Introduce Blinded Payment Dummy Path test

Author: shaavan

lightning/src/ln/blinded_payment_tests.rs

@@ -196,6 +196,56 @@ fn do_one_hop_blinded_path(success: bool) {
 	}
 }
 
+#[test]
+fn one_hop_blinded_path_with_dummy_hops() {
+	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 nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+	let chan_upd = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0).0.contents;
+
+	let amt_msat = 5000;
+	let (payment_preimage, payment_hash, payment_secret) = get_payment_preimage_hash(&nodes[1], Some(amt_msat), None);
+	let payee_tlvs = ReceiveTlvs {
+		payment_secret,
+		payment_constraints: PaymentConstraints {
+			max_cltv_expiry: u32::max_value(),
+			htlc_minimum_msat: chan_upd.htlc_minimum_msat,
+		},
+		payment_context: PaymentContext::Bolt12Refund(Bolt12RefundContext {}),
+	};
+	let receive_auth_key = chanmon_cfgs[1].keys_manager.get_receive_auth_key();
+	let dummy_hops = 2;
+
+	let mut secp_ctx = Secp256k1::new();
+	let blinded_path = BlindedPaymentPath::new_with_dummy_hops(
+		&[], nodes[1].node.get_our_node_id(), dummy_hops, receive_auth_key,
+		payee_tlvs, u64::MAX, TEST_FINAL_CLTV as u16,
+		&chanmon_cfgs[1].keys_manager, &secp_ctx
+	).unwrap();
+
+	let route_params = RouteParameters::from_payment_params_and_value(
+		PaymentParameters::blinded(vec![blinded_path]),
+		amt_msat,
+	);
+	nodes[0].node.send_payment(payment_hash, RecipientOnionFields::spontaneous_empty(),
+	PaymentId(payment_hash.0), route_params, 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 ev = remove_first_msg_event_to_node(&nodes[1].node.get_our_node_id(), &mut events);
+
+	let path = &[&nodes[1]];
+	let args =
+		PassAlongPathArgs::new(&nodes[0], path, amt_msat, payment_hash, ev)
+		.with_dummy_override(dummy_hops)
+		.with_payment_secret(payment_secret);
+
+	do_pass_along_path(args);
+	claim_payment(&nodes[0], &[&nodes[1]], payment_preimage);
+}
+
 #[test]
 #[rustfmt::skip]
 fn mpp_to_one_hop_blinded_path() {