Remove InvoicePayer and replace with util methods
authorValentine Wallace <vwallace@protonmail.com>
Fri, 3 Feb 2023 01:08:00 +0000 (20:08 -0500)
committerValentine Wallace <vwallace@protonmail.com>
Mon, 6 Feb 2023 21:28:23 +0000 (16:28 -0500)
lightning-background-processor/src/lib.rs
lightning-invoice/src/payment.rs
lightning-invoice/src/utils.rs

index 16e06780dfce48ade113ddd97aaf06860c6f1596..087aa1747221d26ee07fd4ae26afbdfef0464614 100644 (file)
@@ -659,7 +659,7 @@ mod tests {
        use bitcoin::secp256k1::{SecretKey, PublicKey, Secp256k1};
        use lightning::chain::{BestBlock, Confirm, chainmonitor};
        use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
-       use lightning::chain::keysinterface::{InMemorySigner, EntropySource, KeysManager};
+       use lightning::chain::keysinterface::{InMemorySigner, KeysManager};
        use lightning::chain::transaction::OutPoint;
        use lightning::get_event_msg;
        use lightning::ln::PaymentHash;
@@ -676,7 +676,6 @@ mod tests {
        use lightning::util::ser::Writeable;
        use lightning::util::test_utils;
        use lightning::util::persist::KVStorePersister;
-       use lightning_invoice::payment::{InvoicePayer, Retry};
        use lightning_persister::FilesystemPersister;
        use std::collections::VecDeque;
        use std::fs;
@@ -1326,22 +1325,6 @@ mod tests {
                assert_eq!(network_graph.read_only().channels().len(), 0);
        }
 
-       #[test]
-       fn test_invoice_payer() {
-               let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
-               let random_seed_bytes = keys_manager.get_secure_random_bytes();
-               let nodes = create_nodes(2, "test_invoice_payer".to_string());
-
-               // Initiate the background processors to watch each node.
-               let data_dir = nodes[0].persister.get_data_dir();
-               let persister = Arc::new(Persister::new(data_dir));
-               let router = Arc::new(DefaultRouter::new(Arc::clone(&nodes[0].network_graph), Arc::clone(&nodes[0].logger), random_seed_bytes, Arc::clone(&nodes[0].scorer)));
-               let invoice_payer = Arc::new(InvoicePayer::new(Arc::clone(&nodes[0].node), router, Arc::clone(&nodes[0].logger), |_: _| {}, Retry::Attempts(2)));
-               let event_handler = Arc::clone(&invoice_payer);
-               let bg_processor = BackgroundProcessor::start(persister, event_handler, nodes[0].chain_monitor.clone(), nodes[0].node.clone(), nodes[0].no_gossip_sync(), nodes[0].peer_manager.clone(), nodes[0].logger.clone(), Some(nodes[0].scorer.clone()));
-               assert!(bg_processor.stop().is_ok());
-       }
-
        #[test]
        fn test_payment_path_scoring() {
                // Ensure that we update the scorer when relevant events are processed. In this case, we ensure
index 89ff242a268781b61983de488063a064a1fa5699..0ffbae5fad5004804a465b1cbcd1335dc2a34907 100644 (file)
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
-//! A module for paying Lightning invoices and sending spontaneous payments.
-//!
-//! Defines an [`InvoicePayer`] utility for sending payments, parameterized by [`Payer`] and
-//! [`Router`] traits. Implementations of [`Payer`] provide the payer's node id, channels, and means
-//! to send a payment over a [`Route`]. Implementations of [`Router`] find a [`Route`] between payer
-//! and payee using information provided by the payer and from the payee's [`Invoice`], when
-//! applicable.
-//!
-//! [`InvoicePayer`] uses its [`Router`] parameterization for optionally notifying scorers upon
-//! receiving the [`Event::PaymentPathFailed`] and [`Event::PaymentPathSuccessful`] events.
-//! It also does the same for payment probe failure and success events using [`Event::ProbeFailed`]
-//! and [`Event::ProbeSuccessful`].
-//!
-//! [`InvoicePayer`] is capable of retrying failed payments. It accomplishes this by implementing
-//! [`EventHandler`] which decorates a user-provided handler. It will intercept any
-//! [`Event::PaymentPathFailed`] events and retry the failed paths for a fixed number of total
-//! attempts or until retry is no longer possible. In such a situation, [`InvoicePayer`] will pass
-//! along the events to the user-provided handler.
-//!
-//! # Example
-//!
-//! ```
-//! # extern crate lightning;
-//! # extern crate lightning_invoice;
-//! # extern crate secp256k1;
-//! #
-//! # use lightning::io;
-//! # use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-//! # use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
