Remove FundingTxInput type alias in favor of ConfirmedUtxo

ConfirmedUtxo already documents its use as a funding input for v2
channel establishment and splicing, so the alias added a layer of
indirection without conveying additional information.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jkczyz

lightning/src/ln/channel.rs

@@ -56,9 +56,7 @@ use crate::ln::channelmanager::{
 	PendingHTLCStatus, RAACommitmentOrder, SentHTLCId, TrustedChannelFeatures, BREAKDOWN_TIMEOUT,
 	MAX_LOCAL_BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA,
 };
-use crate::ln::funding::{
-	FeeRateAdjustmentError, FundingContribution, FundingTemplate, FundingTxInput,
-};
+use crate::ln::funding::{FeeRateAdjustmentError, FundingContribution, FundingTemplate};
 use crate::ln::interactivetxs::{
 	AbortReason, HandleTxCompleteValue, InteractiveTxConstructor, InteractiveTxConstructorArgs,
 	InteractiveTxMessageSend, InteractiveTxSigningSession, SharedOwnedInput, SharedOwnedOutput,
@@ -87,7 +85,7 @@ use crate::util::errors::APIError;
 use crate::util::logger::{Level as LoggerLevel, Logger, Record, WithContext};
 use crate::util::scid_utils::{block_from_scid, scid_from_parts};
 use crate::util::ser::{Readable, ReadableArgs, RequiredWrapper, Writeable, Writer};
-use crate::util::wallet_utils::Input;
+use crate::util::wallet_utils::{ConfirmedUtxo, Input};
 use crate::{impl_readable_for_vec, impl_writeable_for_vec};
 
 use alloc::collections::{btree_map, BTreeMap};
@@ -3100,7 +3098,7 @@ impl FundingNegotiation {
 		funding: FundingScope, context: &ChannelContext<SP>, entropy_source: &ES,
 		holder_node_id: &PublicKey, our_funding_contribution: SignedAmount,
 		prev_funding_input: SharedOwnedInput, locktime: u32, feerate_sat_per_1000_weight: u32,
-		our_funding_inputs: Vec<FundingTxInput>, our_funding_outputs: Vec<TxOut>,
+		our_funding_inputs: Vec<ConfirmedUtxo>, our_funding_outputs: Vec<TxOut>,
 	) -> FundingNegotiation {
 		let funding_negotiation_context = FundingNegotiationContext {
 			is_initiator: false,
@@ -6905,7 +6903,7 @@ pub(super) struct FundingNegotiationContext {
 	pub shared_funding_input: Option<SharedOwnedInput>,
 	/// The funding inputs we will be contributing to the channel.
 	#[allow(dead_code)] // TODO(dual_funding): Remove once contribution to V2 channels is enabled.
-	pub our_funding_inputs: Vec<FundingTxInput>,
+	pub our_funding_inputs: Vec<ConfirmedUtxo>,
 	/// The funding outputs we will be contributing to the channel.
 	#[allow(dead_code)] // TODO(dual_funding): Remove once contribution to V2 channels is enabled.
 	pub our_funding_outputs: Vec<TxOut>,
@@ -15402,7 +15400,7 @@ impl<SP: SignerProvider> PendingV2Channel<SP> {
 	pub fn new_outbound<ES: EntropySource, F: FeeEstimator, L: Logger>(
 		fee_estimator: &LowerBoundedFeeEstimator<F>, entropy_source: &ES, signer_provider: &SP,
 		counterparty_node_id: PublicKey, their_features: &InitFeatures, funding_satoshis: u64,
-		funding_inputs: Vec<FundingTxInput>, user_id: u128, config: &UserConfig,
+		funding_inputs: Vec<ConfirmedUtxo>, user_id: u128, config: &UserConfig,
 		current_chain_height: u32, outbound_scid_alias: u64, funding_confirmation_target: ConfirmationTarget,
 		logger: L, trusted_channel_features: Option<TrustedChannelFeatures>,
 	) -> Result<Self, APIError> {

