Add payer_offer() accessor method for invoice requests

Implements a public accessor method to retrieve the payer_offer field
from invoice requests. This completes the interface for accessing the
invreq_payer_offer experimental TLV field that was added in commit
61799bf.

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

Author: vincenzopalazzo

lightning/src/ln/offers_tests.rs

@@ -55,7 +55,7 @@ use crate::types::features::Bolt12InvoiceFeatures;
 use crate::ln::functional_test_utils::*;
 use crate::ln::msgs::{BaseMessageHandler, ChannelMessageHandler, Init, NodeAnnouncement, OnionMessage, OnionMessageHandler, RoutingMessageHandler, SocketAddress, UnsignedGossipMessage, UnsignedNodeAnnouncement};
 use crate::ln::outbound_payment::IDEMPOTENCY_TIMEOUT_TICKS;
-use crate::offers::invoice::Bolt12Invoice;
+use crate::offers::invoice::{self, Bolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
 use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields, InvoiceRequestVerifiedFromOffer};
 use crate::offers::nonce::Nonce;
@@ -2574,6 +2574,7 @@ fn pay_offer_and_add_contacts_info_blip42() {
 	// Now we check that there are the contact secret and the
 	// contact secret is the same that we inject by bob.
 	assert!(invoice_request.contact_secret().is_some());
+	assert!(invoice_request.payer_offer().is_some());
 	// TODO: we should check also if the contact secret is the same that we inject by bob.
 
 	let onion_message = alice.onion_messenger.next_onion_message_for_peer(bob_id).unwrap();

lightning/src/offers/invoice_request.rs

@@ -187,7 +187,7 @@ macro_rules! invoice_request_builder_methods { (
 		InvoiceRequestContentsWithoutPayerSigningPubkey {
 			payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 			features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
-			offer_from_hrn: None, invreq_contact_secret: None,
+			offer_from_hrn: None, invreq_contact_secret: None, invreq_payer_offer: None,
 			#[cfg(test)]
 			experimental_bar: None,
 		}
@@ -704,6 +704,7 @@ pub(super) struct InvoiceRequestContentsWithoutPayerSigningPubkey {
 	payer_note: Option<String>,
 	offer_from_hrn: Option<HumanReadableName>,
 	invreq_contact_secret: Option<Vec<u8>>,
+	invreq_payer_offer: Option<Vec<u8>>,
 	#[cfg(test)]
 	experimental_bar: Option<u64>,
 }
@@ -770,6 +771,11 @@ macro_rules! invoice_request_accessors { ($self: ident, $contents: expr) => {
 	pub fn contact_secret(&$self) -> Option<&[u8]> {
 		$contents.contact_secret()
 	}
+
+	/// Returns the payer offer if present in the invoice request.
+	pub fn payer_offer(&$self) -> Option<&[u8]> {
+		$contents.payer_offer()
+	}
 } }
 
 impl UnsignedInvoiceRequest {
@@ -1206,6 +1212,10 @@ impl InvoiceRequestContents {
 		self.inner.invreq_contact_secret.as_ref().map(|secret| secret.as_slice())
 	}
 
+	pub(super) fn payer_offer(&self) -> Option<&[u8]> {
+		self.inner.invreq_payer_offer.as_ref().map(|offer| offer.as_slice())
+	}
+
 	pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef<'_> {
 		let (payer, offer, mut invoice_request, experimental_offer, experimental_invoice_request) =
 			self.inner.as_tlv_stream();
@@ -1253,7 +1263,7 @@ impl InvoiceRequestContentsWithoutPayerSigningPubkey {
 
 		let experimental_invoice_request = ExperimentalInvoiceRequestTlvStreamRef {
 			invreq_contact_secret: self.invreq_contact_secret.as_ref(),
-			invreq_payer_offer: None,
+			invreq_payer_offer: self.invreq_payer_offer.as_ref(),
 			invreq_payer_bip_353_name: None,
 			#[cfg(test)]
 			experimental_bar: self.experimental_bar,
@@ -1494,7 +1504,7 @@ impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 			experimental_offer_tlv_stream,
 			ExperimentalInvoiceRequestTlvStream {
 				invreq_contact_secret,
-				invreq_payer_offer: _,
+				invreq_payer_offer,
 				invreq_payer_bip_353_name: _,
 				#[cfg(test)]
 				experimental_bar,
@@ -1540,6 +1550,7 @@ impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 				payer_note,
 				offer_from_hrn,
 				invreq_contact_secret,
+				invreq_payer_offer,
 				#[cfg(test)]
 				experimental_bar,
 			},