-//! # use lightning::ln::msgs::LightningError;
-//! # use lightning::routing::gossip::NodeId;
-//! # use lightning::routing::router::{InFlightHtlcs, Route, RouteHop, RouteParameters, Router};
-//! # use lightning::routing::scoring::{ChannelUsage, Score};
-//! # use lightning::util::events::{Event, EventHandler, EventsProvider};
-//! # use lightning::util::logger::{Logger, Record};
-//! # use lightning::util::ser::{Writeable, Writer};
-//! # use lightning_invoice::Invoice;
-//! # use lightning_invoice::payment::{InvoicePayer, Payer, Retry};
-//! # use secp256k1::PublicKey;
-//! # use std::cell::RefCell;
-//! # use std::ops::Deref;
-//! #
-//! # struct FakeEventProvider {}
-//! # impl EventsProvider for FakeEventProvider {
-//! #     fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {}
-//! # }
-//! #
-//! # struct FakePayer {}
-//! # impl Payer for FakePayer {
-//! #     fn node_id(&self) -> PublicKey { unimplemented!() }
-//! #     fn first_hops(&self) -> Vec<ChannelDetails> { unimplemented!() }
-//! #     fn send_payment(
-//! #         &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
-//! #         payment_id: PaymentId
-//! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
-//! #     fn send_spontaneous_payment(
-//! #         &self, route: &Route, payment_preimage: PaymentPreimage, payment_id: PaymentId,
-//! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
-//! #     fn retry_payment(
-//! #         &self, route: &Route, payment_id: PaymentId
-//! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
-//! #     fn abandon_payment(&self, payment_id: PaymentId) { unimplemented!() }
-//! #     fn inflight_htlcs(&self) -> InFlightHtlcs { unimplemented!() }
-//! # }
-//! #
-//! # struct FakeRouter {}
-//! # impl Router for FakeRouter {
-//! #     fn find_route(
-//! #         &self, payer: &PublicKey, params: &RouteParameters,
-//! #         first_hops: Option<&[&ChannelDetails]>, _inflight_htlcs: &InFlightHtlcs
-//! #     ) -> Result<Route, LightningError> { unimplemented!() }
-//! #     fn notify_payment_path_failed(&self, path: &[&RouteHop], short_channel_id: u64) {  unimplemented!() }
-//! #     fn notify_payment_path_successful(&self, path: &[&RouteHop]) {  unimplemented!() }
-//! #     fn notify_payment_probe_successful(&self, path: &[&RouteHop]) {  unimplemented!() }
-//! #     fn notify_payment_probe_failed(&self, path: &[&RouteHop], short_channel_id: u64) { unimplemented!() }
-//! # }
-//! #
-//! # struct FakeScorer {}
-//! # impl Writeable for FakeScorer {
-//! #     fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> { unimplemented!(); }
-//! # }
-//! # impl Score for FakeScorer {
-//! #     fn channel_penalty_msat(
-//! #         &self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId, _usage: ChannelUsage
-//! #     ) -> u64 { 0 }
-//! #     fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
-//! #     fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
-//! #     fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
-//! #     fn probe_successful(&mut self, _path: &[&RouteHop]) {}
-//! # }
-//! #
-//! # struct FakeLogger {}
-//! # impl Logger for FakeLogger {
-//! #     fn log(&self, record: &Record) { unimplemented!() }
-//! # }
-//! #
-//! # fn main() {
-//! let event_handler = |event: Event| {
-//!     match event {
-//!         Event::PaymentPathFailed { .. } => println!("payment failed after retries"),
-//!         Event::PaymentSent { .. } => println!("payment successful"),
-//!         _ => {},
-//!     }
-//! };
-//! # let payer = FakePayer {};
-//! # let router = FakeRouter {};
-//! # let scorer = RefCell::new(FakeScorer {});
-//! # let logger = FakeLogger {};
-//! let invoice_payer = InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-//!
-//! let invoice = "...";
-//! if let Ok(invoice) = invoice.parse::<Invoice>() {
-//!     invoice_payer.pay_invoice(&invoice).unwrap();
-//!
-//! # let event_provider = FakeEventProvider {};
-//!     loop {
-//!         event_provider.process_pending_events(&invoice_payer);
-//!     }
-//! }
-//! # }
-//! ```
-//!
-//! # Note
-//!
-//! The [`Route`] is computed before each payment attempt. Any updates affecting path finding such
-//! as updates to the network graph or changes to channel scores should be applied prior to
-//! retries, typically by way of composing [`EventHandler`]s accordingly.
+//! Convenient utilities for paying Lightning invoices and sending spontaneous payments.
 
