+ #[test]
+ fn avoids_recently_failed_paths() {
+ // Ensure that the router always avoids all of the `previously_failed_channels` channels by
+ // randomly inserting channels into it until we can't find a route anymore.
+ let (secp_ctx, network, _, _, logger) = build_graph();
+ let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
+ let network_graph = network.read_only();
+
+ let scorer = test_utils::TestScorer::with_penalty(0);
+ let mut payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
+ .with_max_path_count(1);
+ let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+ let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+ // We should be able to find a route initially, and then after we fail a few random
+ // channels eventually we won't be able to any longer.
+ assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).is_ok());
+ loop {
+ if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes) {
+ for chan in route.paths[0].iter() {
+ assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
+ }
+ let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
+ % route.paths[0].len();
+ payment_params.previously_failed_channels.push(route.paths[0][victim].short_channel_id);
+ } else { break; }
+ }
+ }
+