lightning/src/ln/functional_test_utils.rs

@@ -29,7 +29,7 @@ use crate::ln::channelmanager::{
 	AChannelManager, ChainParameters, ChannelManager, ChannelManagerReadArgs, PaymentId,
 	RAACommitmentOrder, TrustedChannelFeatures, MIN_CLTV_EXPIRY_DELTA,
 };
-use crate::ln::funding::{FundingContribution, FundingTxInput};
+use crate::ln::funding::FundingContribution;
 use crate::ln::msgs::{self, OpenChannel};
 use crate::ln::msgs::{
 	BaseMessageHandler, ChannelMessageHandler, MessageSendEvent, RoutingMessageHandler,
@@ -55,7 +55,7 @@ use crate::util::test_channel_signer::SignerOp;
 use crate::util::test_channel_signer::TestChannelSigner;
 use crate::util::test_utils::{self, TestLogger};
 use crate::util::test_utils::{TestChainMonitor, TestKeysInterface, TestScorer};
-use crate::util::wallet_utils::{WalletSourceSync, WalletSync};
+use crate::util::wallet_utils::{ConfirmedUtxo, WalletSourceSync, WalletSync};
 
 use bitcoin::amount::Amount;
 use bitcoin::block::{Block, Header, Version as BlockVersion};
@@ -1512,7 +1512,7 @@ fn internal_create_funding_transaction<'a, 'b, 'c>(
 /// Return the inputs (with prev tx), and the total witness weight for these inputs
 pub fn create_dual_funding_utxos_with_prev_txs(
 	node: &Node<'_, '_, '_>, utxo_values_in_satoshis: &[u64],
-) -> Vec<FundingTxInput> {
+) -> Vec<ConfirmedUtxo> {
 	// Ensure we have unique transactions per node by using the locktime.
 	let tx = Transaction {
 		version: TxVersion::TWO,
@@ -1536,7 +1536,7 @@ pub fn create_dual_funding_utxos_with_prev_txs(
 		.iter()
 		.enumerate()
 		.map(|(index, _)| index as u32)
-		.map(|vout| FundingTxInput::new_p2wpkh(tx.clone(), vout).unwrap())
+		.map(|vout| ConfirmedUtxo::new_p2wpkh(tx.clone(), vout).unwrap())
 		.collect()
 }
 

lightning/src/ln/funding.rs

@@ -24,7 +24,7 @@ use crate::ln::LN_MAX_MSG_LEN;
 use crate::prelude::*;
 use crate::util::native_async::MaybeSend;
 use crate::util::wallet_utils::{
-	CoinSelection, CoinSelectionSource, CoinSelectionSourceSync, Input,
+	CoinSelection, CoinSelectionSource, CoinSelectionSourceSync, ConfirmedUtxo, Input,
 };
 
 /// Error returned when a [`FundingContribution`] cannot be adjusted to a target feerate.
@@ -370,7 +370,7 @@ impl FundingTemplate {
 	/// when that is set. `max_feerate` is the highest feerate we are willing to tolerate if we end
 	/// up as the acceptor, and must be at least `min_feerate`.
 	pub fn splice_in_inputs(
-		self, inputs: Vec<FundingTxInput>, min_feerate: FeeRate, max_feerate: FeeRate,
+		self, inputs: Vec<ConfirmedUtxo>, min_feerate: FeeRate, max_feerate: FeeRate,
 	) -> Result<FundingContribution, FundingContributionError> {
 		self.with_prior_contribution(min_feerate, max_feerate).add_inputs(inputs)?.build()
 	}
@@ -466,8 +466,8 @@ impl FundingTemplate {
 }
 
 fn estimate_transaction_fee(
-	inputs: &[FundingTxInput], outputs: &[TxOut], change_output: Option<&TxOut>,
-	is_initiator: bool, is_splice: bool, feerate: FeeRate,
+	inputs: &[ConfirmedUtxo], outputs: &[TxOut], change_output: Option<&TxOut>, is_initiator: bool,
+	is_splice: bool, feerate: FeeRate,
 ) -> Amount {
 	let input_weight: u64 = inputs
 		.iter()
@@ -515,7 +515,7 @@ fn estimate_transaction_fee(
 	Weight::from_wu(weight) * feerate
 }
 
