Address clippy lints in lightning test code

In a coming commit we'll enable `clippy` linting in our test code.
Here we prepare for this by addressing the lints we'll enforce in
test codein the `lightning` crate.

Author: TheBlueMatt

lightning/src/chain/channelmonitor.rs

@@ -5598,7 +5598,7 @@ mod tests {
 		// and provides the claim preimages for the two pending HTLCs. The first update generates
 		// an error, but the point of this test is to ensure the later updates are still applied.
 		let monitor_updates = nodes[1].chain_monitor.monitor_updates.lock().unwrap();
-		let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().rev().next().unwrap().clone();
+		let mut replay_update = monitor_updates.get(&channel.2).unwrap().iter().next_back().unwrap().clone();
 		assert_eq!(replay_update.updates.len(), 1);
 		if let ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo { .. } = replay_update.updates[0] {
 		} else { panic!(); }
@@ -5736,7 +5736,7 @@ mod tests {
 		let nondust_htlcs = dummy_commitment_tx.nondust_htlcs();
 
 		monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
-			nondust_htlcs.into_iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
+			nondust_htlcs.iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
 		monitor.provide_latest_counterparty_commitment_tx(Txid::from_byte_array(Sha256::hash(b"1").to_byte_array()),
 			preimages_slice_to_htlc_outputs!(preimages[5..15]), 281474976710655, dummy_key, &logger);
 		monitor.provide_latest_counterparty_commitment_tx(Txid::from_byte_array(Sha256::hash(b"2").to_byte_array()),
@@ -5776,7 +5776,7 @@ mod tests {
 		// These HTLCs now have their output indices assigned
 		let nondust_htlcs = dummy_commitment_tx.nondust_htlcs();
 		monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
-			nondust_htlcs.into_iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
+			nondust_htlcs.iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
 		secret[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
 		monitor.provide_secret(281474976710653, secret.clone()).unwrap();
 		assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 12);
@@ -5789,7 +5789,7 @@ mod tests {
 		// These HTLCs now have their output indices assigned
 		let nondust_htlcs = dummy_commitment_tx.nondust_htlcs();
 		monitor.provide_latest_holder_commitment_tx(dummy_commitment_tx.clone(),
-			nondust_htlcs.into_iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
+			nondust_htlcs.iter().map(|htlc| (htlc.clone(), Some(dummy_sig), Some(dummy_source.clone()))).collect());
 		secret[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
 		monitor.provide_secret(281474976710652, secret.clone()).unwrap();
 		assert_eq!(monitor.inner.lock().unwrap().payment_preimages.len(), 5);

lightning/src/ln/blinded_payment_tests.rs

@@ -207,7 +207,7 @@ fn mpp_to_one_hop_blinded_path() {
 	create_announced_chan_between_nodes(&nodes, 0, 1);
 	create_announced_chan_between_nodes(&nodes, 0, 2);
 	let chan_upd_1_3 = create_announced_chan_between_nodes(&nodes, 1, 3).0.contents;
-	create_announced_chan_between_nodes(&nodes, 2, 3).0.contents;
+	create_announced_chan_between_nodes(&nodes, 2, 3);
 
 	// Ensure all nodes start at the same height.
 	connect_blocks(&nodes[0], 4*CHAN_CONFIRM_DEPTH + 1 - nodes[0].best_block_info().1);
@@ -1976,7 +1976,7 @@ fn test_trampoline_inbound_payment_decoding() {
 		&carol_update_add, &carol_node_signer, &logger, &secp_ctx
 	).unwrap_or_else(|_| panic!());
 
-	let _carol_trampoline_update_add = if let onion_utils::Hop::TrampolineForward { next_trampoline_hop_data, .. } = carol_peeled_onion {
+	if let onion_utils::Hop::TrampolineForward { next_trampoline_hop_data, .. } = carol_peeled_onion {
 		assert_eq!(next_trampoline_hop_data.next_trampoline, dave_node_id);
 	} else {
 		panic!();

