Refactor receive with supported_quantity

We now only build an offer with a supported_quantity when
the user set the quantity to Some.

To fix the tests I set the quantity to 1 while building the
offers.

Author: slanesuke

src/payment/bolt12.rs

@@ -255,27 +255,23 @@ impl Bolt12Payment {
 			Error::OfferCreationFailed
 		})?;
 
-		let user_set_qty = if let Some(qty) = quantity {
+		let mut offer =
+			offer_builder.amount_msats(amount_msat).description(description.to_string());
+
+		if let Some(qty) = quantity {
 			if qty == 0 {
 				return Err(Error::InvalidQuantity);
 			} else {
-				Quantity::Bounded(NonZeroU64::new(qty).unwrap())
-			}
-		} else {
-			Quantity::Unbounded
+				offer = offer.supported_quantity(Quantity::Bounded(NonZeroU64::new(qty).unwrap()))
+			};
 		};
 
-		let offer = offer_builder
-			.amount_msats(amount_msat)
-			.description(description.to_string())
-			.supported_quantity(user_set_qty)
-			.build()
-			.map_err(|e| {
-				log_error!(self.logger, "Failed to create offer: {:?}", e);
-				Error::OfferCreationFailed
-			})?;
+		let finalized_offer = offer.build().map_err(|e| {
+			log_error!(self.logger, "Failed to create offer: {:?}", e);
+			Error::OfferCreationFailed
+		})?;
 
-		Ok(offer)
+		Ok(finalized_offer)
 	}
 
 	/// Returns a payable offer that can be used to request and receive a payment for which the

tests/integration_tests_rust.rs

@@ -424,7 +424,7 @@ fn simple_bolt12_send_receive() {
 	std::thread::sleep(std::time::Duration::from_secs(1));
 
 	let expected_amount_msat = 100_000_000;
-	let offer = node_b.bolt12_payment().receive(expected_amount_msat, "asdf", None).unwrap();
+	let offer = node_b.bolt12_payment().receive(expected_amount_msat, "asdf", Some(1)).unwrap();
 	let expected_quantity = Some(1);
 	let expected_payer_note = Some("Test".to_string());
 	let payment_id = node_a
@@ -478,7 +478,7 @@ fn simple_bolt12_send_receive() {
 	let offer_amount_msat = 100_000_000;
 	let less_than_offer_amount = offer_amount_msat - 10_000;
 	let expected_amount_msat = offer_amount_msat + 10_000;
-	let offer = node_b.bolt12_payment().receive(offer_amount_msat, "asdf", None).unwrap();
+	let offer = node_b.bolt12_payment().receive(offer_amount_msat, "asdf", Some(1)).unwrap();
 	let expected_quantity = Some(1);
 	let expected_payer_note = Some("Test".to_string());
 	assert!(node_a