fix: subscription re-init bug (#781)

* fix subscription re-initialization bug

* test for regression issue

* format

* Update cashu/mint/events/client.py

Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>

---------

Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>

cashu/mint/events/client.py

@@ -184,13 +184,11 @@ class LedgerEventClientManager:
         if len(self.subscriptions[kind]) >= self.max_subscriptions:
             raise ValueError("Max subscriptions reached")
 
-        for filter in filters:
-            if filter not in self.subscriptions:
-                self.subscriptions[kind][filter] = []
-            logger.debug(f"Adding subscription {subId} for filter {filter}")
-            self.subscriptions[kind][filter].append(subId)
+        for f in filters:
+            logger.debug(f"Adding subscription {subId} for filter {f}")
+            self.subscriptions[kind].setdefault(f, []).append(subId)
             # Initialize the subscription
-            asyncio.create_task(self._init_subscription(subId, filter, kind))
+            asyncio.create_task(self._init_subscription(subId, f, kind))
 
     def remove_subscription(self, subId: str) -> None:
         for kind, sub_filters in self.subscriptions.items():

tests/wallet/test_wallet_subscription.py

@@ -1,16 +1,16 @@
 import asyncio
+import threading
 
 import pytest
 import pytest_asyncio
 
 from cashu.core.base import Method, MintQuoteState, ProofState
-from cashu.core.json_rpc.base import JSONRPCNotficationParams
+from cashu.core.json_rpc.base import JSONRPCNotficationParams, JSONRPCSubscriptionKinds
 from cashu.core.nuts.nuts import WEBSOCKETS_NUT
 from cashu.core.settings import settings
 from cashu.wallet.wallet import Wallet
 from tests.conftest import SERVER_ENDPOINT
 from tests.helpers import (
-    is_fake,
     pay_if_regtest,
 )
 
@@ -27,7 +27,6 @@ async def wallet(mint):
 
 
 @pytest.mark.asyncio
-@pytest.mark.skipif(is_fake, reason="only regtest")
 async def test_wallet_subscription_mint(wallet: Wallet):
     if not wallet.mint_info.supports_nut(WEBSOCKETS_NUT):
         pytest.skip("No websocket support")
@@ -110,3 +109,68 @@ async def test_wallet_subscription_swap(wallet: Wallet):
     for msg in spent_stack:
         proof_state = ProofState.parse_obj(msg.payload)
         assert proof_state.spent
+
+
+@pytest.mark.asyncio
+async def test_wallet_subscription_multiple_listeners_receive_updates(wallet: Wallet):
+    """Regression test: ensure multiple subscriptions for the same quote receive updates.
+
+    We open two websocket subscriptions for the same mint quote and verify that
+    both listeners receive the initial (unpaid) state and the subsequent paid update.
+    """
+    if not wallet.mint_info.supports_nut(WEBSOCKETS_NUT):
+        pytest.skip("No websocket support")
+
+    if not wallet.mint_info.supports_websocket_mint_quote(
+        Method["bolt11"], wallet.unit
+    ):
+        pytest.skip("No websocket support for bolt11_mint_quote")
+
+    # Request a quote without auto-subscribing
+    mint_quote = await wallet.request_mint(123)
+
+    # Manually create a SubscriptionManager and subscribe twice to the same quote
+    from cashu.wallet.subscriptions import SubscriptionManager
+
+    subs = SubscriptionManager(wallet.url)
+    threading.Thread(target=subs.connect, name="SubscriptionManager", daemon=True).start()
+
+    stack1: list[JSONRPCNotficationParams] = []
+    stack2: list[JSONRPCNotficationParams] = []
+
+    def cb1(msg: JSONRPCNotficationParams):
+        stack1.append(msg)
+
+    def cb2(msg: JSONRPCNotficationParams):
+        stack2.append(msg)
+
+    subs.subscribe(
+        kind=JSONRPCSubscriptionKinds.BOLT11_MINT_QUOTE,
+        filters=[mint_quote.quote],
+        callback=cb1,
+    )
+    subs.subscribe(
+        kind=JSONRPCSubscriptionKinds.BOLT11_MINT_QUOTE,
+        filters=[mint_quote.quote],
+        callback=cb2,
+    )
+
+    # Allow time for the initial snapshot to arrive on both subscriptions
+    await asyncio.sleep(0.5)
+
+    assert len(stack1) >= 1 and len(stack2) >= 1
+    assert stack1[0].payload["state"] == MintQuoteState.unpaid.value
+    assert stack2[0].payload["state"] == MintQuoteState.unpaid.value
+
+    # Pay the invoice and wait for the paid update to be pushed to both listeners
+    await pay_if_regtest(mint_quote.request)
+
+    wait = (settings.fakewallet_delay_incoming_payment or 1) + 1
+    await asyncio.sleep(wait)
+
+    # Verify that both listeners received a paid update
+    assert any(m.payload["state"] == MintQuoteState.paid.value for m in stack1)
+    assert any(m.payload["state"] == MintQuoteState.paid.value for m in stack2)
+
+    # Cleanup the websocket
+    subs.close()