feat: Added tests for async watcher

I've added pytests to verify the functionality of async watcher callbacks.

Note: I used the existing pytest for synchronous calls as a reference for creating this async version.

tests/test_watcher_ex.py

@@ -14,7 +14,7 @@
 
 import casbin
 from tests.test_enforcer import get_examples, TestCaseBase
-
+from unittest import IsolatedAsyncioTestCase
 
 class SampleWatcher:
     def __init__(self):
@@ -113,6 +113,103 @@ def start_watch(self):
         pass
 
 
+class AsyncSampleWatcher():
+    def __init__(self):
+        self.callback = None
+        self.notify_message = None
+
+    async def close(self):
+        pass
+
+    async def set_update_callback(self, callback):
+        """
+        sets the callback function to be called when the policy is updated
+        :param callable callback: callback(event)
+            - event: event received from the rabbitmq
+        :return:
+        """
+        self.callback = callback
+
+    async def update(self, msg):
+        """
+        update the policy
+        """
+        self.notify_message = msg
+        return True
+
+    async def update_for_add_policy(self, section, ptype, *params):
+        """
+        update for add policy
+        :param section: section
+        :param ptype:   policy type
+        :param params:  other params
+        :return:    True if updated
+        """
+        message = "called add policy"
+        return await self.update(message)
+
+    async def update_for_remove_policy(self, section, ptype, *params):
+        """
+        update for remove policy
+        :param section: section
+        :param ptype:   policy type
+        :param params:  other params
+        :return:    True if updated
+        """
+        message = "called remove policy"
+        return await self.update(message)
+
+    async def update_for_remove_filtered_policy(self, section, ptype, field_index, *params):
+        """
+        update for remove filtered policy
+        :param section: section
+        :param ptype:   policy type
+        :param field_index: field index
+        :param params: other params
+        :return:
+        """
+        message = "called remove filtered policy"
+        return await self.update(message)
+
+    async def update_for_save_policy(self, model: casbin.Model):
+        """
+        update for save policy
+        :param model: casbin model
+        :return:
+        """
+        message = "called save policy"
+        return await self.update(message)
+
+    async def update_for_add_policies(self, section, ptype, *params):
+        """
+        update for add policies
+        :param section: section
+        :param ptype:   policy type
+        :param params:  other params
+        :return:
+        """
+        message = "called add policies"
+        return await self.update(message)
+
+    async def update_for_remove_policies(self, section, ptype, *params):
+        """
+        update for remove policies
+        :param section: section
+        :param ptype:   policy type
+        :param params:  other params
+        :return:
+        """
+        message = "called remove policies"
+        return await self.update(message)
+
+    async def start_watch(self):
+        """
+        starts the watch thread
+        :return:
+        """
+        pass
+
+
 class TestWatcherEx(TestCaseBase):
     def get_enforcer(self, model=None, adapter=None):
         return casbin.Enforcer(
@@ -187,3 +284,84 @@ def test_auto_notify_disabled(self):
 
         e.remove_policies(rules)
         self.assertEqual(w.notify_message, None)
+
+
+class TestAsyncWatcherEx(IsolatedAsyncioTestCase):
+    def get_enforcer(self, model=None, adapter=None):
+        return casbin.AsyncEnforcer(
+            model,
+            adapter,
+        )
+
+    async def test_auto_notify_enabled(self):
+        e = self.get_enforcer(
+            get_examples("basic_model.conf"),
+            get_examples("basic_policy.csv"),
+        )
+        await e.load_policy()
+
+        w = AsyncSampleWatcher()
+        e.set_watcher(w)
+        e.enable_auto_notify_watcher(True)
+
+        await e.save_policy()
+        self.assertEqual(w.notify_message, "called save policy")
+
+        await e.add_policy("admin", "data1", "read")
+        self.assertEqual(w.notify_message, "called add policy")
+
+        await e.remove_policy("admin", "data1", "read")
+        self.assertEqual(w.notify_message, "called remove policy")
+
+        await e.remove_filtered_policy(1, "data1")
+        self.assertEqual(w.notify_message, "called remove filtered policy")
+
+        rules = [
+            ["jack", "data4", "read"],
+            ["katy", "data4", "write"],
+            ["leyo", "data4", "read"],
+            ["ham", "data4", "write"],
+        ]
+        await e.add_policies(rules)
+        self.assertEqual(w.notify_message, "called add policies")
+
+        await e.remove_policies(rules)
+        self.assertEqual(w.notify_message, "called remove policies")
+
+
+    async def test_auto_notify_disabled(self):
+        e = self.get_enforcer(
+            get_examples("basic_model.conf"),
+            get_examples("basic_policy.csv"),
+        )
+        await e.load_policy()
+
+        w = SampleWatcher()
+        e.set_watcher(w)
+        e.enable_auto_notify_watcher(False)
+
+        await e.save_policy()
+        self.assertEqual(w.notify_message, "called save policy")
+
+        w.notify_message = None
+
+        await e.add_policy("admin", "data1", "read")
+        self.assertEqual(w.notify_message, None)
+
+        await e.remove_policy("admin", "data1", "read")
+        self.assertEqual(w.notify_message, None)
+
+        await e.remove_filtered_policy(1, "data1")
+        self.assertEqual(w.notify_message, None)
+
+        rules = [
+            ["jack", "data4", "read"],
+            ["katy", "data4", "write"],
+            ["leyo", "data4", "read"],
+            ["ham", "data4", "write"],
+        ]
+        await e.add_policies(rules)
+        self.assertEqual(w.notify_message, None)
+
+        await e.remove_policies(rules)
+        self.assertEqual(w.notify_message, None)