.set is needed to force the rendering of all the states
+    # otherwise some states are not rendered
+    square._start_event.clear()  # type: ignore
     button.click()
+    square._start_event.set()  # type: ignore
     assert square._last_finished_event  # type: ignore
     square._last_finished_event.wait()  # type: ignore
     assert results == [
@@ -98,7 +102,9 @@ def collect():
     results.clear()
     rc.render(SquareButton(2, on_render=collect))
     button = rc.find(v.Btn, children=["Run"]).widget
+    square._start_event.clear()
     button.click()
+    square._start_event.set()
     square._last_finished_event.wait()  # type: ignore
     assert results == [
         # extra finished due to the rc.render call
@@ -152,7 +158,9 @@ def collect():
 
     box, rc = solara.render(SquareButtonAsync(3, on_render=collect), handle_error=False)
     button = rc.find(v.Btn, children=["Run"]).widget
+    square_async._start_event.clear()  # type: ignore
     button.click()
+    square_async._start_event.set()  # type: ignore
     assert square_async.current_future  # type: ignore
     await square_async.current_future  # type: ignore
     assert results == [
@@ -164,7 +172,9 @@ def collect():
     results.clear()
     rc.render(SquareButtonAsync(2, on_render=collect))
     button = rc.find(v.Btn, children=["Run"]).widget
+    square_async._start_event.clear()  # type: ignore
     button.click()
+    square_async._start_event.set()  # type: ignore
     await square_async.current_future  # type: ignore
     assert results == [
         # extra finished due to the rc.render call
@@ -195,8 +205,9 @@ def Test():
 
     box, rc = solara.render(Test(), handle_error=False)
     button = rc.find(v.Btn, children=["Run"])[0].widget
+    square._start_event.clear()  # type: ignore
     button.click()
-    assert square._last_finished_event  # type: ignore
+    square._start_event.set()  # type: ignore
     square._last_finished_event.wait()  # type: ignore
     assert (
         results2
@@ -214,7 +225,9 @@ def Test():
     results2.clear()
     results3.clear()
     button = rc.find(v.Btn, children=["Run"])[1].widget
+    square._start_event.clear()  # type: ignore
     button.click()
+    square._start_event.set()  # type: ignore
     assert square._last_finished_event  # type: ignore
     square._last_finished_event.wait()  # type: ignore
     assert (
@@ -244,7 +257,9 @@ def collect():
     button = rc.find(v.Btn, children=["Run"]).widget
     cancel_square = True
     try:
+        square._start_event.clear()  # type: ignore
         button.click()
+        square._start_event.set()  # type: ignore
         assert square._last_finished_event  # type: ignore
         square._last_finished_event.wait()  # type: ignore
         assert results == [
@@ -284,7 +299,9 @@ def collect():
     button = rc.find(v.Btn, children=["Run"]).widget
     cancel_square_async = True
     try:
+        square_async._start_event.clear()  # type: ignore
         button.click()
+        square_async._start_event.set()  # type: ignore
         assert square_async.current_future  # type: ignore
         try:
             await square_async.current_future  # type: ignore
@@ -337,7 +354,9 @@ def collect2():
         button2 = rc2.find(v.Btn, children=["Run"]).widget
 
     with context1:
+        something._start_event.clear()  # type: ignore
         button1.click()
+        something._start_event.set()  # type: ignore
         finished_event1 = something._last_finished_event  # type: ignore
         assert finished_event1
 
@@ -356,7 +375,9 @@ def collect2():
     assert results2 == [(TaskState.NOTCALLED, None)]
 
     with context2:
+        something._start_event.clear()  # type: ignore
         button2.click()
+        something._start_event.set()  # type: ignore
         finished_event2 = something._last_finished_event  # type: ignore
         assert finished_event2
     finished_event2.wait()