 use crate::Invoice;
 
 use bitcoin_hashes::Hash;
-use bitcoin_hashes::sha256::Hash as Sha256;
 
-use crate::prelude::*;
-use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
-use lightning::ln::msgs::LightningError;
-use lightning::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteParameters, Router};
-use lightning::util::events::{Event, EventHandler};
+use lightning::chain;
+use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
+use lightning::chain::keysinterface::{NodeSigner, SignerProvider, EntropySource};
+use lightning::ln::{PaymentHash, PaymentSecret};
+use lightning::ln::channelmanager::{ChannelManager, PaymentId, PaymentSendFailure, Retry};
+use lightning::routing::router::{PaymentParameters, RouteParameters, Router};
 use lightning::util::logger::Logger;
-use crate::time_utils::Time;
-use crate::sync::Mutex;
 
-use secp256k1::PublicKey;
-
-use core::fmt;
-use core::fmt::{Debug, Display, Formatter};
-use core::future::Future;
+use core::fmt::Debug;
 use core::ops::Deref;
 use core::time::Duration;
-#[cfg(feature = "std")]
-use std::time::SystemTime;
 
-/// A utility for paying [`Invoice`]s and sending spontaneous payments.
+/// Pays the given [`Invoice`], retrying if needed based on [`Retry`].
 ///
-/// See [module-level documentation] for details.
+/// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
+/// as the payment is still pending. Once the payment completes or fails, you must ensure that
+/// a second payment with the same [`PaymentHash`] is never sent.
 ///
-/// [module-level documentation]: crate::payment
-pub type InvoicePayer<P, R, L, E> = InvoicePayerUsingTime::<P, R, L, E, ConfiguredTime>;
-
-#[cfg(not(feature = "no-std"))]
-type ConfiguredTime = std::time::Instant;
-#[cfg(feature = "no-std")]
-use crate::time_utils;
-#[cfg(feature = "no-std")]
-type ConfiguredTime = time_utils::Eternity;
-
-/// Sealed trait with a blanket implementation to allow both sync and async implementations of event
-/// handling to exist within the InvoicePayer.
-mod sealed {
-       pub trait BaseEventHandler {}
-       impl<T> BaseEventHandler for T {}
-}
-
-/// (C-not exported) generally all users should use the [`InvoicePayer`] type alias.
-pub struct InvoicePayerUsingTime<
-       P: Deref,
-       R: Deref,
-       L: Deref,
-       E: sealed::BaseEventHandler,
-       T: Time
-> where
-       P::Target: Payer,
-       R::Target: Router,
-       L::Target: Logger,
+/// If you wish to use a different payment idempotency token, see [`pay_invoice_with_id`].
+pub fn pay_invoice<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
+       invoice: &Invoice, retry_strategy: Retry,
+       channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
+) -> Result<PaymentId, PaymentError>
+where
+               M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+               T::Target: BroadcasterInterface,
+               ES::Target: EntropySource,
+               NS::Target: NodeSigner,
+               SP::Target: SignerProvider,
+               F::Target: FeeEstimator,
+               R::Target: Router,
+               L::Target: Logger,
 {
-       payer: P,
-       router: R,
-       logger: L,
-       event_handler: E,
-       /// Caches the overall attempts at making a payment, which is updated prior to retrying.
-       payment_cache: Mutex<HashMap<PaymentHash, PaymentAttempts<T>>>,
-       retry: Retry,
-}
-
-/// Storing minimal payment attempts information required for determining if a outbound payment can
-/// be retried.
-#[derive(Clone, Copy)]
-struct PaymentAttempts<T: Time> {
-       /// This count will be incremented only after the result of the attempt is known. When it's 0,
-       /// it means the result of the first attempt is now known yet.
-       count: usize,
-       /// This field is only used when retry is [`Retry::Timeout`] which is only build with feature std
-       first_attempted_at: T
+       let payment_id = PaymentId(invoice.payment_hash().into_inner());
+       pay_invoice_with_id(invoice, payment_id, retry_strategy, channelmanager)
+               .map(|()| payment_id)
 }
 
-impl<T: Time> PaymentAttempts<T> {
-       fn new() -> Self {
-               PaymentAttempts {
-                       count: 0,
-                       first_attempted_at: T::now()
-               }
-       }
+/// Pays the given [`Invoice`] with a custom idempotency key, retrying if needed based on [`Retry`].
+///
+/// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
+/// payment completes or fails, no idempotency guarantees are made.
+///
+/// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
+/// has never been paid before.
+///
+/// See [`pay_invoice`] for a variant which uses the [`PaymentHash`] for the idempotency token.
+pub fn pay_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
+       invoice: &Invoice, payment_id: PaymentId, retry_strategy: Retry,
+       channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
+) -> Result<(), PaymentError>
+where
+               M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+               T::Target: BroadcasterInterface,
+               ES::Target: EntropySource,
+               NS::Target: NodeSigner,
+               SP::Target: SignerProvider,
+               F::Target: FeeEstimator,
+               R::Target: Router,
+               L::Target: Logger,
+{
+       let amt_msat = invoice.amount_milli_satoshis().ok_or(PaymentError::Invoice("amount missing"))?;
+       pay_invoice_using_amount(invoice, amt_msat, payment_id, retry_strategy, channelmanager)
 }
 
-impl<T: Time> Display for PaymentAttempts<T> {
-       fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
-               #[cfg(feature = "no-std")]
-               return write!( f, "attempts: {}", self.count);
-               #[cfg(not(feature = "no-std"))]
-               return write!(
-                       f,
-                       "attempts: {}, duration: {}s",
-                       self.count,
-                       T::now().duration_since(self.first_attempted_at).as_secs()
-               );
-       }
+/// Pays the given zero-value [`Invoice`] using the given amount, retrying if needed based on
+/// [`Retry`].
+///
+/// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
+/// as the payment is still pending. Once the payment completes or fails, you must ensure that
+/// a second payment with the same [`PaymentHash`] is never sent.
+///
+/// If you wish to use a different payment idempotency token, see
+/// [`pay_zero_value_invoice_with_id`].
+pub fn pay_zero_value_invoice<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
+       invoice: &Invoice, amount_msats: u64, retry_strategy: Retry,
+       channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
+) -> Result<PaymentId, PaymentError>
+where
+               M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+               T::Target: BroadcasterInterface,
+               ES::Target: EntropySource,
+               NS::Target: NodeSigner,
+               SP::Target: SignerProvider,
+               F::Target: FeeEstimator,
+               R::Target: Router,
+               L::Target: Logger,
+{
+       let payment_id = PaymentId(invoice.payment_hash().into_inner());
+       pay_zero_value_invoice_with_id(invoice, amount_msats, payment_id, retry_strategy,
+               channelmanager)
+               .map(|()| payment_id)
 }
 