lightning/src/ln/functional_test_utils.rs

@@ -1089,9 +1089,9 @@ macro_rules! unwrap_send_err {
 		let events = $node.node.get_and_clear_pending_events();
 		assert!(events.len() == 2);
 		match &events[0] {
-			crate::events::Event::PaymentPathFailed { failure, .. } => {
+			$crate::events::Event::PaymentPathFailed { failure, .. } => {
 				match failure {
-					crate::events::PathFailure::InitialSend { err } => {
+					$crate::events::PathFailure::InitialSend { err } => {
 						match err {
 							$type => { $check },
 							_ => panic!()
@@ -1103,7 +1103,7 @@ macro_rules! unwrap_send_err {
 			_ => panic!()
 		}
 		match &events[1] {
-			crate::events::Event::PaymentFailed { .. } => {},
+			$crate::events::Event::PaymentFailed { .. } => {},
 			_ => panic!()
 		}
 	}
@@ -2203,7 +2203,7 @@ macro_rules! get_payment_preimage_hash {
 		get_payment_preimage_hash!($dest_node, None)
 	};
 	($dest_node: expr, $min_value_msat: expr) => {
-		crate::get_payment_preimage_hash!($dest_node, $min_value_msat, None)
+		$crate::get_payment_preimage_hash!($dest_node, $min_value_msat, None)
 	};
 	($dest_node: expr, $min_value_msat: expr, $min_final_cltv_expiry_delta: expr) => {
 		$crate::ln::functional_test_utils::get_payment_preimage_hash(&$dest_node, $min_value_msat, $min_final_cltv_expiry_delta)

lightning/src/ln/functional_tests.rs

@@ -516,34 +516,35 @@ pub fn fake_network_test() {
 	send_payment(&nodes[1], &[&nodes[3]], 8000000);
 
 	// Do some rebalance loop payments, simultaneously
-	let mut hops = Vec::with_capacity(3);
-	hops.push(RouteHop {
-		pubkey: node_c_id,
-		node_features: NodeFeatures::empty(),
-		short_channel_id: chan_2.0.contents.short_channel_id,
-		channel_features: ChannelFeatures::empty(),
-		fee_msat: 0,
-		cltv_expiry_delta: chan_3.0.contents.cltv_expiry_delta as u32,
-		maybe_announced_channel: true,
-	});
-	hops.push(RouteHop {
-		pubkey: node_d_id,
-		node_features: NodeFeatures::empty(),
-		short_channel_id: chan_3.0.contents.short_channel_id,
-		channel_features: ChannelFeatures::empty(),
-		fee_msat: 0,
-		cltv_expiry_delta: chan_4.1.contents.cltv_expiry_delta as u32,
-		maybe_announced_channel: true,
-	});
-	hops.push(RouteHop {
-		pubkey: node_b_id,
-		node_features: nodes[1].node.node_features(),
-		short_channel_id: chan_4.0.contents.short_channel_id,
-		channel_features: nodes[1].node.channel_features(),
-		fee_msat: 1000000,
-		cltv_expiry_delta: TEST_FINAL_CLTV,
-		maybe_announced_channel: true,
-	});
+	let mut hops = vec![
+		RouteHop {
+			pubkey: node_c_id,
+			node_features: NodeFeatures::empty(),
+			short_channel_id: chan_2.0.contents.short_channel_id,
+			channel_features: ChannelFeatures::empty(),
+			fee_msat: 0,
+			cltv_expiry_delta: chan_3.0.contents.cltv_expiry_delta as u32,
+			maybe_announced_channel: true,
+		},
+		RouteHop {
+			pubkey: node_d_id,
+			node_features: NodeFeatures::empty(),
+			short_channel_id: chan_3.0.contents.short_channel_id,
+			channel_features: ChannelFeatures::empty(),
+			fee_msat: 0,
+			cltv_expiry_delta: chan_4.1.contents.cltv_expiry_delta as u32,
+			maybe_announced_channel: true,
+		},
+		RouteHop {
+			pubkey: node_b_id,
+			node_features: nodes[1].node.node_features(),
+			short_channel_id: chan_4.0.contents.short_channel_id,
+			channel_features: nodes[1].node.channel_features(),
+			fee_msat: 1000000,
+			cltv_expiry_delta: TEST_FINAL_CLTV,
+			maybe_announced_channel: true,
+		},
+	];
 	hops[1].fee_msat = chan_4.1.contents.fee_base_msat as u64
 		+ chan_4.1.contents.fee_proportional_millionths as u64 * hops[2].fee_msat as u64 / 1000000;
 	hops[0].fee_msat = chan_3.0.contents.fee_base_msat as u64
@@ -559,34 +560,35 @@ pub fn fake_network_test() {
 	let path: &[_] = &[&nodes[2], &nodes[3], &nodes[1]];
 	let payment_preimage_1 = send_along_route(&nodes[1], route, path, 1000000).0;
 
