Replace get_err_msg macro with a function

The `get_err_msg!()` macro has no reason to be a macro so here we
move its logic to a function and leave the macro in place to avoid
touching every line of code in the tests.

This reduces the `--profile=test --lib` `Zpretty=expanded` code
size from 322,183 LoC to 321,985 LoC.

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -8469,7 +8469,7 @@ mod tests {
 		// A MAX_UNFUNDED_CHANS_PER_PEER + 1 channel will be summarily rejected
 		open_channel_msg.temporary_channel_id = nodes[0].keys_manager.get_secure_random_bytes();
 		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,
+		assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
 			open_channel_msg.temporary_channel_id);
 
 		// Further, because all of our channels with nodes[0] are inbound, and none of them funded,
@@ -8516,7 +8516,7 @@ mod tests {
 			open_channel_msg.temporary_channel_id = nodes[0].keys_manager.get_secure_random_bytes();
 		}
 		nodes[1].node.handle_open_channel(&last_random_pk, &open_channel_msg);
-		assert_eq!(get_err_msg!(nodes[1], last_random_pk).channel_id,
+		assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
 			open_channel_msg.temporary_channel_id);
 
 		// Of course, however, outbound channels are always allowed
@@ -8558,7 +8558,7 @@ mod tests {
 		// 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,
+		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.
@@ -8567,7 +8567,7 @@ mod tests {
 
 		// 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,
+		assert_eq!(get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id()).channel_id,
 			open_channel_msg.temporary_channel_id);
 	}
 
@@ -8623,7 +8623,7 @@ mod tests {
 			}
 			_ => panic!("Unexpected event"),
 		}
-		assert_eq!(get_err_msg!(nodes[1], last_random_pk).channel_id,
+		assert_eq!(get_err_msg(&nodes[1], &last_random_pk).channel_id,
 			open_channel_msg.temporary_channel_id);
 
 		// ...however if we accept the same channel 0conf it should work just fine.
@@ -8665,7 +8665,7 @@ mod tests {
 			_ => panic!("Unexpected event"),
 		}
 
-		let error_msg = get_err_msg!(nodes[1], nodes[0].node.get_our_node_id());
+		let error_msg = get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id());
 		nodes[0].node.handle_error(&nodes[1].node.get_our_node_id(), &error_msg);
 
 		let open_channel_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());

lightning/src/ln/functional_test_utils.rs

@@ -544,22 +544,17 @@ macro_rules! get_event_msg {
 }
 
 /// Get an error message from the pending events queue.
-#[macro_export]
-macro_rules! get_err_msg {
-	($node: expr, $node_id: expr) => {
-		{
-			let events = $node.node.get_and_clear_pending_msg_events();
-			assert_eq!(events.len(), 1);
-			match events[0] {
-				$crate::util::events::MessageSendEvent::HandleError {
-					action: $crate::ln::msgs::ErrorAction::SendErrorMessage { ref msg }, ref node_id
-				} => {
-					assert_eq!(*node_id, $node_id);
-					(*msg).clone()
-				},
-				_ => panic!("Unexpected event"),
-			}
-		}
+pub fn get_err_msg(node: &Node, recipient: &PublicKey) -> msgs::ErrorMessage {
+	let events = node.node.get_and_clear_pending_msg_events();
+	assert_eq!(events.len(), 1);
+	match events[0] {
+		MessageSendEvent::HandleError {
+			action: msgs::ErrorAction::SendErrorMessage { ref msg }, ref node_id
+		} => {
+			assert_eq!(node_id, recipient);
+			(*msg).clone()
+		},
+		_ => panic!("Unexpected event"),
 	}
 }
 

lightning/src/ln/priv_short_conf_tests.rs

@@ -278,7 +278,7 @@ fn test_scid_privacy_on_pub_channel() {
 	assert_eq!(open_channel.channel_flags & 1, 1); // The `announce_channel` bit is set.
 
 	nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_channel);
-	let err = get_err_msg!(nodes[1], nodes[0].node.get_our_node_id());
+	let err = get_err_msg(&nodes[1], &nodes[0].node.get_our_node_id());
 	assert_eq!(err.data, "SCID Alias/Privacy Channel Type cannot be set on a public channel");
 }
 
@@ -721,7 +721,7 @@ fn test_0conf_close_no_early_chan_update() {
 	nodes[0].node.force_close_all_channels_broadcasting_latest_txn();
 	check_added_monitors!(nodes[0], 1);
 	check_closed_event!(&nodes[0], 1, ClosureReason::HolderForceClosed);
-	let _ = get_err_msg!(nodes[0], nodes[1].node.get_our_node_id());
+	let _ = get_err_msg(&nodes[0], &nodes[1].node.get_our_node_id());
 }
 
 #[test]