-fn validate_inputs(inputs: &[FundingTxInput]) -> Result<(), FundingContributionError> {
+fn validate_inputs(inputs: &[ConfirmedUtxo]) -> Result<(), FundingContributionError> {
 	let mut total_value = Amount::ZERO;
 	for (idx, input) in inputs.iter().enumerate() {
 		if inputs[..idx]
@@ -559,7 +559,7 @@ enum FundingInputs {
 	/// Replaces the contribution's inputs with the provided set and fully consumes them without a
 	/// change output. The amount added to the channel is recomputed from the input total minus fees,
 	/// while explicit withdrawal outputs still reduce the splice's net value.
-	ManuallySelected { inputs: Vec<FundingTxInput> },
+	ManuallySelected { inputs: Vec<ConfirmedUtxo> },
 }
 
 impl FundingInputs {
@@ -584,7 +584,7 @@ impl FundingInputs {
 		}
 	}
 
-	fn manually_selected_inputs(&self) -> &[FundingTxInput] {
+	fn manually_selected_inputs(&self) -> &[ConfirmedUtxo] {
 		match self {
 			FundingInputs::ManuallySelected { inputs } => inputs,
 			FundingInputs::CoinSelected { .. } => &[],
@@ -613,7 +613,7 @@ pub struct FundingContribution {
 	///
 	/// For coin-selected contributions, excess value is returned via [`Self::change_output`]. For
 	/// manually selected inputs, the full input value is consumed and no change output is created.
-	inputs: Vec<FundingTxInput>,
+	inputs: Vec<ConfirmedUtxo>,
 
 	/// The outputs to include in the funding transaction.
 	///
@@ -691,7 +691,7 @@ impl FundingContribution {
 	}
 
 	/// Returns the inputs included in this contribution.
-	pub fn inputs(&self) -> &[FundingTxInput] {
+	pub fn inputs(&self) -> &[ConfirmedUtxo] {
 		&self.inputs
 	}
 
@@ -827,7 +827,7 @@ impl FundingContribution {
 		Some(new_contribution_at_target_feerate)
 	}
 
-	pub(super) fn into_tx_parts(self) -> (Vec<FundingTxInput>, Vec<TxOut>) {
+	pub(super) fn into_tx_parts(self) -> (Vec<ConfirmedUtxo>, Vec<TxOut>) {
 		let FundingContribution { inputs, mut outputs, change_output, .. } = self;
 
 		if let Some(change_output) = change_output {
@@ -1131,10 +1131,6 @@ impl FundingContribution {
 	}
 }
 
-/// An input to contribute to a channel's funding transaction either when using the v2 channel
-/// establishment protocol or when splicing.
-pub type FundingTxInput = crate::util::wallet_utils::ConfirmedUtxo;
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 struct NoCoinSelectionSource;
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -1472,7 +1468,7 @@ impl FundingBuilder {
 	///
 	/// Returns [`FundingContributionError::InvalidSpliceValue`] if the builder already has a
 	/// coin-selected value request.
-	pub fn add_input(self, input: FundingTxInput) -> Result<Self, FundingContributionError> {
+	pub fn add_input(self, input: ConfirmedUtxo) -> Result<Self, FundingContributionError> {
 		self.0.add_input_inner(input).map(FundingBuilder)
 	}
 
@@ -1490,7 +1486,7 @@ impl FundingBuilder {
 	///
 	/// Returns [`FundingContributionError::InvalidSpliceValue`] if the builder already has a
 	/// coin-selected value request.
-	pub fn add_inputs(self, inputs: Vec<FundingTxInput>) -> Result<Self, FundingContributionError> {
+	pub fn add_inputs(self, inputs: Vec<ConfirmedUtxo>) -> Result<Self, FundingContributionError> {
 		self.0.add_inputs_inner(inputs).map(FundingBuilder)
 	}
 
