Test PaymentRetryHandler in BackgroundProcessor

Proof of concept showing PaymentRetryHandler can be used with an
Arc<ChannelManager> passed to BackgroundProcessor. Likely do not need to
merge this commit.

lightning-background-processor/Cargo.toml

@@ -12,6 +12,7 @@ edition = "2018"
 [dependencies]
 bitcoin = "0.27"
 lightning = { version = "0.0.99", path = "../lightning", features = ["allow_wallclock_use"] }
+lightning-invoice = { version = "0.7.0", path = "../lightning-invoice" }
 lightning-persister = { version = "0.0.99", path = "../lightning-persister" }
 
 [dev-dependencies]

lightning-background-processor/src/lib.rs

@@ -119,7 +119,7 @@ impl BackgroundProcessor {
 		Descriptor: 'static + SocketDescriptor + Send + Sync,
 		CMH: 'static + Deref + Send + Sync,
 		RMH: 'static + Deref + Send + Sync,
-		EH: 'static + EventHandler + Send + Sync,
+		EH: 'static + EventHandler + Send,
 		CMP: 'static + Send + ChannelManagerPersister<Signer, CW, T, K, F, L>,
 		M: 'static + Deref<Target = ChainMonitor<Signer, CF, T, F, L, P>> + Send + Sync,
 		CM: 'static + Deref<Target = ChannelManager<Signer, CW, T, K, F, L>> + Send + Sync,
@@ -248,10 +248,13 @@ mod tests {
 	use lightning::ln::features::InitFeatures;
 	use lightning::ln::msgs::{ChannelMessageHandler, Init};
 	use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
+	use lightning::routing::network_graph::NetworkGraph;
 	use lightning::util::config::UserConfig;
 	use lightning::util::events::{Event, MessageSendEventsProvider, MessageSendEvent};
 	use lightning::util::ser::Writeable;
 	use lightning::util::test_utils;
+	use lightning_invoice::payment::InvoicePayer;
+	use lightning_invoice::utils::DefaultRouter;
 	use lightning_persister::FilesystemPersister;
 	use std::fs;
 	use std::path::PathBuf;
@@ -552,4 +555,19 @@ mod tests {
 
 		assert!(bg_processor.stop().is_ok());
 	}
+
+	#[test]
+	fn test_invoice_payer() {
+		let nodes = create_nodes(2, "test_invoice_payer".to_string());
+
+		// Initiate the background processors to watch each node.
+		let data_dir = nodes[0].persister.get_data_dir();
+		let persister = move |node: &ChannelManager<InMemorySigner, Arc<ChainMonitor>, Arc<test_utils::TestBroadcaster>, Arc<KeysManager>, Arc<test_utils::TestFeeEstimator>, Arc<test_utils::TestLogger>>| FilesystemPersister::persist_manager(data_dir.clone(), node);
+		let router = DefaultRouter::new(Arc::clone(&nodes[0].logger));
+		let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
+		let event_handler = |_: &_| {};
+		let (_, event_handler) = InvoicePayer::new(Arc::clone(&nodes[0].node), router, network_graph, Arc::clone(&nodes[0].logger), event_handler);
+		let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].peer_manager.clone(), nodes[0].logger.clone());
+		assert!(bg_processor.stop().is_ok());
+	}
 }