feat: 添加 _wait_for 辅助函数以优化测试中的等待逻辑，调整 FileWatcher 的防抖设置

pytests/config_test/test_file_watcher.py

@@ -107,13 +107,23 @@ async def test_unsubscribe_stops_dispatch(tmp_path: Path):
     assert calls == 0
 
 
+async def _wait_for(predicate, timeout: float = 5.0, interval: float = 0.05):
+    """轮询等待 predicate() 为真，避免依赖固定 sleep 导致跨平台不稳定。"""
+    deadline = asyncio.get_event_loop().time() + timeout
+    while asyncio.get_event_loop().time() < deadline:
+        if predicate():
+            return
+        await asyncio.sleep(interval)
+    raise TimeoutError(f"等待超时({timeout}s)")
+
+
 @pytest.mark.asyncio
 async def test_add_callback_while_watcher_running(tmp_path: Path):
     dirs = (tmp_path / "a_dir").resolve()
     dirs.mkdir(exist_ok=True)
     file = (dirs / "a.toml").resolve()
     file.touch()
-    watcher = FileWatcher(paths=[dirs])
+    watcher = FileWatcher(paths=[dirs], debounce_ms=200)
 
     calls = 0
 
@@ -124,15 +134,15 @@ async def test_add_callback_while_watcher_running(tmp_path: Path):
 
     uuid = watcher.subscribe(callback, paths=[file])
     await watcher.start()
-    with file.open("w") as f:
-        f.write("change")
-    await asyncio.sleep(0.5)
-    with file.open("r") as f:
-        content = f.read()
-    print(content)
-    assert calls == 1
-    watcher.unsubscribe(uuid)
-    with file.open("w") as f:
-        f.write("change2")
-    await asyncio.sleep(0.5)
-    assert calls == 1
+    try:
+        with file.open("w") as f:
+            f.write("change")
+        await _wait_for(lambda: calls >= 1)
+        assert calls == 1
+        watcher.unsubscribe(uuid)
+        with file.open("w") as f:
+            f.write("change2")
+        await asyncio.sleep(1.0)
+        assert calls == 1
+    finally:
+        await watcher.stop()