@@ -1585,7 +1581,7 @@ impl<State> FundingBuilderInner<State> {
 		Ok(self)
 	}
 
-	fn add_input_inner(mut self, input: FundingTxInput) -> Result<Self, FundingContributionError> {
+	fn add_input_inner(mut self, input: ConfirmedUtxo) -> Result<Self, FundingContributionError> {
 		match &mut self.funding_inputs {
 			None => {
 				self.funding_inputs = Some(FundingInputs::ManuallySelected { inputs: vec![input] })
@@ -1599,7 +1595,7 @@ impl<State> FundingBuilderInner<State> {
 	}
 
 	fn add_inputs_inner(
-		mut self, inputs: Vec<FundingTxInput>,
+		mut self, inputs: Vec<ConfirmedUtxo>,
 	) -> Result<Self, FundingContributionError> {
 		match &mut self.funding_inputs {
 			None => self.funding_inputs = Some(FundingInputs::ManuallySelected { inputs }),
@@ -1875,11 +1871,11 @@ impl<W: CoinSelectionSourceSync> SyncFundingBuilder<W> {
 mod tests {
 	use super::{
 		estimate_transaction_fee, FeeRateAdjustmentError, FundingBuilder, FundingContribution,
-		FundingContributionError, FundingInputMode, FundingTemplate, FundingTxInput,
-		SyncCoinSelectionSource, SyncFundingBuilder,
+		FundingContributionError, FundingInputMode, FundingTemplate, SyncCoinSelectionSource,
+		SyncFundingBuilder,
 	};
 	use crate::chain::ClaimId;
-	use crate::util::wallet_utils::{CoinSelection, CoinSelectionSourceSync, Input};
+	use crate::util::wallet_utils::{CoinSelection, CoinSelectionSourceSync, ConfirmedUtxo, Input};
 	use bitcoin::hashes::Hash;
 	use bitcoin::transaction::{Transaction, TxOut, Version};
 	use bitcoin::{Amount, FeeRate, Psbt, ScriptBuf, SignedAmount, WPubkeyHash, WScriptHash};
@@ -1960,7 +1956,7 @@ mod tests {
 	}
 
 	#[rustfmt::skip]
-	fn funding_input_sats(input_value_sats: u64) -> FundingTxInput {
+	fn funding_input_sats(input_value_sats: u64) -> ConfirmedUtxo {
 		let prevout = TxOut {
 			value: Amount::from_sat(input_value_sats),
 			script_pubkey: ScriptBuf::new_p2wpkh(&WPubkeyHash::all_zeros()),
@@ -1970,7 +1966,7 @@ mod tests {
 			version: Version::TWO, lock_time: bitcoin::absolute::LockTime::ZERO,
 		};
 
-		FundingTxInput::new_p2wpkh(prevtx, 0).unwrap()
+		ConfirmedUtxo::new_p2wpkh(prevtx, 0).unwrap()
 	}
 
 	fn funding_output_sats(output_value_sats: u64) -> TxOut {
@@ -1995,7 +1991,7 @@ mod tests {
 	}
 
 	struct MustPayToWallet {
-		utxo: FundingTxInput,
+		utxo: ConfirmedUtxo,
 		change_output: Option<TxOut>,
 		expected_must_pay_to_values: Vec<Amount>,
 	}
@@ -2805,7 +2801,7 @@ mod tests {
 		assert!(prevtx.serialized_length() > crate::ln::LN_MAX_MSG_LEN);
 
 		let wallet = SingleUtxoWallet {
-			utxo: FundingTxInput::new_p2wpkh(prevtx, 0).unwrap(),
+			utxo: ConfirmedUtxo::new_p2wpkh(prevtx, 0).unwrap(),
 			change_output: None,
 		};
 		assert!(matches!(
@@ -3713,7 +3709,7 @@ mod tests {
 
 	/// A mock wallet that returns a single UTXO for coin selection.
 	struct SingleUtxoWallet {
-		utxo: FundingTxInput,
+		utxo: ConfirmedUtxo,
 		change_output: Option<TxOut>,
 	}