Add CBF integration tests and documentation

Author: febyeji

.github/workflows/rust.yml

@@ -84,7 +84,11 @@ jobs:
       - name: Test on Rust ${{ matrix.toolchain }}
         if: "matrix.platform != 'windows-latest'"
         run: |
-          RUSTFLAGS="--cfg no_download --cfg cycle_tests" cargo test
+          RUSTFLAGS="--cfg no_download --cfg cycle_tests" cargo test -- --skip cbf
+      - name: Test CBF on Rust ${{ matrix.toolchain }}
+        if: "matrix.platform != 'windows-latest'"
+        run: |
+          RUSTFLAGS="--cfg no_download --cfg cycle_tests" cargo test cbf -- --test-threads=1
       - name: Test with UniFFI support on Rust ${{ matrix.toolchain }}
         if: "matrix.platform != 'windows-latest' && matrix.build-uniffi"
         run: |

README.md

@@ -61,7 +61,7 @@ fn main() {
 LDK Node currently comes with a decidedly opinionated set of design choices:
 
 - On-chain data is handled by the integrated [BDK][bdk] wallet.
-- Chain data may currently be sourced from the Bitcoin Core RPC interface, or from an [Electrum][electrum] or [Esplora][esplora] server.
+- Chain data may currently be sourced from the Bitcoin Core RPC interface, from an [Electrum][electrum] or [Esplora][esplora] server, or via [compact block filters (BIP 157)][bip157].
 - Wallet and channel state may be persisted to an [SQLite][sqlite] database, to file system, or to a custom back-end to be implemented by the user.
 - Gossip data may be sourced via Lightning's peer-to-peer network or the [Rapid Gossip Sync](https://docs.rs/lightning-rapid-gossip-sync/*/lightning_rapid_gossip_sync/) protocol.
 - Entropy for the Lightning and on-chain wallets may be sourced from raw bytes or a [BIP39](https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki) mnemonic. In addition, LDK Node offers the means to generate and persist the entropy bytes to disk.
@@ -80,6 +80,7 @@ The Minimum Supported Rust Version (MSRV) is currently 1.85.0.
 [bdk]: https://bitcoindevkit.org/
 [electrum]: https://github.com/spesmilo/electrum-protocol
 [esplora]: https://github.com/Blockstream/esplora
+[bip157]: https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki
 [sqlite]: https://sqlite.org/
 [rust]: https://www.rust-lang.org/
 [swift]: https://www.swift.org/

tests/common/mod.rs

@@ -246,7 +246,16 @@ pub(crate) fn setup_bitcoind_and_electrsd() -> (BitcoinD, ElectrsD) {
 pub(crate) fn random_chain_source<'a>(
 	bitcoind: &'a BitcoinD, electrsd: &'a ElectrsD,
 ) -> TestChainSource<'a> {
-	let r = rand::random_range(0..3);
+	// Allow forcing a specific backend via LDK_TEST_CHAIN_SOURCE env var.
+	// Valid values: "esplora", "electrum", "bitcoind-rpc", "bitcoind-rest", "cbf"
+	let r = match std::env::var("LDK_TEST_CHAIN_SOURCE").ok().as_deref() {
+		Some("esplora") => 0,
+		Some("electrum") => 1,
+		Some("bitcoind-rpc") => 2,
+		Some("bitcoind-rest") => 3,
+		Some("cbf") => 4,
+		_ => rand::random_range(0..5),
+	};
 	match r {
 		0 => {
 			println!("Randomly setting up Esplora chain syncing...");
@@ -264,6 +273,10 @@ pub(crate) fn random_chain_source<'a>(
 			println!("Randomly setting up Bitcoind REST chain syncing...");
 			TestChainSource::BitcoindRestSync(bitcoind)
 		},
+		4 => {
+			println!("Randomly setting up CBF compact block filter syncing...");
+			TestChainSource::Cbf(bitcoind)
+		},
 		_ => unreachable!(),
 	}
 }