-	let mut hops = Vec::with_capacity(3);
-	hops.push(RouteHop {
-		pubkey: node_d_id,
-		node_features: NodeFeatures::empty(),
-		short_channel_id: chan_4.0.contents.short_channel_id,
-		channel_features: ChannelFeatures::empty(),
-		fee_msat: 0,
-		cltv_expiry_delta: chan_3.1.contents.cltv_expiry_delta as u32,
-		maybe_announced_channel: true,
-	});
-	hops.push(RouteHop {
-		pubkey: node_c_id,
-		node_features: NodeFeatures::empty(),
-		short_channel_id: chan_3.0.contents.short_channel_id,
-		channel_features: ChannelFeatures::empty(),
-		fee_msat: 0,
-		cltv_expiry_delta: chan_2.1.contents.cltv_expiry_delta as u32,
-		maybe_announced_channel: true,
-	});
-	hops.push(RouteHop {
-		pubkey: node_b_id,
-		node_features: nodes[1].node.node_features(),
-		short_channel_id: chan_2.0.contents.short_channel_id,
-		channel_features: nodes[1].node.channel_features(),
-		fee_msat: 1000000,
-		cltv_expiry_delta: TEST_FINAL_CLTV,
-		maybe_announced_channel: true,
-	});
+	let mut hops = vec![
+		RouteHop {
+			pubkey: node_d_id,
+			node_features: NodeFeatures::empty(),
+			short_channel_id: chan_4.0.contents.short_channel_id,
+			channel_features: ChannelFeatures::empty(),
+			fee_msat: 0,
+			cltv_expiry_delta: chan_3.1.contents.cltv_expiry_delta as u32,
+			maybe_announced_channel: true,
+		},
+		RouteHop {
+			pubkey: node_c_id,
+			node_features: NodeFeatures::empty(),
+			short_channel_id: chan_3.0.contents.short_channel_id,
+			channel_features: ChannelFeatures::empty(),
+			fee_msat: 0,
+			cltv_expiry_delta: chan_2.1.contents.cltv_expiry_delta as u32,
+			maybe_announced_channel: true,
+		},
+		RouteHop {
+			pubkey: node_b_id,
+			node_features: nodes[1].node.node_features(),
+			short_channel_id: chan_2.0.contents.short_channel_id,
+			channel_features: nodes[1].node.channel_features(),
+			fee_msat: 1000000,
+			cltv_expiry_delta: TEST_FINAL_CLTV,
+			maybe_announced_channel: true,
+		},
+	];
 	hops[1].fee_msat = chan_2.1.contents.fee_base_msat as u64
 		+ chan_2.1.contents.fee_proportional_millionths as u64 * hops[2].fee_msat as u64 / 1000000;
 	hops[0].fee_msat = chan_3.1.contents.fee_base_msat as u64
@@ -1498,9 +1500,8 @@ pub fn claim_htlc_outputs() {
 
 		// The ChannelMonitor should claim the accepted HTLC output separately from the offered
 		// HTLC and to_self outputs.
-		let accepted_claim = node_txn.iter().filter(|tx| tx.input.len() == 1).next().unwrap();
-		let offered_to_self_claim =
-			node_txn.iter().filter(|tx| tx.input.len() == 2).next().unwrap();
+		let accepted_claim = node_txn.iter().find(|tx| tx.input.len() == 1).unwrap();
+		let offered_to_self_claim = node_txn.iter().find(|tx| tx.input.len() == 2).unwrap();
 		check_spends!(accepted_claim, revoked_local_txn[0]);
 		check_spends!(offered_to_self_claim, revoked_local_txn[0]);
 		assert_eq!(
@@ -1512,7 +1513,7 @@ pub fn claim_htlc_outputs() {
 		witness_lens.insert(offered_to_self_claim.input[0].witness.last().unwrap().len());
 		witness_lens.insert(offered_to_self_claim.input[1].witness.last().unwrap().len());
 		assert_eq!(witness_lens.len(), 2);
-		assert_eq!(*witness_lens.iter().skip(0).next().unwrap(), 77); // revoked to_local
+		assert_eq!(*witness_lens.iter().next().unwrap(), 77); // revoked to_local
 		assert_eq!(*witness_lens.iter().skip(1).next().unwrap(), OFFERED_HTLC_SCRIPT_WEIGHT);
 
