Functional tests for offers without blinded paths

lightning/src/ln/offers_tests.rs

@@ -211,3 +211,89 @@ fn creates_and_pays_for_refund_using_blinded_paths() {
 	claim_bolt12_payment(bob, &[alice]);
 	expect_recent_payment!(bob, RecentPaymentDetails::Fulfilled, payment_id);
 }
+
+/// Similar to `creates_and_pays_for_offer_using_blinded_paths` but for an offer without any blinded
+/// paths. Note that while the invoice is requested directly using the node's pubkey, the response
+/// and the payment still use blinded paths as required by the spec.
+#[test]
+fn creates_and_pays_for_offer_without_blinded_paths() {
+	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_unannounced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 1_000_000_000);
+
+	let alice = &nodes[0];
+	let alice_id = alice.node.get_our_node_id();
+	let bob = &nodes[1];
+	let bob_id = bob.node.get_our_node_id();
+
+	let offer = alice.node
+		.create_offer_builder("coffee".to_string())
+		.clear_paths()
+		.amount_msats(10_000_000)
+		.build().unwrap();
+	assert_eq!(offer.signing_pubkey(), alice_id);
+	assert!(offer.paths().is_empty());
+
+	let payment_id = PaymentId([1; 32]);
+	bob.node.pay_for_offer(&offer, None, None, None, payment_id, Retry::Attempts(0), None).unwrap();
+	expect_recent_payment!(bob, RecentPaymentDetails::AwaitingInvoice, payment_id);
+
+	let onion_message = bob.onion_messenger.next_onion_message_for_peer(alice_id).unwrap();
+	alice.onion_messenger.handle_onion_message(&bob_id, &onion_message);
+
+	let onion_message = alice.onion_messenger.next_onion_message_for_peer(bob_id).unwrap();
+	bob.onion_messenger.handle_onion_message(&alice_id, &onion_message);
+
+	let invoice = extract_invoice(bob, &onion_message);
+	route_bolt12_payment(bob, &[alice], &invoice);
+	expect_recent_payment!(bob, RecentPaymentDetails::Pending, payment_id);
+
+	claim_bolt12_payment(bob, &[alice]);
+	expect_recent_payment!(bob, RecentPaymentDetails::Fulfilled, payment_id);
+}
+
+/// Similar to `creates_and_pays_for_refund_using_blinded_paths` but for a refund without any
+/// blinded paths. Note that while the invoice is sent directly using the node's pubkey, the payment
+/// still uses blinded paths as required by the spec.
+#[test]
+fn creates_and_pays_for_refund_without_blinded_paths() {
+	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_unannounced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 1_000_000_000);
+
+	let alice = &nodes[0];
+	let alice_id = alice.node.get_our_node_id();
+	let bob = &nodes[1];
+	let bob_id = bob.node.get_our_node_id();
+
+	let absolute_expiry = Duration::from_secs(u64::MAX);
+	let payment_id = PaymentId([1; 32]);
+	let refund = bob.node
+		.create_refund_builder(
+			"refund".to_string(), 10_000_000, absolute_expiry, payment_id, Retry::Attempts(0), None
+		)
+		.unwrap()
+		.clear_paths()
+		.build().unwrap();
+	assert_eq!(refund.payer_id(), bob_id);
+	assert!(refund.paths().is_empty());
+	expect_recent_payment!(bob, RecentPaymentDetails::AwaitingInvoice, payment_id);
+
+	alice.node.request_refund_payment(&refund).unwrap();
+
+	let onion_message = alice.onion_messenger.next_onion_message_for_peer(bob_id).unwrap();
+	bob.onion_messenger.handle_onion_message(&alice_id, &onion_message);
+
+	let invoice = extract_invoice(bob, &onion_message);
+	route_bolt12_payment(bob, &[alice], &invoice);
+	expect_recent_payment!(bob, RecentPaymentDetails::Pending, payment_id);
+
+	claim_bolt12_payment(bob, &[alice]);
+	expect_recent_payment!(bob, RecentPaymentDetails::Fulfilled, payment_id);
+}

lightning/src/offers/offer.rs

@@ -339,6 +339,11 @@ impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 		self
 	}
 
+	pub(crate) fn clear_paths(mut self) -> Self {
+		self.offer.paths = None;
+		self
+	}
+
 	pub(super) fn build_unchecked(self) -> Offer {
 		self.build_without_checks()
 	}

lightning/src/offers/refund.rs

@@ -297,6 +297,11 @@ impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
 
 #[cfg(test)]
 impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
+	pub(crate) fn clear_paths(mut self) -> Self {
+		self.refund.paths = None;
+		self
+	}
+
 	fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 		self.refund.features = features;
 		self