-/// A trait defining behavior of an [`Invoice`] payer.
-///
-/// While the behavior of [`InvoicePayer`] provides idempotency of duplicate `send_*payment` calls
-/// with the same [`PaymentHash`], it is up to the `Payer` to provide idempotency across restarts.
+/// Pays the given zero-value [`Invoice`] using the given amount and custom idempotency key,
+/// , retrying if needed based on [`Retry`].
 ///
-/// [`ChannelManager`] provides idempotency for duplicate payments with the same [`PaymentId`].
+/// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
+/// payment completes or fails, no idempotency guarantees are made.
 ///
-/// In order to trivially ensure idempotency for payments, the default `Payer` implementation
-/// reuses the [`PaymentHash`] bytes as the [`PaymentId`]. Custom implementations wishing to
-/// provide payment idempotency with a different idempotency key (i.e. [`PaymentId`]) should map
-/// the [`Invoice`] or spontaneous payment target pubkey to their own idempotency key.
+/// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
+/// has never been paid before.
 ///
-/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
-pub trait Payer {
-       /// Returns the payer's node id.
-       fn node_id(&self) -> PublicKey;
-
-       /// Returns the payer's channels.
-       fn first_hops(&self) -> Vec<ChannelDetails>;
-
-       /// Sends a payment over the Lightning Network using the given [`Route`].
-       fn send_payment(
-               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
-               payment_id: PaymentId
-       ) -> Result<(), PaymentSendFailure>;
-
-       /// Sends a spontaneous payment over the Lightning Network using the given [`Route`].
-       fn send_spontaneous_payment(
-               &self, route: &Route, payment_preimage: PaymentPreimage, payment_id: PaymentId
-       ) -> Result<(), PaymentSendFailure>;
-
-       /// Retries a failed payment path for the [`PaymentId`] using the given [`Route`].
-       fn retry_payment(&self, route: &Route, payment_id: PaymentId) -> Result<(), PaymentSendFailure>;
-
-       /// Signals that no further retries for the given payment will occur.
-       fn abandon_payment(&self, payment_id: PaymentId);
-
-       /// Construct an [`InFlightHtlcs`] containing information about currently used up liquidity
-       /// across payments.
-       fn inflight_htlcs(&self) -> InFlightHtlcs;
+/// See [`pay_zero_value_invoice`] for a variant which uses the [`PaymentHash`] for the
+/// idempotency token.
+pub fn pay_zero_value_invoice_with_id<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref>(
+       invoice: &Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
+       channelmanager: &ChannelManager<M, T, ES, NS, SP, F, R, L>
+) -> Result<(), PaymentError>
+where
+               M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+               T::Target: BroadcasterInterface,
+               ES::Target: EntropySource,
+               NS::Target: NodeSigner,
+               SP::Target: SignerProvider,
+               F::Target: FeeEstimator,
+               R::Target: Router,
+               L::Target: Logger,
+{
+       if invoice.amount_milli_satoshis().is_some() {
+               Err(PaymentError::Invoice("amount unexpected"))
+       } else {
+               pay_invoice_using_amount(invoice, amount_msats, payment_id, retry_strategy,
+                       channelmanager)
+       }
 }
 
-/// Strategies available to retry payment path failures for an [`Invoice`].
-///
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
-pub enum Retry {
-       /// Max number of attempts to retry payment.
-       ///
-       /// Note that this is the number of *path* failures, not full payment retries. For multi-path
-       /// payments, if this is less than the total number of paths, we will never even retry all of the
-       /// payment's paths.
-       Attempts(usize),
-       #[cfg(feature = "std")]
-       /// Time elapsed before abandoning retries for a payment.
-       Timeout(Duration),
+fn pay_invoice_using_amount<P: Deref>(
+       invoice: &Invoice, amount_msats: u64, payment_id: PaymentId, retry_strategy: Retry,
+       payer: P
+) -> Result<(), PaymentError> where P::Target: Payer {
+       let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
+       let payment_secret = Some(invoice.payment_secret().clone());
+       let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
+               invoice.min_final_cltv_expiry_delta() as u32)
+               .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs())
+               .with_route_hints(invoice.route_hints());
+       if let Some(features) = invoice.features() {
+               payment_params = payment_params.with_features(features.clone());
+       }
+       let route_params = RouteParameters {
+               payment_params,
+               final_value_msat: amount_msats,
+               final_cltv_expiry_delta: invoice.min_final_cltv_expiry_delta() as u32,
+       };
+
+       payer.send_payment(payment_hash, &payment_secret, payment_id, route_params, retry_strategy)
 }
 
-impl Retry {
-       fn is_retryable_now<T: Time>(&self, attempts: &PaymentAttempts<T>) -> bool {
-               match (self, attempts) {
-                       (Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
-                               max_retry_count >= &count
-                       },
-                       #[cfg(feature = "std")]
-                       (Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. } ) =>
-                               *max_duration >= T::now().duration_since(*first_attempted_at),
-               }
-       }
+fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
+       invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 }
 
 /// An error that may occur when making a payment.
@@ -311,478 +171,115 @@ impl Retry {
 pub enum PaymentError {
        /// An error resulting from the provided [`Invoice`] or payment hash.
        Invoice(&'static str),
-       /// An error occurring when finding a route.
-       Routing(LightningError),
        /// An error occurring when sending a payment.
        Sending(PaymentSendFailure),
 }
 
