watchdog ignore closed_no_write

CHANGES.rst

@@ -1,5 +1,11 @@
 .. currentmodule:: werkzeug
 
+Unreleased
+
+-   The Watchdog reloader ignores file closed_no_write events. Bump the minimum
+    version of Watchdog to 5.0.3. :issue:`2945`
+
+
 Version 3.0.4
 -------------
 

requirements/dev.txt

@@ -191,7 +191,7 @@ virtualenv==20.26.3
     # via
     #   pre-commit
     #   tox
-watchdog==4.0.2
+watchdog==5.0.3
     # via
     #   -r tests.txt
     #   -r typing.txt

requirements/tests.txt

@@ -31,5 +31,5 @@ pytest-timeout==2.3.1
     # via -r tests.in
 pytest-xprocess==0.23.0
     # via -r tests.in
-watchdog==4.0.2
+watchdog==5.0.3
     # via -r tests.in

requirements/typing.txt

@@ -28,5 +28,5 @@ types-setuptools==73.0.0.20240822
     # via -r typing.in
 typing-extensions==4.12.2
     # via mypy
-watchdog==4.0.2
+watchdog==5.0.3
     # via -r typing.in

src/werkzeug/_reloader.py

@@ -312,6 +312,7 @@ def run_step(self) -> None:
 
 class WatchdogReloaderLoop(ReloaderLoop):
     def __init__(self, *args: t.Any, **kwargs: t.Any) -> None:
+        from watchdog.events import EVENT_TYPE_CLOSED_NO_WRITE
         from watchdog.events import EVENT_TYPE_OPENED
         from watchdog.events import FileModifiedEvent
         from watchdog.events import PatternMatchingEventHandler
@@ -322,7 +323,7 @@ def __init__(self, *args: t.Any, **kwargs: t.Any) -> None:
 
         class EventHandler(PatternMatchingEventHandler):
             def on_any_event(self, event: FileModifiedEvent):  # type: ignore
-                if event.event_type == EVENT_TYPE_OPENED:
+                if event.event_type in [EVENT_TYPE_OPENED, EVENT_TYPE_CLOSED_NO_WRITE]:
                     return
 
                 trigger_reload(event.src_path)

tests/test_serving.py

@@ -10,6 +10,7 @@
 from unittest.mock import patch
 
 import pytest
+from watchdog.events import EVENT_TYPE_CLOSED_NO_WRITE
 from watchdog.events import EVENT_TYPE_MODIFIED
 from watchdog.events import EVENT_TYPE_OPENED
 from watchdog.events import FileModifiedEvent
@@ -120,6 +121,29 @@ def test_reloader_sys_path(tmp_path, dev_server, reloader_type):
     assert client.request().status == 200
 
 
+@patch.object(WatchdogReloaderLoop, "trigger_reload")
+def test_watchdog_reloader_ignores_certain_events(mock_trigger_reload):
+    reloader = WatchdogReloaderLoop()
+    modified_event = FileModifiedEvent("")
+    modified_event.event_type = EVENT_TYPE_MODIFIED
+    reloader.event_handler.on_any_event(modified_event)
+    mock_trigger_reload.assert_called_once()
+
+    reloader.trigger_reload.reset_mock()
+
+    opened_event = FileModifiedEvent("")
+    opened_event.event_type = EVENT_TYPE_OPENED
+    reloader.event_handler.on_any_event(opened_event)
+    reloader.trigger_reload.assert_not_called()
+
+    reloader.trigger_reload.reset_mock()
+
+    closed_no_write_event = FileModifiedEvent("")
+    closed_no_write_event.event_type = EVENT_TYPE_CLOSED_NO_WRITE
+    reloader.event_handler.on_any_event(closed_no_write_event)
+    reloader.trigger_reload.assert_not_called()
+
+
 @patch.object(WatchdogReloaderLoop, "trigger_reload")
 def test_watchdog_reloader_ignores_opened(mock_trigger_reload):
     reloader = WatchdogReloaderLoop()