test serial renders too

Author: rmorshea

src/py/reactpy/reactpy/_option.py

@@ -68,6 +68,10 @@ def current(self) -> _O:
     def current(self, new: _O) -> None:
         self.set_current(new)
 
+    @current.deleter
+    def current(self) -> None:
+        self.unset()
+
     def subscribe(self, handler: Callable[[_O], None]) -> Callable[[_O], None]:
         """Register a callback that will be triggered when this option changes"""
         if not self.mutable:
@@ -123,7 +127,8 @@ def unset(self) -> None:
             msg = f"{self} cannot be modified after initial load"
             raise TypeError(msg)
         old = self.current
-        delattr(self, "_current")
+        if hasattr(self, "_current"):
+            delattr(self, "_current")
         if self.current != old:
             for sub_func in self._subscribers:
                 sub_func(self.current)

src/py/reactpy/tests/test_core/test_layout.py

@@ -2,14 +2,15 @@
 import gc
 import random
 import re
+from unittest.mock import patch
 from weakref import finalize
 from weakref import ref as weakref
 
 import pytest
 
 import reactpy
 from reactpy import html
-from reactpy.config import REACTPY_DEBUG_MODE
+from reactpy.config import REACTPY_DEBUG_MODE, REACTPY_FEATURE_CONCURRENT_RENDERING
 from reactpy.core.component import component
 from reactpy.core.hooks import use_effect, use_state
 from reactpy.core.layout import Layout
@@ -20,6 +21,7 @@
     assert_reactpy_did_log,
     capture_reactpy_logs,
 )
+from reactpy.testing.common import poll
 from reactpy.utils import Ref
 from tests.tooling import select
 from tests.tooling.aio import Event
@@ -29,6 +31,12 @@
 from tests.tooling.select import element_exists, find_element
 
 
+@pytest.fixture(autouse=True, params=[True, False])
+def concurrent_rendering(request):
+    with patch.object(REACTPY_FEATURE_CONCURRENT_RENDERING, "current", request.param):
+        yield request.param
+
+
 @pytest.fixture(autouse=True)
 def no_logged_errors():
     with capture_reactpy_logs() as logs:
@@ -832,17 +840,19 @@ def some_effect():
     async with reactpy.Layout(Root()) as layout:
         await layout.render()
 
-        assert effects == ["mount x"]
+        await poll(lambda: effects).until_equals(["mount x"])
 
         set_toggle.current()
         await layout.render()
 
-        assert effects == ["mount x", "unmount x", "mount y"]
+        await poll(lambda: effects).until_equals(["mount x", "unmount x", "mount y"])
 
         set_toggle.current()
         await layout.render()
 
-        assert effects == ["mount x", "unmount x", "mount y", "unmount y", "mount x"]
+        await poll(lambda: effects).until_equals(
+            ["mount x", "unmount x", "mount y", "unmount y", "mount x"]
+        )
 
 
 async def test_layout_does_not_copy_element_children_by_key():
@@ -1253,7 +1263,10 @@ def App():
         assert c["attributes"]["color"] == "blue"
 
 
-async def test_concurrent_renders():
+async def test_concurrent_renders(concurrent_rendering):
+    if not concurrent_rendering:
+        raise pytest.skip("Concurrent rendering not enabled")
+
     child_1_hook = HookCatcher()
     child_2_hook = HookCatcher()
     child_1_rendered = Event()