-impl<P: Deref, R: Deref, L: Deref, E: sealed::BaseEventHandler, T: Time>
-       InvoicePayerUsingTime<P, R, L, E, T>
-where
-       P::Target: Payer,
-       R::Target: Router,
-       L::Target: Logger,
-{
-       /// Creates an invoice payer that retries failed payment paths.
-       ///
-       /// Will forward any [`Event::PaymentPathFailed`] events to the decorated `event_handler` once
-       /// `retry` has been exceeded for a given [`Invoice`].
-       pub fn new(
-               payer: P, router: R, logger: L, event_handler: E, retry: Retry
-       ) -> Self {
-               Self {
-                       payer,
-                       router,
-                       logger,
-                       event_handler,
-                       payment_cache: Mutex::new(HashMap::new()),
-                       retry,
-               }
-       }
-
-       /// Pays the given [`Invoice`], caching it for later use in case a retry is needed.
-       ///
-       /// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
-       /// as the payment is still pending. Once the payment completes or fails, you must ensure that
-       /// a second payment with the same [`PaymentHash`] is never sent.
-       ///
-       /// If you wish to use a different payment idempotency token, see
-       /// [`Self::pay_invoice_with_id`].
-       pub fn pay_invoice(&self, invoice: &Invoice) -> Result<PaymentId, PaymentError> {
-               let payment_id = PaymentId(invoice.payment_hash().into_inner());
-               self.pay_invoice_with_id(invoice, payment_id).map(|()| payment_id)
-       }
-
-       /// Pays the given [`Invoice`] with a custom idempotency key, caching the invoice for later use
-       /// in case a retry is needed.
-       ///
-       /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
-       /// payment completes or fails, no idempotency guarantees are made.
-       ///
-       /// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
-       /// has never been paid before.
-       ///
-       /// See [`Self::pay_invoice`] for a variant which uses the [`PaymentHash`] for the idempotency
-       /// token.
-       pub fn pay_invoice_with_id(&self, invoice: &Invoice, payment_id: PaymentId) -> Result<(), PaymentError> {
-               if invoice.amount_milli_satoshis().is_none() {
-                       Err(PaymentError::Invoice("amount missing"))
-               } else {
-                       self.pay_invoice_using_amount(invoice, None, payment_id)
-               }
-       }
-
-       /// Pays the given zero-value [`Invoice`] using the given amount, caching it for later use in
-       /// case a retry is needed.
-       ///
-       /// [`Invoice::payment_hash`] is used as the [`PaymentId`], which ensures idempotency as long
-       /// as the payment is still pending. Once the payment completes or fails, you must ensure that
-       /// a second payment with the same [`PaymentHash`] is never sent.
-       ///
-       /// If you wish to use a different payment idempotency token, see
-       /// [`Self::pay_zero_value_invoice_with_id`].
-       pub fn pay_zero_value_invoice(
-               &self, invoice: &Invoice, amount_msats: u64
-       ) -> Result<PaymentId, PaymentError> {
-               let payment_id = PaymentId(invoice.payment_hash().into_inner());
-               self.pay_zero_value_invoice_with_id(invoice, amount_msats, payment_id).map(|()| payment_id)
-       }
-
-       /// Pays the given zero-value [`Invoice`] using the given amount and custom idempotency key,
-       /// caching the invoice for later use in case a retry is needed.
-       ///
-       /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
-       /// payment completes or fails, no idempotency guarantees are made.
-       ///
-       /// You should ensure that the [`Invoice::payment_hash`] is unique and the same [`PaymentHash`]
-       /// has never been paid before.
-       ///
-       /// See [`Self::pay_zero_value_invoice`] for a variant which uses the [`PaymentHash`] for the
-       /// idempotency token.
-       pub fn pay_zero_value_invoice_with_id(
-               &self, invoice: &Invoice, amount_msats: u64, payment_id: PaymentId
-       ) -> Result<(), PaymentError> {
-               if invoice.amount_milli_satoshis().is_some() {
-                       Err(PaymentError::Invoice("amount unexpected"))
-               } else {
-                       self.pay_invoice_using_amount(invoice, Some(amount_msats), payment_id)
-               }
-       }
-
-       fn pay_invoice_using_amount(
-               &self, invoice: &Invoice, amount_msats: Option<u64>, payment_id: PaymentId
-       ) -> Result<(), PaymentError> {
-               debug_assert!(invoice.amount_milli_satoshis().is_some() ^ amount_msats.is_some());
-
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               match self.payment_cache.lock().unwrap().entry(payment_hash) {
-                       hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
-                       hash_map::Entry::Vacant(entry) => entry.insert(PaymentAttempts::new()),
-               };
-
-               let payment_secret = Some(invoice.payment_secret().clone());
-               let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key(),
-                               invoice.min_final_cltv_expiry_delta() as u32)
-                       .with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs())
-                       .with_route_hints(invoice.route_hints());
-               if let Some(features) = invoice.features() {
-                       payment_params = payment_params.with_features(features.clone());
-               }
-               let route_params = RouteParameters {
-                       payment_params,
-                       final_value_msat: invoice.amount_milli_satoshis().or(amount_msats).unwrap(),
-                       final_cltv_expiry_delta: invoice.min_final_cltv_expiry_delta() as u32,
-               };
-
-               let send_payment = |route: &Route| {
-                       self.payer.send_payment(route, payment_hash, &payment_secret, payment_id)
-               };
-
-               self.pay_internal(&route_params, payment_hash, send_payment)
-                       .map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
-       }
-
-       /// Pays `pubkey` an amount using the hash of the given preimage, caching it for later use in
-       /// case a retry is needed.
-       ///
-       /// The hash of the [`PaymentPreimage`] is used as the [`PaymentId`], which ensures idempotency
-       /// as long as the payment is still pending. Once the payment completes or fails, you must
-       /// ensure that a second payment with the same [`PaymentPreimage`] is never sent.
-       pub fn pay_pubkey(
-               &self, pubkey: PublicKey, payment_preimage: PaymentPreimage, amount_msats: u64,
-               final_cltv_expiry_delta: u32
-       ) -> Result<PaymentId, PaymentError> {
-               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
-               let payment_id = PaymentId(payment_hash.0);
-               self.do_pay_pubkey(pubkey, payment_preimage, payment_hash, payment_id, amount_msats,
-                               final_cltv_expiry_delta)
-                       .map(|()| payment_id)
-       }
-
-       /// Pays `pubkey` an amount using the hash of the given preimage and a custom idempotency key,
-       /// caching the invoice for later use in case a retry is needed.
-       ///
-       /// Note that idempotency is only guaranteed as long as the payment is still pending. Once the
-       /// payment completes or fails, no idempotency guarantees are made.
+/// A trait defining behavior of an [`Invoice`] payer.
+///
+/// Useful for unit testing internal methods.
+trait Payer {
+       /// Sends a payment over the Lightning Network using the given [`Route`].
        ///
-       /// You should ensure that the [`PaymentPreimage`] is unique and the corresponding
-       /// [`PaymentHash`] has never been paid before.
-       pub fn pay_pubkey_with_id(
-               &self, pubkey: PublicKey, payment_preimage: PaymentPreimage, payment_id: PaymentId,
-               amount_msats: u64, final_cltv_expiry_delta: u32
-       ) -> Result<(), PaymentError> {
-               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
-               self.do_pay_pubkey(pubkey, payment_preimage, payment_hash, payment_id, amount_msats,
-                               final_cltv_expiry_delta)
-       }
+       /// [`Route`]: lightning::routing::router::Route
+       fn send_payment(
+               &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
+       ) -> Result<(), PaymentError>;
+}
 
