Add Payjoin example

..to run the example `cargo run --example ldk-node-with-payjoin-support`

Cargo.toml

@@ -102,3 +102,8 @@ panic = "abort"
 
 [profile.dev]
 panic = "abort"
+
+[[example]]
+name = "ldk-node-with-payjoin-support"
+path = "examples/ldk-node-with-payjoin-support.rs"
+

examples/ldk-node-with-payjoin-support.rs

@@ -0,0 +1,71 @@
+use ldk_node::bitcoin::Network;
+use ldk_node::{Builder, LogLevel};
+
+fn main() {
+	let mut builder = Builder::new();
+	builder.set_log_level(LogLevel::Gossip);
+	builder.set_network(Network::Testnet);
+	builder.set_esplora_server("https://blockstream.info/testnet/api".to_string());
+	builder.set_gossip_source_rgs(
+		"https://rapidsync.lightningdevkit.org/testnet/snapshot".to_string(),
+	);
+
+	// Payjoin directory is needed only if you are setting up Payjoin receiver,
+	// not required for Payjoin sender.
+	let payjoin_directory = "https://payjo.in".to_string();
+	// Payjoin relay is required for both Payjoin receiver and sender.
+	let payjoin_relay = "https://pj.bobspacebkk.com".to_string();
+
+	// Enable sending payjoin transactions
+	// builder.set_payjoin_sender_config(payjoin_relay.clone());
+	// ohttp keys refer to the Payjoin directory keys that are needed for the Payjoin receiver
+	// enrollement. If those keys are not provided the node will attempt to fetch them for you.
+	// let ohttp_keys = None;
+	// Enable receiving payjoin transactions
+	builder.set_payjoin_config(payjoin_directory, payjoin_relay);
+
+	let node = builder.build().unwrap();
+
+	node.start().unwrap();
+
+	// Receiving payjoin transaction
+	let payjoin_payment = node.payjoin_payment();
+	let amount_to_receive = bitcoin::Amount::from_sat(1000);
+	let payjoin_uri = payjoin_payment.receive(amount_to_receive).unwrap();
+	let payjoin_uri = payjoin_uri.to_string();
+
+	println!("Payjoin URI: {}", payjoin_uri);
+
+	//** Open a channel from incoming payjoin transactions ***//
+	// let payjoin_payment = node.payjoin_payment();
+	// let channel_amount_sats = bitcoin::Amount::from_sat(10000);
+	// use bitcoin::secp256k1::PublicKey;
+	// use lightning::ln::msgs::SocketAddress;
+	// let counterparty_node_id: PublicKey = unimplemented!();
+	// let counterparty_address: SocketAddress = unimplemented!();
+	// let payjoin_uri = match payjoin_payment.receive_with_channel_opening(channel_amount_sats, None, true,
+	// 	counterparty_node_id, counterparty_address,
+	// ).await {
+	// 	Ok(a) => a,
+	// 	Err(e) => {
+	// 		panic!("{}", e);
+	// 	},
+	// };
+	// let payjoin_uri = payjoin_uri.to_string();
+	// println!("Payjoin URI: {}", payjoin_uri);
+
+	//** Sending payjoin transaction **//
+	// let payjoin_uri = payjoin::Uri::try_from(payjoin_uri).unwrap();
+	// match payjoin_payment.send(payjoin_uri, None, None).await {
+	// 	Ok(Some(txid)) => {
+	//		dbg!("Sent transaction and got a response. Transaction completed")
+	// 	},
+	// 	Ok(None) => {
+	//		dbg!("Sent transaction and got no response. We will keep polling the response for the next 24hours")
+	// 	},
+	// 	Err(e) => {
+	// 		dbg!(e);
+	// 	}
+	// }
+	node.stop().unwrap();
+}

tests/integration_tests_payjoin.rs

@@ -40,3 +40,35 @@ fn send_receive_regular_payjoin_transaction() {
 	let node_b_balance = node_b_pj_sender.list_balances();
 	assert!(node_b_balance.total_onchain_balance_sats < premine_amount_sat - 80000);
 }
+
+#[test]
+fn send_payjoin_with_amount() {
+	let (bitcoind, electrsd) = setup_bitcoind_and_electrsd();
+	let (node_a_pj_receiver, node_b_pj_sender) = setup_two_payjoin_nodes(&electrsd, false);
+	let addr_b = node_b_pj_sender.onchain_payment().new_address().unwrap();
+	let addr_a = node_a_pj_receiver.onchain_payment().new_address().unwrap();
+	let premine_amount_sat = 100_000_00;
+	premine_and_distribute_funds(
+		&bitcoind.client,
+		&electrsd.client,
+		vec![addr_b, addr_a],
+		Amount::from_sat(premine_amount_sat),
+	);
+	node_a_pj_receiver.sync_wallets().unwrap();
+	node_b_pj_sender.sync_wallets().unwrap();
+	assert_eq!(node_b_pj_sender.list_balances().spendable_onchain_balance_sats, premine_amount_sat);
+	assert_eq!(node_a_pj_receiver.list_balances().spendable_onchain_balance_sats, 100_000_00);
+	assert_eq!(node_a_pj_receiver.next_event(), None);
+	let payjoin_payment = node_a_pj_receiver.payjoin_payment();
+	let payjoin_uri = payjoin_payment.receive(Amount::from_sat(100_000_000)).unwrap();
+	let payjoin_uri = payjoin_uri.to_string();
+	dbg!(&payjoin_uri);
+	let sender_payjoin_payment = node_b_pj_sender.payjoin_payment();
+	assert!(sender_payjoin_payment.send_with_amount(payjoin_uri, 80_000).is_ok());
+	let txid = expect_payjoin_tx_sent_successfully_event!(node_b_pj_sender);
+	wait_for_tx(&electrsd.client, txid);
+	generate_blocks_and_wait(&bitcoind.client, &electrsd.client, 6);
+	node_b_pj_sender.sync_wallets().unwrap();
+	let node_b_balance = node_b_pj_sender.list_balances();
+	assert!(node_b_balance.total_onchain_balance_sats < premine_amount_sat - 80000);
+}

tests/integration_tests_payjoin_with_channel_opening.rs

@@ -39,7 +39,8 @@ fn send_receive_payjoin_transaction_with_channel_opening() {
 			false,
 			node_b_pj_sender.node_id(),
 			node_b_listening_address,
-		).unwrap();
+		)
+		.unwrap();
 	let payjoin_uri = payjoin_uri.to_string();
 	let sender_payjoin_payment = node_b_pj_sender.payjoin_payment();
 	assert!(sender_payjoin_payment.send(payjoin_uri).is_ok());