Add rng test coverage for BlindedPayInfo aggregation.

lightning/src/ln/blinded_payment_tests.rs

@@ -1050,3 +1050,100 @@ fn high_prop_fees() {
 	let expected_fee = pass_claimed_payment_along_route(args);
 	expect_payment_sent(&nodes[0], payment_preimage, Some(Some(expected_fee)), true, true);
 }
+
+#[cfg(feature = "std")]
+#[test]
+fn prop_fees_rng() {
+	do_prop_fees_rng(true);
+	do_prop_fees_rng(false);
+}
+
+#[cfg(feature = "std")]
+fn do_prop_fees_rng(send_min: bool) {
+	use std::hash::{BuildHasher, Hasher};
+	// Ensure the proportional fees are calculated correctly for `BlindedPayInfo`.
+	let chanmon_cfgs = create_chanmon_cfgs(5);
+	const PROP_LIMIT: u64 = 1_000_000;
+	let base_limit: u64 = if send_min { 1_000_000 } else { 15_000_000 };
+	const MIN_HTLC_LIMIT: u64 = 15_000_000;
+	let node_cfgs = create_node_cfgs(5, &chanmon_cfgs);
+
+	let mut node_1_cfg = test_default_channel_config();
+	node_1_cfg.channel_config.forwarding_fee_base_msat =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % base_limit) as u32;
+	node_1_cfg.channel_config.forwarding_fee_proportional_millionths =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % PROP_LIMIT) as u32;
+	if send_min {
+		node_1_cfg.channel_handshake_config.our_htlc_minimum_msat =
+			(std::collections::hash_map::RandomState::new().build_hasher().finish() % MIN_HTLC_LIMIT) as u64;
+	}
+
+	let mut node_2_cfg = test_default_channel_config();
+	node_2_cfg.channel_config.forwarding_fee_base_msat =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % base_limit) as u32;
+	node_2_cfg.channel_config.forwarding_fee_proportional_millionths =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % PROP_LIMIT) as u32;
+	if send_min {
+		node_2_cfg.channel_handshake_config.our_htlc_minimum_msat =
+			(std::collections::hash_map::RandomState::new().build_hasher().finish() % MIN_HTLC_LIMIT) as u64;
+	}
+
+	let mut node_3_cfg = test_default_channel_config();
+	node_3_cfg.channel_config.forwarding_fee_base_msat =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % base_limit) as u32;
+	node_3_cfg.channel_config.forwarding_fee_proportional_millionths =
+		(std::collections::hash_map::RandomState::new().build_hasher().finish() % PROP_LIMIT) as u32;
+	if send_min {
+		node_3_cfg.channel_handshake_config.our_htlc_minimum_msat =
+			(std::collections::hash_map::RandomState::new().build_hasher().finish() % MIN_HTLC_LIMIT) as u64;
+	}
+
+	let node_chanmgrs = create_node_chanmgrs(5, &node_cfgs, &[None, Some(node_1_cfg), Some(node_2_cfg), Some(node_3_cfg), None]);
+	let nodes = create_network(5, &node_cfgs, &node_chanmgrs);
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
+	let chan_1_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
+	let chan_2_3 = create_announced_chan_between_nodes_with_value(&nodes, 2, 3, 1_000_000, 0);
+	let chan_3_4 = create_announced_chan_between_nodes_with_value(&nodes, 3, 4, 1_000_000, 0);
+
+	let amt_msat = if send_min {
+		get_blinded_route_parameters(
+			42, PaymentSecret([0; 32]), chan_1_2.1.contents.htlc_minimum_msat,
+			chan_1_2.1.contents.htlc_maximum_msat,
+			nodes.iter().skip(1).map(|node| node.node.get_our_node_id()).collect(),
+			&[&chan_1_2.0.contents, &chan_2_3.0.contents, &chan_3_4.0.contents],
+			&chanmon_cfgs[4].keys_manager
+		)
+			.payment_params.payee.blinded_route_hints()[0].0.htlc_minimum_msat
+	} else { 100_000 };
+	let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[4], Some(amt_msat), None);
+
+	let mut route_params = get_blinded_route_parameters(amt_msat, payment_secret,
+		chan_1_2.1.contents.htlc_minimum_msat, chan_1_2.1.contents.htlc_maximum_msat,
+		nodes.iter().skip(1).map(|node| node.node.get_our_node_id()).collect(),
+		&[&chan_1_2.0.contents, &chan_2_3.0.contents, &chan_3_4.0.contents],
+		&chanmon_cfgs[4].keys_manager);
+	route_params.max_total_routing_fee_msat = None;
+
+	nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(), PaymentId(payment_hash.0), route_params.clone(), Retry::Attempts(0)).unwrap();
+	check_added_monitors(&nodes[0], 1);
+	let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+	assert_eq!(events.len(), 1);
+	let event = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
+	let expected_path = &[&nodes[1], &nodes[2], &nodes[3], &nodes[4]];
+
+	let args = PassAlongPathArgs::new(&nodes[0], expected_path, amt_msat, payment_hash, event)
+		.with_payment_secret(payment_secret)
+		.with_overpay_limit(if send_min { 40 } else { 3 });
+	let claimable_ev = do_pass_along_path(args);
+	let claim_amt = if let Some(crate::events::Event::PaymentClaimable { amount_msat, .. }) = claimable_ev {
+		amount_msat
+	} else { panic!() };
+	let overpayment_amt = claim_amt.checked_sub(amt_msat).unwrap();
+
+	nodes[4].node.claim_funds(payment_preimage);
+	let expected_route = &[&expected_path[..]];
+	let mut claim_args = ClaimAlongRouteArgs::new(&nodes[0], &expected_route[..], payment_preimage)
+		.allow_1_msat_fee_overpay();
+	let expected_fee = pass_claimed_payment_along_route(claim_args);
+	expect_payment_sent(&nodes[0], payment_preimage, Some(Some(expected_fee + overpayment_amt)), true, true);
+}