-       fn do_pay_pubkey(
-               &self, pubkey: PublicKey, payment_preimage: PaymentPreimage, payment_hash: PaymentHash,
-               payment_id: PaymentId, amount_msats: u64, final_cltv_expiry_delta: u32
+impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> Payer for ChannelManager<M, T, ES, NS, SP, F, R, L>
+where
+               M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
+               T::Target: BroadcasterInterface,
+               ES::Target: EntropySource,
+               NS::Target: NodeSigner,
+               SP::Target: SignerProvider,
+               F::Target: FeeEstimator,
+               R::Target: Router,
+               L::Target: Logger,
+{
+       fn send_payment(
+               &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               payment_id: PaymentId, route_params: RouteParameters, retry_strategy: Retry
        ) -> Result<(), PaymentError> {
-               match self.payment_cache.lock().unwrap().entry(payment_hash) {
-                       hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
-                       hash_map::Entry::Vacant(entry) => entry.insert(PaymentAttempts::new()),
-               };
-
-               let route_params = RouteParameters {
-                       payment_params: PaymentParameters::for_keysend(pubkey, final_cltv_expiry_delta),
-                       final_value_msat: amount_msats,
-                       final_cltv_expiry_delta,
-               };
-
-               let send_payment = |route: &Route| {
-                       self.payer.send_spontaneous_payment(route, payment_preimage, payment_id)
-               };
-               self.pay_internal(&route_params, payment_hash, send_payment)
-                       .map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
+               self.send_payment_with_retry(payment_hash, payment_secret, payment_id, route_params, retry_strategy)
+                       .map_err(|e| PaymentError::Sending(e))
        }
+}
 
-       fn pay_internal<F: FnOnce(&Route) -> Result<(), PaymentSendFailure> + Copy>(
-               &self, params: &RouteParameters, payment_hash: PaymentHash, send_payment: F,
-       ) -> Result<(), PaymentError> {
-               #[cfg(feature = "std")] {
-                       if has_expired(params) {
-                               log_trace!(self.logger, "Invoice expired prior to send for payment {}", log_bytes!(payment_hash.0));
-                               return Err(PaymentError::Invoice("Invoice expired prior to send"));
-                       }
-               }
-
-               let payer = self.payer.node_id();
-               let first_hops = self.payer.first_hops();
-               let inflight_htlcs = self.payer.inflight_htlcs();
-               let route = self.router.find_route(
-                       &payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs
-               ).map_err(|e| PaymentError::Routing(e))?;
+#[cfg(test)]
+mod tests {
+       use super::*;
+       use crate::{InvoiceBuilder, Currency};
+       use bitcoin_hashes::sha256::Hash as Sha256;
+       use lightning::ln::PaymentPreimage;
+       use lightning::ln::functional_test_utils::*;
+       use secp256k1::{SecretKey, Secp256k1};
+       use std::collections::VecDeque;
+       use std::time::{SystemTime, Duration};
 
-               match send_payment(&route) {
-                       Ok(()) => Ok(()),
-                       Err(e) => match e {
-                               PaymentSendFailure::ParameterError(_) => Err(e),
-                               PaymentSendFailure::PathParameterError(_) => Err(e),
-                               PaymentSendFailure::DuplicatePayment => Err(e),
-                               PaymentSendFailure::AllFailedResendSafe(_) => {
-                                       let mut payment_cache = self.payment_cache.lock().unwrap();
-                                       let payment_attempts = payment_cache.get_mut(&payment_hash).unwrap();
-                                       payment_attempts.count += 1;
-                                       if self.retry.is_retryable_now(payment_attempts) {
-                                               core::mem::drop(payment_cache);
-                                               Ok(self.pay_internal(params, payment_hash, send_payment)?)
-                                       } else {
-                                               Err(e)
-                                       }
-                               },
-                               PaymentSendFailure::PartialFailure { failed_paths_retry, payment_id, .. } => {
-                                       if let Some(retry_data) = failed_paths_retry {
-                                               // Some paths were sent, even if we failed to send the full MPP value our
-                                               // recipient may misbehave and claim the funds, at which point we have to
-                                               // consider the payment sent, so return `Ok()` here, ignoring any retry
-                                               // errors.
-                                               let _ = self.retry_payment(payment_id, payment_hash, &retry_data);
-                                               Ok(())
-                                       } else {
-                                               // This may happen if we send a payment and some paths fail, but
-                                               // only due to a temporary monitor failure or the like, implying
-                                               // they're really in-flight, but we haven't sent the initial
-                                               // HTLC-Add messages yet.
-                                               Ok(())
-                                       }
-                               },
-                       },
-               }.map_err(|e| PaymentError::Sending(e))
+       struct TestPayer {
+               expectations: core::cell::RefCell<VecDeque<Amount>>,
        }
 
-       fn retry_payment(
-               &self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters
-       ) -> Result<(), ()> {
-               let attempts =
-                       *self.payment_cache.lock().unwrap().entry(payment_hash)
-                               .and_modify(|attempts| attempts.count += 1)
-                               .or_insert(PaymentAttempts {
-                                       count: 1,
-                                       first_attempted_at: T::now()
-                               });
-
-               if !self.retry.is_retryable_now(&attempts) {
-                       log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying ({})", log_bytes!(payment_hash.0), attempts);
-                       return Err(());
-               }
-
-               #[cfg(feature = "std")] {
-                       if has_expired(params) {
-                               log_trace!(self.logger, "Invoice expired for payment {}; not retrying ({:})", log_bytes!(payment_hash.0), attempts);
-                               return Err(());
+       impl TestPayer {
+               fn new() -> Self {
+                       Self {
+                               expectations: core::cell::RefCell::new(VecDeque::new()),
                        }
                }
 
