f add new test of outbound channels

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -8629,6 +8629,41 @@ mod tests {
 		get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, last_random_pk);
 	}
 
+	#[test]
+	fn test_outbound_chans_unlimited() {
+		// Test that we never refuse an outbound channel even if a peer is unfuned-channel-limited
+		let chanmon_cfgs = create_chanmon_cfgs(2);
+		let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+		let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+		let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+		// Note that create_network connects the nodes together for us
+
+		nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, 0, 42, None).unwrap();
+		let mut open_channel_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+
+		for _ in 0..super::MAX_UNFUNDED_CHANS_PER_PEER {
+			nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
+			get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id());
+			open_channel_msg.temporary_channel_id = nodes[0].keys_manager.get_secure_random_bytes();
+		}
+
+		// Once we have MAX_UNFUNDED_CHANS_PER_PEER unfunded channels, new inbound channels will be
+		// rejected.
+		nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
+		assert_eq!(get_err_msg!(nodes[1], nodes[0].node.get_our_node_id()).channel_id,
+			open_channel_msg.temporary_channel_id);
+
+		// but we can still open an outbound channel.
+		nodes[1].node.create_channel(nodes[0].node.get_our_node_id(), 100_000, 0, 42, None).unwrap();
+		get_event_msg!(nodes[1], MessageSendEvent::SendOpenChannel, nodes[0].node.get_our_node_id());
+
+		// but even with such an outbound channel, additional inbound channels will still fail.
+		nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel_msg);
+		assert_eq!(get_err_msg!(nodes[1], nodes[0].node.get_our_node_id()).channel_id,
+			open_channel_msg.temporary_channel_id);
+	}
+
 	#[test]
 	fn test_0conf_limiting() {
 		// Tests that we properly limit inbound channels when we have the manual-channel-acceptance