ln: add test helper for fee spike buffer test and use TxBuilder

Update test helper in preparation to test zero fee commitments, where
the local balance will differ from the previously hardcoded value.

Author: carlaKC

lightning/src/ln/htlc_reserve_unit_tests.rs

@@ -2,12 +2,11 @@
 
 use crate::events::{ClosureReason, Event, HTLCHandlingFailureType, PaymentPurpose};
 use crate::ln::chan_utils::{
-	self, commitment_tx_base_weight, second_stage_tx_fees_sat, CommitmentTransaction,
-	COMMITMENT_TX_WEIGHT_PER_HTLC,
+	self, commitment_tx_base_weight, second_stage_tx_fees_sat, COMMITMENT_TX_WEIGHT_PER_HTLC,
 };
 use crate::ln::channel::{
 	get_holder_selected_channel_reserve_satoshis, Channel, FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE,
-	MIN_AFFORDABLE_HTLC_COUNT,
+	MIN_AFFORDABLE_HTLC_COUNT, MIN_CHAN_DUST_LIMIT_SATOSHIS,
 };
 use crate::ln::channelmanager::{PaymentId, RAACommitmentOrder};
 use crate::ln::functional_test_utils::*;
@@ -16,6 +15,7 @@ use crate::ln::onion_utils::{self, AttributionData};
 use crate::ln::outbound_payment::RecipientOnionFields;
 use crate::routing::router::PaymentParameters;
 use crate::sign::ecdsa::EcdsaChannelSigner;
+use crate::sign::tx_builder::{SpecTxBuilder, TxBuilder};
 use crate::types::features::ChannelTypeFeatures;
 use crate::types::payment::PaymentPreimage;
 use crate::util::config::UserConfig;
@@ -772,16 +772,22 @@ pub fn test_basic_channel_reserve() {
 }
 
 #[xtest(feature = "_externalize_tests")]
-pub fn test_fee_spike_violation_fails_htlc() {
+fn test_fee_spike_violation_fails_htlc() {
+	do_test_fee_spike_buffer(None, true)
+}
+pub fn do_test_fee_spike_buffer(cfg: Option<UserConfig>, htlc_fails: bool) {
 	let chanmon_cfgs = create_chanmon_cfgs(2);
 	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[cfg.clone(), cfg]);
 	let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 
 	let node_a_id = nodes[0].node.get_our_node_id();
 	let node_b_id = nodes[1].node.get_our_node_id();
 
-	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+	let chan_amt_sat = 100000;
+	let push_amt_msat = 95000000;
+	let chan =
+		create_announced_chan_between_nodes_with_value(&nodes, 0, 1, chan_amt_sat, push_amt_msat);
 
 	let (mut route, payment_hash, _, payment_secret) =
 		get_route_and_payment_hash!(nodes[0], nodes[1], 3460000);
@@ -792,11 +798,12 @@ pub fn test_fee_spike_violation_fails_htlc() {
 
 	let cur_height = nodes[1].node.best_block.read().unwrap().height + 1;
 
+	let payment_amt_msat = 3460001;
 	let onion_keys = onion_utils::construct_onion_keys(&secp_ctx, &route.paths[0], &session_priv);
 	let recipient_onion_fields = RecipientOnionFields::secret_only(payment_secret);
 	let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(
 		&route.paths[0],
-		3460001,
+		payment_amt_msat,
 		&recipient_onion_fields,
 		cur_height,
 		&None,
@@ -858,16 +865,15 @@ pub fn test_fee_spike_violation_fails_htlc() {
 
 	// Build the remote commitment transaction so we can sign it, and then later use the
 	// signature for the commitment_signed message.
-	let local_chan_balance = 1313;
-
 	let accepted_htlc_info = chan_utils::HTLCOutputInCommitment {
 		offered: false,
-		amount_msat: 3460001,
+		amount_msat: payment_amt_msat,
 		cltv_expiry: htlc_cltv,
 		payment_hash,
 		transaction_output_index: Some(1),
 	};
 
+	let local_chan_balance_msat = chan_amt_sat * 1000 - push_amt_msat;
 	let commitment_number = INITIAL_COMMITMENT_NUMBER - 1;
 
 	let res = {
@@ -877,15 +883,17 @@ pub fn test_fee_spike_violation_fails_htlc() {
 		let channel = get_channel_ref!(nodes[0], nodes[1], per_peer_lock, peer_state_lock, chan.2);
 		let chan_signer = channel.as_funded().unwrap().get_signer();
 
-		let commitment_tx = CommitmentTransaction::new(
+		let (commitment_tx, _stats) = SpecTxBuilder {}.build_commitment_transaction(
+			false,
 			commitment_number,
 			&remote_point,
-			95000,
-			local_chan_balance,
-			feerate_per_kw,
-			vec![accepted_htlc_info],
-			&channel.funding().channel_transaction_parameters.as_counterparty_broadcastable(),
+			&channel.funding().channel_transaction_parameters,
 			&secp_ctx,
+			local_chan_balance_msat,
+			vec![accepted_htlc_info],
+			feerate_per_kw,
+			MIN_CHAN_DUST_LIMIT_SATOSHIS,
+			&nodes[0].logger,
 		);
 		let params = &channel.funding().channel_transaction_parameters;
 		chan_signer
@@ -918,28 +926,35 @@ pub fn test_fee_spike_violation_fails_htlc() {
 	};
 	nodes[1].node.handle_revoke_and_ack(node_a_id, &raa_msg);
 	expect_pending_htlcs_forwardable!(nodes[1]);
-	expect_htlc_handling_failed_destinations!(
-		nodes[1].node.get_and_clear_pending_events(),
-		&[HTLCHandlingFailureType::Receive { payment_hash }]
-	);
 
-	let events = nodes[1].node.get_and_clear_pending_msg_events();
-	assert_eq!(events.len(), 1);
-	// Make sure the HTLC failed in the way we expect.
-	match events[0] {
-		MessageSendEvent::UpdateHTLCs {
-			updates: msgs::CommitmentUpdate { ref update_fail_htlcs, .. },
-			..
-		} => {
-			assert_eq!(update_fail_htlcs.len(), 1);
-			update_fail_htlcs[0].clone()
-		},
-		_ => panic!("Unexpected event"),
-	};
-	nodes[1].logger.assert_log("lightning::ln::channel",
+	if htlc_fails {
+		expect_htlc_handling_failed_destinations!(
+			nodes[1].node.get_and_clear_pending_events(),
+			&[HTLCHandlingFailureType::Receive { payment_hash }]
+		);
+
+		let events = nodes[1].node.get_and_clear_pending_msg_events();
+		assert_eq!(events.len(), 1);
+
+		// Make sure the HTLC failed in the way we expect.
+		match events[0] {
+			MessageSendEvent::UpdateHTLCs {
+				updates: msgs::CommitmentUpdate { ref update_fail_htlcs, .. },
+				..
+			} => {
+				assert_eq!(update_fail_htlcs.len(), 1);
+				update_fail_htlcs[0].clone()
+			},
+			_ => panic!("Unexpected event"),
+		};
+		nodes[1].logger.assert_log("lightning::ln::channel",
 		format!("Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", raa_msg.channel_id), 1);
 
-	check_added_monitors(&nodes[1], 3);
+		check_added_monitors(&nodes[1], 3);
+	} else {
+		expect_payment_claimable!(nodes[1], payment_hash, payment_secret, payment_amt_msat);
+		check_added_monitors(&nodes[1], 2);
+	}
 }
 
 #[xtest(feature = "_externalize_tests")]