Adding S16

tests/wrappers_tests/test_send_lightpush_and_edge.py

@@ -532,6 +532,85 @@ class TestS15LightpushRetryableErrorRecovery(StepsCommon):
                     assert_event_invariants(sender_collector, request_id)
 
 
+class TestS16LightpushPeerAppearsLater(StepsCommon):
+    """
+    S16 — No delivery peers at T0, lightpush peer appears later.
+    The edge sender starts fully isolated and send() is called before any
+    peer exists. A lightpush service node joins during the retry window,
+    and a later retry delivers the message.
+    Expected: send() returns Ok(RequestId), then eventually Propagated.
+    """
+
+    @pytest.mark.xfail(reason="lightpush peer discovery via staticnodes is broken, see https://github.com/logos-messaging/logos-delivery/issues/3847")
+    def test_s16_lightpush_peer_appears_later(self):
+        sender_collector = EventCollector()
+
+        common = {
+            "store": False,
+            "filter": False,
+            "discv5Discovery": False,
+            "numShardsInNetwork": 1,
+        }
+        service_config = build_node_config(relay=True, lightpush=True, **common)
+        service_result = WrapperManager.create_and_start(config=service_config)
+        assert service_result.is_ok(), f"Failed to start lightpush peer: {service_result.err()}"
+
+        with service_result.ok_value as service:
+            service_multiaddr = get_node_multiaddr(service)
+
+            stop_result = service.stop_node()
+            assert stop_result.is_ok(), f"Failed to stop lightpush peer: {stop_result.err()}"
+            delay(SERVICE_DOWN_SETTLE_S)
+
+            edge_config = build_node_config(
+                mode="Edge",
+                staticnodes=[service_multiaddr],
+                **common,
+            )
+            edge_result = WrapperManager.create_and_start(
+                config=edge_config,
+                event_cb=sender_collector.event_callback,
+            )
+            assert edge_result.is_ok(), f"Failed to start edge sender: {edge_result.err()}"
+
+            with edge_result.ok_value as edge_sender:
+                # send() is invoked while the sender is isolated; no peer exists yet.
+                msg = create_message_bindings(
+                    payload=to_base64("S16 lightpush peer appears later"),
+                    contentTopic="/test/1/s16-late-lightpush/proto",
+                )
+                send_result = edge_sender.send_message(message=msg)
+                assert send_result.is_ok(), f"send() failed: {send_result.err()}"
+                request_id = send_result.ok_value
+                assert request_id, "send() returned an empty RequestId"
+
+                delay(SERVICE_DOWN_SETTLE_S)
+
+                early_propagated = wait_for_propagated(sender_collector, request_id, timeout_s=0)
+                assert early_propagated is None, f"message_propagated arrived before any lightpush peer existed: {early_propagated}"
+
+                # The lightpush peer comes back during the retry window.
+                restart_result = service.start_node()
+                assert restart_result.is_ok(), f"Failed to restart lightpush peer: {restart_result.err()}"
+
+                propagated = wait_for_propagated(
+                    collector=sender_collector,
+                    request_id=request_id,
+                    timeout_s=RECOVERY_TIMEOUT_S,
+                )
+                assert propagated is not None, (
+                    f"No message_propagated within {RECOVERY_TIMEOUT_S}s "
+                    f"after the lightpush peer joined. "
+                    f"Collected events: {sender_collector.events}"
+                )
+                assert propagated["requestId"] == request_id
+
+                error = wait_for_error(sender_collector, request_id, timeout_s=0)
+                assert error is None, f"Unexpected message_error after recovery: {error}"
+
+                assert_event_invariants(sender_collector, request_id)
+
+
 class TestS26LightpushPeerChurn(StepsCommon):
     """
     S26: multiple lightpush peers, the selected one disappears,