f Introduce force_close_channel method

Author: tnull

bindings/kotlin/ldk-node-jvm/lib/src/test/kotlin/org/lightningdevkit/ldknode/LibraryTest.kt

@@ -239,7 +239,7 @@ class LibraryTest {
         assert(node1.listPayments().size == 1)
         assert(node2.listPayments().size == 1)
 
-        node2.closeChannel(userChannelId, nodeId1, false)
+        node2.closeChannel(userChannelId, nodeId1)
 
         val channelClosedEvent1 = node1.waitNextEvent()
         println("Got event: $channelClosedEvent1")

bindings/ldk_node.udl

@@ -70,7 +70,9 @@ interface Node {
 	[Throws=NodeError]
 	UserChannelId connect_open_channel(PublicKey node_id, SocketAddress address, u64 channel_amount_sats, u64? push_to_counterparty_msat, ChannelConfig? channel_config, boolean announce_channel);
 	[Throws=NodeError]
-	void close_channel([ByRef]UserChannelId user_channel_id, PublicKey counterparty_node_id, boolean force);
+	void close_channel([ByRef]UserChannelId user_channel_id, PublicKey counterparty_node_id);
+	[Throws=NodeError]
+	void force_close_channel([ByRef]UserChannelId user_channel_id, PublicKey counterparty_node_id);
 	[Throws=NodeError]
 	void update_channel_config([ByRef]UserChannelId user_channel_id, PublicKey counterparty_node_id, ChannelConfig channel_config);
 	[Throws=NodeError]

bindings/python/src/ldk_node/test_ldk_node.py

@@ -198,7 +198,7 @@ def test_channel_full_cycle(self):
         print("EVENT:", payment_received_event_2)
         node_2.event_handled()
 
-        node_2.close_channel(channel_ready_event_2.user_channel_id, node_id_1, False)
+        node_2.close_channel(channel_ready_event_2.user_channel_id, node_id_1)
 
         channel_closed_event_1 = node_1.wait_next_event()
         assert isinstance(channel_closed_event_1, Event.CHANNEL_CLOSED)

src/lib.rs

@@ -1177,16 +1177,32 @@ impl Node {
 
 	/// Close a previously opened channel.
 	///
-	/// If `force` is set to `true`, we will force-close the channel, potentially broadcasting our
-	/// latest state. Note that in contrast to cooperative closure, force-closing will have the
-	/// channel funds time-locked, i.e., they will only be available after the counterparty had
-	/// time to contest our claim. Force-closing channels also more costly in terms of on-chain
-	/// fees. So cooperative closure should always be preferred (and tried first).
+	/// Will attempt to close a channel coopertively. If this fails, users might need to resort to
+	/// [`Node::force_close_channel`].
+	pub fn close_channel(
+		&self, user_channel_id: &UserChannelId, counterparty_node_id: PublicKey,
+	) -> Result<(), Error> {
+		self.close_channel_internal(user_channel_id, counterparty_node_id, false)
+	}
+
+	/// Force-close a previously opened channel.
+	///
+	/// Will force-close the channel, potentially broadcasting our latest state. Note that in
+	/// contrast to cooperative closure, force-closing will have the channel funds time-locked,
+	/// i.e., they will only be available after the counterparty had time to contest our claim.
+	/// Force-closing channels also more costly in terms of on-chain fees. So cooperative closure
+	/// should always be preferred (and tried first).
 	///
 	/// Broadcasting the closing transactions will be omitted for Anchor channels if we trust the
 	/// counterparty to broadcast for us (see [`AnchorChannelsConfig::trusted_peers_no_reserve`]
 	/// for more information).
-	pub fn close_channel(
+	pub fn force_close_channel(
+		&self, user_channel_id: &UserChannelId, counterparty_node_id: PublicKey,
+	) -> Result<(), Error> {
+		self.close_channel_internal(user_channel_id, counterparty_node_id, true)
+	}
+
+	fn close_channel_internal(
 		&self, user_channel_id: &UserChannelId, counterparty_node_id: PublicKey, force: bool,
 	) -> Result<(), Error> {
 		let open_channels =
@@ -1235,10 +1251,9 @@ impl Node {
 			if open_channels.len() == 1 {
 				self.peer_store.remove_peer(&counterparty_node_id)?;
 			}
-			Ok(())
-		} else {
-			Ok(())
 		}
+
+		Ok(())
 	}
 
 	/// Update the config for a previously opened channel.

tests/common/mod.rs

@@ -583,7 +583,7 @@ pub(crate) fn do_channel_full_cycle<E: ElectrumApi>(
 	assert_eq!(node_b.list_payments().len(), 5);
 
 	println!("\nB close_channel");
-	node_b.close_channel(&user_channel_id, node_a.node_id(), false).unwrap();
+	node_b.close_channel(&user_channel_id, node_a.node_id()).unwrap();
 	expect_event!(node_a, ChannelClosed);
 	expect_event!(node_b, ChannelClosed);
 

tests/integration_tests_cln.rs

@@ -111,7 +111,7 @@ fn test_cln() {
 	cln_client.pay(&ldk_invoice.to_string(), Default::default()).unwrap();
 	common::expect_event!(node, PaymentReceived);
 
-	node.close_channel(&user_channel_id, cln_node_id, false).unwrap();
+	node.close_channel(&user_channel_id, cln_node_id).unwrap();
 	common::expect_event!(node, ChannelClosed);
 	node.stop().unwrap();
 }