Add quantity param to bolt12 send

Set the quantity by the user in the `send` method. We also
expose the quantity in required function calls.

Author: slanesuke

bindings/ldk_node.udl

@@ -120,7 +120,7 @@ interface Bolt11Payment {
 
 interface Bolt12Payment {
 	[Throws=NodeError]
-	PaymentId send([ByRef]Offer offer, string? payer_note);
+	PaymentId send([ByRef]Offer offer, u64? quantity, string? payer_note);
 	[Throws=NodeError]
 	PaymentId send_using_amount([ByRef]Offer offer, string? payer_note, u64 amount_msat);
 	[Throws=NodeError]

src/payment/bolt12.rs

@@ -48,13 +48,15 @@ impl Bolt12Payment {
 	///
 	/// If `payer_note` is `Some` it will be seen by the recipient and reflected back in the invoice
 	/// response.
-	pub fn send(&self, offer: &Offer, payer_note: Option<String>) -> Result<PaymentId, Error> {
+	///
+	/// If `quantity` is `Some` it represents the number of items requested.
+	pub fn send(
+		&self, offer: &Offer, quantity: Option<u64>, payer_note: Option<String>,
+	) -> Result<PaymentId, Error> {
 		let rt_lock = self.runtime.read().unwrap();
 		if rt_lock.is_none() {
 			return Err(Error::NotRunning);
 		}
-
-		let quantity = None;
 		let mut random_bytes = [0u8; 32];
 		rand::thread_rng().fill_bytes(&mut random_bytes);
 		let payment_id = PaymentId(random_bytes);
@@ -295,7 +297,7 @@ impl Bolt12Payment {
 			preimage: None,
 			secret: None,
 			payer_note: refund.payer_note().map(|note| UntrustedString(note.to_string())),
-			quantity,
+			quantity: refund.quantity(),
 		};
 
 		let payment = PaymentDetails::new(
@@ -349,7 +351,7 @@ impl Bolt12Payment {
 			preimage: None,
 			secret: None,
 			payer_note: refund.payer_note().map(|note| UntrustedString(note.to_string())),
-			quantity,
+			quantity: refund.quantity(),
 		};
 		let payment = PaymentDetails::new(
 			payment_id,

src/payment/unified_qr.rs

@@ -136,7 +136,7 @@ impl UnifiedQrPayment {
 			uri.clone().require_network(self.config.network).map_err(|_| Error::InvalidNetwork)?;
 
 		if let Some(offer) = uri_network_checked.extras.bolt12_offer {
-			match self.bolt12_payment.send(&offer, None) {
+			match self.bolt12_payment.send(&offer, None, None) {
 				Ok(payment_id) => return Ok(QrPaymentResult::Bolt12 { payment_id }),
 				Err(e) => log_error!(self.logger, "Failed to send BOLT12 offer: {:?}. This is part of a unified QR code payment. Falling back to the BOLT11 invoice.", e),
 			}

tests/integration_tests_rust.rs

@@ -425,7 +425,7 @@ fn simple_bolt12_send_receive() {
 
 	let expected_amount_msat = 100_000_000;
 	let offer = node_b.bolt12_payment().receive(expected_amount_msat, "asdf").unwrap();
-	let payment_id = node_a.bolt12_payment().send(&offer, None).unwrap();
+	let payment_id = node_a.bolt12_payment().send(&offer, None, None).unwrap();
 
 	expect_payment_successful_event!(node_a, Some(payment_id), None);
 	let node_a_payments = node_a.list_payments();
@@ -523,7 +523,7 @@ fn simple_bolt12_send_receive() {
 	let node_b_payments = node_b.list_payments_with_filter(|p| p.id == node_b_payment_id);
 	assert_eq!(node_b_payments.len(), 1);
 	match node_b_payments.first().unwrap().kind {
-		PaymentKind::Bolt12Refund { hash, preimage, secret: _ , ..} => {
+		PaymentKind::Bolt12Refund { hash, preimage, secret: _, .. } => {
 			assert!(hash.is_some());
 			assert!(preimage.is_some());
 			//TODO: We should eventually set and assert the secret sender-side, too, but the BOLT12