Add a simple test of upgrading from LDK 0.1

One major hole in our test coverage historically has been tests
covering upgrades or downgrades across LDK versions. Luckily, these
aren't particularly hard to write as cargo lets us depend on
previous versions of the `lightning` crate directly, which we can
use in tests.

Here we add a simple initial test of upgrading from LDK 0.1 while
there's a pending payment to be claimed.

Author: TheBlueMatt

Cargo.toml

@@ -21,6 +21,7 @@ members = [
 
 exclude = [
     "lightning-transaction-sync",
+    "lightning-tests",
     "ext-functional-test-demo",
     "no-std-check",
     "msrv-no-dev-deps-check",

ci/ci-tests.sh

@@ -57,6 +57,12 @@ for DIR in "${WORKSPACE_MEMBERS[@]}"; do
 	cargo doc -p "$DIR" --document-private-items
 done
 
+echo -e "\n\nTesting upgrade from prior versions of LDK"
+pushd lightning-tests
+[ "$RUSTC_MINOR_VERSION" -lt 65 ] && cargo update -p regex --precise "1.9.6" --verbose
+cargo test
+popd
+
 echo -e "\n\nChecking and testing Block Sync Clients with features"
 
 cargo test -p lightning-block-sync --verbose --color always --features rest-client

lightning-tests/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "lightning-tests"
+version = "0.0.1"
+authors = ["Matt Corallo"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/lightningdevkit/rust-lightning/"
+description = "Tests for LDK crates"
+edition = "2021"
+
+[features]
+
+[dependencies]
+lightning-types = { path = "../lightning-types", features = ["_test_utils"] }
+lightning-invoice = { path = "../lightning-invoice", default-features = false }
+lightning-macros = { path = "../lightning-macros" }
+lightning = { path = "../lightning", features = ["_test_utils"] }
+lightning_0_1 = { package = "lightning", version = "0.1.1", features = ["_test_utils"] }
+
+bitcoin = { version = "0.32.2", default-features = false }
+
+[dev-dependencies]

lightning-tests/src/lib.rs

@@ -0,0 +1,5 @@
+#[cfg_attr(test, macro_use)]
+extern crate lightning;
+
+#[cfg(all(test, not(taproot)))]
+pub mod upgrade_downgrade_tests;

lightning-tests/src/upgrade_downgrade_tests.rs

@@ -0,0 +1,65 @@
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! Tests which test upgrading from previous versions of LDK or downgrading to previous versions of
+//! LDK.
+
+use lightning_0_1::get_monitor as get_monitor_0_1;
+use lightning_0_1::ln::functional_test_utils as lightning_0_1_utils;
+use lightning_0_1::util::ser::Writeable;
+
+use lightning::ln::functional_test_utils::*;
+
+use lightning_types::payment::PaymentPreimage;
+
+#[test]
+fn simple_upgrade() {
+	// Tests a simple case of upgrading from LDK 0.1 with a pending payment
+	let (node_a_ser, node_b_ser, mon_a_ser, mon_b_ser, preimage);
+	{
+		let chanmon_cfgs = lightning_0_1_utils::create_chanmon_cfgs(2);
+		let node_cfgs = lightning_0_1_utils::create_node_cfgs(2, &chanmon_cfgs);
+		let node_chanmgrs = lightning_0_1_utils::create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+		let nodes = lightning_0_1_utils::create_network(2, &node_cfgs, &node_chanmgrs);
+
+		let chan_id = lightning_0_1_utils::create_announced_chan_between_nodes(&nodes, 0, 1).2;
+
+		let payment_preimage =
+			lightning_0_1_utils::route_payment(&nodes[0], &[&nodes[1]], 1_000_000);
+		preimage = PaymentPreimage(payment_preimage.0 .0);
+
+		node_a_ser = nodes[0].node.encode();
+		node_b_ser = nodes[1].node.encode();
+		mon_a_ser = get_monitor_0_1!(nodes[0], chan_id).encode();
+		mon_b_ser = get_monitor_0_1!(nodes[1], chan_id).encode();
+	}
+
+	// Create a dummy node to reload over with the 0.1 state
+
+	let mut chanmon_cfgs = create_chanmon_cfgs(2);
+
+	// Our TestChannelSigner will fail as we're jumping ahead, so disable its state-based checks
+	chanmon_cfgs[0].keys_manager.disable_all_state_policy_checks = true;
+	chanmon_cfgs[1].keys_manager.disable_all_state_policy_checks = true;
+
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let (persister_a, persister_b, chain_mon_a, chain_mon_b);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let (node_a, node_b);
+	let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+	let config = test_default_channel_config();
+	let a_mons = &[&mon_a_ser[..]];
+	reload_node!(nodes[0], config.clone(), &node_a_ser, a_mons, persister_a, chain_mon_a, node_a);
+	reload_node!(nodes[1], config, &node_b_ser, &[&mon_b_ser], persister_b, chain_mon_b, node_b);
+
+	reconnect_nodes(ReconnectArgs::new(&nodes[0], &nodes[1]));
+
+	claim_payment(&nodes[0], &[&nodes[1]], preimage);
+}

lightning/src/ln/functional_test_utils.rs

@@ -1197,7 +1197,7 @@ pub fn _reload_node<'a, 'b, 'c>(node: &'a Node<'a, 'b, 'c>, default_config: User
 	node_deserialized
 }
 
-#[cfg(any(test, feature = "_externalize_tests"))]
+#[macro_export]
 macro_rules! reload_node {
 	($node: expr, $new_config: expr, $chanman_encoded: expr, $monitors_encoded: expr, $persister: ident, $new_chain_monitor: ident, $new_channelmanager: ident) => {
 		let chanman_encoded = $chanman_encoded;

lightning/src/onion_message/messenger.rs

@@ -1313,8 +1313,8 @@ where
 		}
 	}
 
-	#[cfg(any(test, feature = "_externalize_tests"))]
-	pub(crate) fn set_offers_handler(&mut self, offers_handler: OMH) {
+	#[cfg(any(test, feature = "_test_utils"))]
+	pub fn set_offers_handler(&mut self, offers_handler: OMH) {
 		self.offers_handler = offers_handler;
 	}