 		// Finally, mine the penalty transaction and check that we get an HTLC failure after
@@ -7542,7 +7543,7 @@ pub fn test_manually_accept_inbound_channel_request() {
 	};
 	match &events[1] {
 		crate::events::Event::ChannelPending { counterparty_node_id, .. } => {
-			assert_eq!(*&node_b_id, *counterparty_node_id);
+			assert_eq!(node_b_id, *counterparty_node_id);
 		},
 		_ => panic!("Unexpected event"),
 	};
@@ -7959,7 +7960,7 @@ pub fn test_preimage_storage() {
 
 	let node_a_id = nodes[0].node.get_our_node_id();
 
-	create_announced_chan_between_nodes(&nodes, 0, 1).0.contents.short_channel_id;
+	create_announced_chan_between_nodes(&nodes, 0, 1);
 
 	{
 		let (payment_hash, payment_secret) =
@@ -8002,7 +8003,7 @@ pub fn test_bad_secret_hash() {
 	let node_a_id = nodes[0].node.get_our_node_id();
 	let node_b_id = nodes[1].node.get_our_node_id();
 
-	create_announced_chan_between_nodes(&nodes, 0, 1).0.contents.short_channel_id;
+	create_announced_chan_between_nodes(&nodes, 0, 1);
 
 	let random_hash = PaymentHash([42; 32]);
 	let random_secret = PaymentSecret([43; 32]);
@@ -8195,7 +8196,7 @@ pub fn test_concurrent_monitor_claim() {
 	send_payment(&nodes[0], &[&nodes[1]], 10_000_000);
 
 	// Route a HTLC from node 0 to node 1 (but don't settle)
-	route_payment(&nodes[0], &[&nodes[1]], 9_000_000).0;
+	route_payment(&nodes[0], &[&nodes[1]], 9_000_000);
 
 	// Copy ChainMonitor to simulate watchtower Alice and update block height her ChannelMonitor timeout HTLC onchain
 	let chain_source = test_utils::TestChainSource::new(Network::Testnet);
@@ -10088,7 +10089,7 @@ fn do_test_max_dust_htlc_exposure(
 		}
 		{
 			let mut feerate_lock = chanmon_cfgs[0].fee_estimator.sat_per_kw.lock().unwrap();
-			*feerate_lock = *feerate_lock * 10;
+			*feerate_lock *= 10;
 		}
 		nodes[0].node.timer_tick_occurred();
 		check_added_monitors(&nodes[0], 1);
@@ -11745,7 +11746,7 @@ pub fn test_funding_signed_event() {
 	};
 	match &events[1] {
 		crate::events::Event::ChannelPending { counterparty_node_id, .. } => {
-			assert_eq!(*&node_b_id, *counterparty_node_id);
+			assert_eq!(node_b_id, *counterparty_node_id);
 		},
 		_ => panic!("Unexpected event"),
 	};

lightning/src/ln/monitor_tests.rs

@@ -761,7 +761,7 @@ fn do_test_claim_value_force_close(anchors: bool, prev_commitment_tx: bool) {
 	// Confirm node B's claim for node A to remove that claim from the aggregated claim transaction.
 	mine_transaction(&nodes[0], &b_broadcast_txn[0]);
 	let a_broadcast_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
-	let a_htlc_timeout_tx = a_broadcast_txn.into_iter().last().unwrap();
+	let a_htlc_timeout_tx = a_broadcast_txn.into_iter().next_back().unwrap();
 
 	// Once the HTLC-Timeout transaction confirms, A will no longer consider the HTLC
 	// "MaybeClaimable", but instead move it to "AwaitingConfirmations".

