feat: fix inconsistent async handling bug for watcher.update() API (#406)

Author: Copilot

casbin/async_internal_enforcer.py

@@ -113,7 +113,10 @@ async def save_policy(self):
                 else:
                     update_for_save_policy(self.model)
             else:
-                self.watcher.update()
+                if inspect.iscoroutinefunction(self.watcher.update):
+                    await self.watcher.update()
+                else:
+                    self.watcher.update()
 
     async def _add_policy(self, sec, ptype, rule):
         """async adds a rule to the current policy."""
@@ -133,7 +136,10 @@ async def _add_policy(self, sec, ptype, rule):
                     else:
                         update_for_add_policy(sec, ptype, rule)
                 else:
-                    self.watcher.update()
+                    if inspect.iscoroutinefunction(self.watcher.update):
+                        await self.watcher.update()
+                    else:
+                        self.watcher.update()
 
         rule_added = self.model.add_policy(sec, ptype, rule)
 
@@ -161,7 +167,10 @@ async def _add_policies(self, sec, ptype, rules):
                     else:
                         update_for_add_policies(sec, ptype, rules)
                 else:
-                    self.watcher.update()
+                    if inspect.iscoroutinefunction(self.watcher.update):
+                        await self.watcher.update()
+                    else:
+                        self.watcher.update()
 
         rules_added = self.model.add_policies(sec, ptype, rules)
 
@@ -180,7 +189,10 @@ async def _update_policy(self, sec, ptype, old_rule, new_rule):
                 return False
 
             if self.watcher and self.auto_notify_watcher:
-                self.watcher.update()
+                if inspect.iscoroutinefunction(self.watcher.update):
+                    await self.watcher.update()
+                else:
+                    self.watcher.update()
 
         return rule_updated
 
@@ -197,7 +209,10 @@ async def _update_policies(self, sec, ptype, old_rules, new_rules):
                 return False
 
             if self.watcher and self.auto_notify_watcher:
-                self.watcher.update()
+                if inspect.iscoroutinefunction(self.watcher.update):
+                    await self.watcher.update()
+                else:
+                    self.watcher.update()
 
         return rules_updated
 
@@ -225,7 +240,10 @@ async def _update_filtered_policies(self, sec, ptype, new_rules, field_index, *f
         if sec == "g":
             self.build_role_links()
         if self.watcher and self.auto_notify_watcher:
-            self.watcher.update()
+            if inspect.iscoroutinefunction(self.watcher.update):
+                await self.watcher.update()
+            else:
+                self.watcher.update()
         return is_rule_changed
 
     async def _remove_policy(self, sec, ptype, rule):
@@ -247,7 +265,10 @@ async def _remove_policy(self, sec, ptype, rule):
                     else:
                         update_for_remove_policy(sec, ptype, rule)
                 else:
-                    self.watcher.update()
+                    if inspect.iscoroutinefunction(self.watcher.update):
+                        await self.watcher.update()
+                    else:
+                        self.watcher.update()
 
         return rule_removed
 
@@ -273,7 +294,10 @@ async def _remove_policies(self, sec, ptype, rules):
                     else:
                         update_for_remove_policies(sec, ptype, rules)
                 else:
-                    self.watcher.update()
+                    if inspect.iscoroutinefunction(self.watcher.update):
+                        await self.watcher.update()
+                    else:
+                        self.watcher.update()
 
         return rules_removed
 
@@ -296,7 +320,10 @@ async def _remove_filtered_policy(self, sec, ptype, field_index, *field_values):
                     else:
                         update_for_remove_filtered_policy(sec, ptype, field_index, *field_values)
                 else:
-                    self.watcher.update()
+                    if inspect.iscoroutinefunction(self.watcher.update):
+                        await self.watcher.update()
+                    else:
+                        self.watcher.update()
 
         return rule_removed
 
@@ -312,7 +339,10 @@ async def _remove_filtered_policy_returns_effects(self, sec, ptype, field_index,
                 return False
 
             if self.watcher and self.auto_notify_watcher:
-                self.watcher.update()
+                if inspect.iscoroutinefunction(self.watcher.update):
+                    await self.watcher.update()
+                else:
+                    self.watcher.update()
 
         return rule_removed
 

tests/test_watcher_ex.py

@@ -287,6 +287,24 @@ def test_auto_notify_disabled(self):
         self.assertEqual(w.notify_message, None)
 
 
+class AsyncMinimalWatcher:
+    """A minimal async watcher that only implements async update() method."""
+
+    def __init__(self):
+        self.update_count = 0
+
+    async def update(self):
+        """update the policy"""
+        self.update_count += 1
+        return True
+
+    async def close(self):
+        pass
+
+    async def set_update_callback(self, callback):
+        pass
+
+
 class TestAsyncWatcherEx(IsolatedAsyncioTestCase):
     def get_enforcer(self, model=None, adapter=None):
         return casbin.AsyncEnforcer(
@@ -365,3 +383,43 @@ async def test_auto_notify_disabled(self):
 
         await e.remove_policies(rules)
         self.assertEqual(w.notify_message, None)
+
+    async def test_async_minimal_watcher(self):
+        """Test that a watcher with only async update() method works properly."""
+        e = self.get_enforcer(
+            get_examples("basic_model.conf"),
+            get_examples("basic_policy.csv"),
+        )
+        await e.load_policy()
+
+        w = AsyncMinimalWatcher()
+        e.set_watcher(w)
+        e.enable_auto_notify_watcher(True)
+
+        # Test save_policy
+        await e.save_policy()
+        self.assertEqual(w.update_count, 1)
+
+        # Test add_policy - fallback to update()
+        await e.add_policy("admin", "data1", "read")
+        self.assertEqual(w.update_count, 2)
+
+        # Test remove_policy - fallback to update()
+        await e.remove_policy("admin", "data1", "read")
+        self.assertEqual(w.update_count, 3)
+
+        # Test remove_filtered_policy - fallback to update()
+        await e.remove_filtered_policy(1, "data1")
+        self.assertEqual(w.update_count, 4)
+
+        # Test add_policies - fallback to update()
+        rules = [
+            ["jack", "data4", "read"],
+            ["katy", "data4", "write"],
+        ]
+        await e.add_policies(rules)
+        self.assertEqual(w.update_count, 5)
+
+        # Test remove_policies - fallback to update()
+        await e.remove_policies(rules)
+        self.assertEqual(w.update_count, 6)