-               let payer = self.payer.node_id();
-               let first_hops = self.payer.first_hops();
-               let inflight_htlcs = self.payer.inflight_htlcs();
-
-               let route = self.router.find_route(
-                       &payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs
-               );
-
-               if route.is_err() {
-                       log_trace!(self.logger, "Failed to find a route for payment {}; not retrying ({:})", log_bytes!(payment_hash.0), attempts);
-                       return Err(());
+               fn expect_send(self, value_msat: Amount) -> Self {
+                       self.expectations.borrow_mut().push_back(value_msat);
+                       self
                }
 
-               match self.payer.retry_payment(&route.as_ref().unwrap(), payment_id) {
-                       Ok(()) => Ok(()),
-                       Err(PaymentSendFailure::ParameterError(_)) |
-                       Err(PaymentSendFailure::PathParameterError(_)) => {
-                               log_trace!(self.logger, "Failed to retry for payment {} due to bogus route/payment data, not retrying.", log_bytes!(payment_hash.0));
-                               Err(())
-                       },
-                       Err(PaymentSendFailure::AllFailedResendSafe(_)) => {
-                               self.retry_payment(payment_id, payment_hash, params)
-                       },
-                       Err(PaymentSendFailure::DuplicatePayment) => {
-                               log_error!(self.logger, "Got a DuplicatePayment error when attempting to retry a payment, this shouldn't happen.");
-                               Err(())
+               fn check_value_msats(&self, actual_value_msats: Amount) {
+                       let expected_value_msats = self.expectations.borrow_mut().pop_front();
+                       if let Some(expected_value_msats) = expected_value_msats {
+                               assert_eq!(actual_value_msats, expected_value_msats);
+                       } else {
+                               panic!("Unexpected amount: {:?}", actual_value_msats);
                        }
-                       Err(PaymentSendFailure::PartialFailure { failed_paths_retry, .. }) => {
-                               if let Some(retry) = failed_paths_retry {
-                                       // Always return Ok for the same reason as noted in pay_internal.
-                                       let _ = self.retry_payment(payment_id, payment_hash, &retry);
-                               }
-                               Ok(())
-                       },
                }
        }
 
-       /// Removes the payment cached by the given payment hash.
-       ///
-       /// Should be called once a payment has failed or succeeded if not using [`InvoicePayer`] as an
-       /// [`EventHandler`]. Otherwise, calling this method is unnecessary.
-       pub fn remove_cached_payment(&self, payment_hash: &PaymentHash) {
-               self.payment_cache.lock().unwrap().remove(payment_hash);
-       }
-}
-
-fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
-       invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
-}
-
-#[cfg(feature = "std")]
-fn has_expired(route_params: &RouteParameters) -> bool {
-       if let Some(expiry_time) = route_params.payment_params.expiry_time {
-               Invoice::is_expired_from_epoch(&SystemTime::UNIX_EPOCH, Duration::from_secs(expiry_time))
-       } else { false }
-}
-
-impl<P: Deref, R: Deref, L: Deref, E: sealed::BaseEventHandler, T: Time>
-       InvoicePayerUsingTime<P, R, L, E, T>
-where
-       P::Target: Payer,
-       R::Target: Router,
-       L::Target: Logger,
-{
-       /// Returns a bool indicating whether the processed event should be forwarded to a user-provided
-       /// event handler.
-       fn handle_event_internal(&self, event: &Event) -> bool {
-               match event {
-                       Event::PaymentPathFailed {
-                               payment_id, payment_hash, payment_failed_permanently, path, short_channel_id, retry, ..
-                       } => {
-                               if let Some(short_channel_id) = short_channel_id {
-                                       let path = path.iter().collect::<Vec<_>>();
-                                       self.router.notify_payment_path_failed(&path, *short_channel_id)
-                               }
+       #[derive(Clone, Debug, PartialEq, Eq)]
+       struct Amount(u64); // msat
 
-                               if payment_id.is_none() {
-                                       log_trace!(self.logger, "Payment {} has no id; not retrying", log_bytes!(payment_hash.0));
-                               } else if *payment_failed_permanently {
-                                       log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0));
-                                       self.payer.abandon_payment(payment_id.unwrap());
-                               } else if retry.is_none() {
-                                       log_trace!(self.logger, "Payment {} missing retry params; not retrying", log_bytes!(payment_hash.0));
-                                       self.payer.abandon_payment(payment_id.unwrap());
-                               } else if self.retry_payment(payment_id.unwrap(), *payment_hash, retry.as_ref().unwrap()).is_ok() {
-                                       // We retried at least somewhat, don't provide the PaymentPathFailed event to the user.
-                                       return false;
-                               } else {
-                                       self.payer.abandon_payment(payment_id.unwrap());
-                               }
-                       },
-                       Event::PaymentFailed { payment_hash, .. } => {
-                               self.remove_cached_payment(&payment_hash);
-                       },
-                       Event::PaymentPathSuccessful { path, .. } => {
-                               let path = path.iter().collect::<Vec<_>>();
-                               self.router.notify_payment_path_successful(&path);
-                       },
-                       Event::PaymentSent { payment_hash, .. } => {
-                               let mut payment_cache = self.payment_cache.lock().unwrap();
-                               let attempts = payment_cache
-                                       .remove(payment_hash)
-                                       .map_or(1, |attempts| attempts.count + 1);
-                               log_trace!(self.logger, "Payment {} succeeded (attempts: {})", log_bytes!(payment_hash.0), attempts);
-                       },
-                       Event::ProbeSuccessful { payment_hash, path, .. } => {
-                               log_trace!(self.logger, "Probe payment {} of {}msat was successful", log_bytes!(payment_hash.0), path.last().unwrap().fee_msat);
-                               let path = path.iter().collect::<Vec<_>>();
-                               self.router.notify_payment_probe_successful(&path);
-                       },
-                       Event::ProbeFailed { payment_hash, path, short_channel_id, .. } => {
-                               if let Some(short_channel_id) = short_channel_id {
-                                       log_trace!(self.logger, "Probe payment {} of {}msat failed at channel {}", log_bytes!(payment_hash.0), path.last().unwrap().fee_msat, *short_channel_id);
-                                       let path = path.iter().collect::<Vec<_>>();
-                                       self.router.notify_payment_probe_failed(&path, *short_channel_id);
-                               }
-                       },
-                       _ => {},
+       impl Payer for TestPayer {
+               fn send_payment(
+                       &self, _payment_hash: PaymentHash, _payment_secret: &Option<PaymentSecret>,
+                       _payment_id: PaymentId, route_params: RouteParameters, _retry_strategy: Retry
+               ) -> Result<(), PaymentError> {
+                       self.check_value_msats(Amount(route_params.final_value_msat));
+                       Ok(())
                }
-
-               // Delegate to the decorated event handler unless the payment is retried.
-               true
        }
-}
 
