+fn test_fee_failures() {
+ // Tests that the fee required when forwarding remains consistent over time. This was
+ // previously broken, with forwarding fees floating based on the fee estimator at the time of
+ // forwarding.
+ //
+ // When this test was written, the default base fee floated based on the HTLC count.
+ // It is now fixed, so we simply set the fee to the expected value here.
+ let mut config = test_default_channel_config();
+ config.channel_options.forwarding_fee_base_msat = 196;
+
+ let chanmon_cfgs = create_chanmon_cfgs(3);
+ let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[Some(config), Some(config), Some(config)]);
+ let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+ let channels = [create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known()), create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known())];
+
+ // positive case
+ let (route, payment_hash_success, payment_preimage_success, payment_secret_success) = get_route_and_payment_hash!(nodes[0], nodes[2], 40_000);
+ nodes[0].node.send_payment(&route, payment_hash_success, &Some(payment_secret_success)).unwrap();
+ check_added_monitors!(nodes[0], 1);
+ pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2]]], 40_000, payment_hash_success, payment_secret_success);
+ claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], payment_preimage_success);
+
+ // If the hop gives fee_insufficient but enough fees were provided, then the previous hop
+ // malleated the payment before forwarding, taking funds when they shouldn't have.
+ let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);
+ let short_channel_id = channels[0].0.contents.short_channel_id;
+ run_onion_failure_test("fee_insufficient", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
+ msg.amount_msat -= 1;
+ }, || {}, true, Some(UPDATE|12), Some(NetworkUpdate::ChannelClosed { short_channel_id, is_permanent: true}), Some(short_channel_id));