Test failing pay_for_offer on an unsupported chain

Author: jkczyz

lightning/src/ln/offers_tests.rs

@@ -40,6 +40,7 @@
 //! Nodes without channels are disconnected and connected as needed to ensure that deterministic
 //! blinded paths are used.
 
+use bitcoin::network::constants::Network;
 use core::time::Duration;
 use crate::blinded_path::BlindedPath;
 use crate::events::{Event, MessageSendEventsProvider, PaymentPurpose};
@@ -732,6 +733,32 @@ fn fails_creating_refund_without_blinded_paths() {
 	assert!(nodes[0].node.list_recent_payments().is_empty());
 }
 
+/// Fails creating an invoice request when the offer contains an unsupported chain.
+#[test]
+fn fails_creating_invoice_request_for_unsupported_chain() {
+	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);
+
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 1_000_000_000);
+
+	let alice = &nodes[0];
+	let bob = &nodes[1];
+
+	let offer = alice.node
+		.create_offer_builder("coffee".to_string()).unwrap()
+		.clear_chains()
+		.chain(Network::Signet)
+		.build().unwrap();
+
+	let payment_id = PaymentId([1; 32]);
+	match bob.node.pay_for_offer(&offer, None, None, None, payment_id, Retry::Attempts(0), None) {
+		Ok(_) => panic!("Expected error"),
+		Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
+	}
+}
+
 /// Fails creating an invoice request when a blinded reply path cannot be created without exposing
 /// the node's id.
 #[test]

lightning/src/offers/offer.rs

@@ -390,6 +390,12 @@ macro_rules! offer_builder_test_methods { (
 		$return_value
 	}
 
+	#[cfg_attr(c_bindings, allow(dead_code))]
+	pub(crate) fn clear_chains($($self_mut)* $self: $self_type) -> $return_type {
+		$self.offer.chains = None;
+		$return_value
+	}
+
 	#[cfg_attr(c_bindings, allow(dead_code))]
 	pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 		$self.offer.paths = None;