fix(auth): allow listeners to unsubscribe during notification

src/auth/src/supabase_auth/_async/gotrue_client.py

@@ -1139,7 +1139,7 @@ def _notify_all_subscribers(
         event: AuthChangeEvent,
         session: Optional[Session],
     ) -> None:
-        for subscription in self._state_change_emitters.values():
+        for subscription in list(self._state_change_emitters.values()):
             subscription.callback(event, session)
 
     def _get_valid_session(

src/auth/src/supabase_auth/_sync/gotrue_client.py

@@ -1133,7 +1133,7 @@ def _notify_all_subscribers(
         event: AuthChangeEvent,
         session: Optional[Session],
     ) -> None:
-        for subscription in self._state_change_emitters.values():
+        for subscription in list(self._state_change_emitters.values()):
             subscription.callback(event, session)
 
     def _get_valid_session(

src/auth/tests/_async/test_subscriptions.py

@@ -0,0 +1,31 @@
+from typing import Optional
+
+from supabase_auth.types import AuthChangeEvent, Session
+
+from .clients import auth_client
+
+
+async def test_auth_state_change_callback_can_unsubscribe_during_notification() -> None:
+    client = auth_client()
+    received: list[tuple[str, AuthChangeEvent]] = []
+
+    def unsubscribe_on_event(
+        event: AuthChangeEvent, session: Optional[Session]
+    ) -> None:
+        received.append(("once", event))
+        subscription.unsubscribe()
+
+    subscription = client.on_auth_state_change(unsubscribe_on_event)
+    client.on_auth_state_change(
+        lambda event, session: received.append(("always", event))
+    )
+
+    await client.sign_out()
+    assert received == [("once", "SIGNED_OUT"), ("always", "SIGNED_OUT")]
+
+    await client.sign_out()
+    assert received == [
+        ("once", "SIGNED_OUT"),
+        ("always", "SIGNED_OUT"),
+        ("always", "SIGNED_OUT"),
+    ]

src/auth/tests/_sync/test_subscriptions.py

@@ -0,0 +1,31 @@
+from typing import Optional
+
+from supabase_auth.types import AuthChangeEvent, Session
+
+from .clients import auth_client
+
+
+def test_auth_state_change_callback_can_unsubscribe_during_notification() -> None:
+    client = auth_client()
+    received: list[tuple[str, AuthChangeEvent]] = []
+
+    def unsubscribe_on_event(
+        event: AuthChangeEvent, session: Optional[Session]
+    ) -> None:
+        received.append(("once", event))
+        subscription.unsubscribe()
+
+    subscription = client.on_auth_state_change(unsubscribe_on_event)
+    client.on_auth_state_change(
+        lambda event, session: received.append(("always", event))
+    )
+
+    client.sign_out()
+    assert received == [("once", "SIGNED_OUT"), ("always", "SIGNED_OUT")]
+
+    client.sign_out()
+    assert received == [
+        ("once", "SIGNED_OUT"),
+        ("always", "SIGNED_OUT"),
+        ("always", "SIGNED_OUT"),
+    ]