lightning/src/ln/msgs.rs

@@ -4563,7 +4563,7 @@ mod tests {
 		}
 		if disable {
 			let flag = target_value.last_mut().unwrap();
-			*flag = *flag | 1 << 1;
+			*flag |= 1 << 1;
 		}
 		target_value
 			.append(&mut <Vec<u8>>::from_hex("009000000000000f42400000271000000014").unwrap());

lightning/src/ln/payment_tests.rs

@@ -1747,7 +1747,7 @@ fn claimed_send_payment_idempotent() {
 	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 
-	create_announced_chan_between_nodes(&nodes, 0, 1).2;
+	create_announced_chan_between_nodes(&nodes, 0, 1);
 
 	let (route, hash_b, preimage_b, second_payment_secret) =
 		get_route_and_payment_hash!(nodes[0], nodes[1], 100_000);
@@ -1830,7 +1830,7 @@ fn abandoned_send_payment_idempotent() {
 	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
 	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 
-	create_announced_chan_between_nodes(&nodes, 0, 1).2;
+	create_announced_chan_between_nodes(&nodes, 0, 1);
 
 	let (route, hash_b, second_payment_preimage, second_payment_secret) =
 		get_route_and_payment_hash!(nodes[0], nodes[1], 100_000);
@@ -2434,14 +2434,14 @@ fn do_accept_underpaying_htlcs_config(num_mpp_parts: usize) {
 	assert_eq!(events.len(), 1);
 	match events[0] {
 		crate::events::Event::PaymentClaimable {
-			ref payment_hash,
+			payment_hash: pmt_hash,
 			ref purpose,
 			amount_msat,
 			counterparty_skimmed_fee_msat,
 			receiver_node_id,
 			..
 		} => {
-			assert_eq!(payment_hash, payment_hash);
+			assert_eq!(pmt_hash, payment_hash);
 			assert_eq!(amt_msat - skimmed_fee_msat * num_mpp_parts as u64, amount_msat);
 			assert_eq!(skimmed_fee_msat * num_mpp_parts as u64, counterparty_skimmed_fee_msat);
 			assert_eq!(node_c_id, receiver_node_id.unwrap());
@@ -3065,7 +3065,7 @@ fn fails_paying_after_rejected_by_payee() {
 	let node_a_id = nodes[0].node.get_our_node_id();
 	let node_b_id = nodes[1].node.get_our_node_id();
 
-	create_announced_chan_between_nodes(&nodes, 0, 1).0.contents.short_channel_id;
+	create_announced_chan_between_nodes(&nodes, 0, 1);
 
 	// Marshall data to send the payment
 	let amt_msat = 20_000;
@@ -4159,7 +4159,6 @@ fn do_claim_from_closed_chan(fail_payment: bool) {
 	send_msgs.sort_by(|a, _| {
 		let a_node_id =
 			if let MessageSendEvent::UpdateHTLCs { node_id, .. } = a { node_id } else { panic!() };
-		let node_b_id = node_b_id;
 		if *a_node_id == node_b_id {
 			Ordering::Less
 		} else {

lightning/src/ln/priv_short_conf_tests.rs

@@ -234,7 +234,7 @@ fn test_routed_scid_alias() {
 	let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, Some(no_announce_cfg), None]);
 	let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 
-	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 500_000_000).2;
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 500_000_000);
 	let mut as_channel_ready = create_unannounced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 500_000_000).0;
 
 	let last_hop = nodes[2].node.list_usable_channels();

lightning/src/onion_message/dns_resolution.rs

@@ -459,9 +459,7 @@ impl OMNameResolver {
 					.filter_map(
 						|rr| if let RR::Txt(txt) = rr { Some(txt.data.as_vec()) } else { None },
 					)
-					.filter_map(
-						|data| if let Ok(s) = String::from_utf8(data) { Some(s) } else { None },
-					)
+					.filter_map(|data| String::from_utf8(data).ok())
 					.filter(|data_string| data_string.len() > URI_PREFIX.len())
 					.filter(|data_string| {
 						data_string[..URI_PREFIX.len()].eq_ignore_ascii_case(URI_PREFIX)

lightning/src/onion_message/functional_tests.rs

@@ -361,7 +361,7 @@ fn add_channel_to_graph(
 
 fn pass_along_path(path: &Vec<MessengerNode>) {
 	let mut prev_node = &path[0];
-	for node in path.into_iter().skip(1) {
+	for node in path.iter().skip(1) {
 		let events = prev_node.messenger.release_pending_msgs();
 		let onion_msg = {
 			let msgs = events.get(&node.node_id).unwrap();