-impl<P: Deref, R: Deref, L: Deref, E: EventHandler, T: Time>
-       EventHandler for InvoicePayerUsingTime<P, R, L, E, T>
-where
-       P::Target: Payer,
-       R::Target: Router,
-       L::Target: Logger,
-{
-       fn handle_event(&self, event: Event) {
-               let should_forward = self.handle_event_internal(&event);
-               if should_forward {
-                       self.event_handler.handle_event(event)
-               }
-       }
-}
+       impl Drop for TestPayer {
+               fn drop(&mut self) {
+                       if std::thread::panicking() {
+                               return;
+                       }
 
-impl<P: Deref, R: Deref, L: Deref, T: Time, F: Future, H: Fn(Event) -> F>
-       InvoicePayerUsingTime<P, R, L, H, T>
-where
-       P::Target: Payer,
-       R::Target: Router,
-       L::Target: Logger,
-{
-       /// Intercepts events required by the [`InvoicePayer`] and forwards them to the underlying event
-       /// handler, if necessary, to handle them asynchronously.
-       pub async fn handle_event_async(&self, event: Event) {
-               let should_forward = self.handle_event_internal(&event);
-               if should_forward {
-                       (self.event_handler)(event).await;
+                       if !self.expectations.borrow().is_empty() {
+                               panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
+                       }
                }
        }
-}
-
-#[cfg(test)]
-mod tests {
-       use super::*;
-       use crate::{InvoiceBuilder, Currency};
-       use crate::utils::create_invoice_from_channelmanager_and_duration_since_epoch;
-       use bitcoin_hashes::sha256::Hash as Sha256;
-       use lightning::ln::PaymentPreimage;
-       use lightning::ln::features::{ChannelFeatures, NodeFeatures};
-       use lightning::ln::functional_test_utils::*;
-       use lightning::ln::msgs::{ChannelMessageHandler, ErrorAction, LightningError};
-       use lightning::routing::gossip::{EffectiveCapacity, NodeId};
-       use lightning::routing::router::{InFlightHtlcs, PaymentParameters, Route, RouteHop, Router, ScorerAccountingForInFlightHtlcs};
-       use lightning::routing::scoring::{ChannelUsage, LockableScore, Score};
-       use lightning::util::test_utils::TestLogger;
-       use lightning::util::errors::APIError;
-       use lightning::util::events::{Event, EventsProvider, MessageSendEvent, MessageSendEventsProvider};
-       use secp256k1::{SecretKey, PublicKey, Secp256k1};
-       use std::cell::RefCell;
-       use std::collections::VecDeque;
-       use std::time::{SystemTime, Duration};
-       use crate::time_utils::tests::SinceEpoch;
-       use crate::DEFAULT_EXPIRY_TIME;
-
-       fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
-               let payment_hash = Sha256::hash(&payment_preimage.0);
-               let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
-
-               InvoiceBuilder::new(Currency::Bitcoin)
-                       .description("test".into())
-                       .payment_hash(payment_hash)
-                       .payment_secret(PaymentSecret([0; 32]))
-                       .duration_since_epoch(duration_since_epoch())
-                       .min_final_cltv_expiry_delta(144)
-                       .amount_milli_satoshis(128)
-                       .build_signed(|hash| {
-                               Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
-                       })
-                       .unwrap()
-       }
 
        fn duration_since_epoch() -> Duration {
                #[cfg(feature = "std")]
-                       let duration_since_epoch =
+               let duration_since_epoch =
                        SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
                #[cfg(not(feature = "std"))]
-                       let duration_since_epoch = Duration::from_secs(1234567);
+               let duration_since_epoch = Duration::from_secs(1234567);
                duration_since_epoch
        }
 
-       fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
+       fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
                let payment_hash = Sha256::hash(&payment_preimage.0);
                let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
 
@@ -792,1523 +289,65 @@ mod tests {
                        .payment_secret(PaymentSecret([0; 32]))
                        .duration_since_epoch(duration_since_epoch())
                        .min_final_cltv_expiry_delta(144)
+                       .amount_milli_satoshis(128)
                        .build_signed(|hash| {
                                Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
                        })
                        .unwrap()
        }
 
-       #[cfg(feature = "std")]
-       fn expired_invoice(payment_preimage: PaymentPreimage) -> Invoice {
+       fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
                let payment_hash = Sha256::hash(&payment_preimage.0);
                let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
-               let duration = duration_since_epoch()
-                       .checked_sub(Duration::from_secs(DEFAULT_EXPIRY_TIME * 2))
-                       .unwrap();
+
                InvoiceBuilder::new(Currency::Bitcoin)
                        .description("test".into())
                        .payment_hash(payment_hash)
                        .payment_secret(PaymentSecret([0; 32]))
-                       .duration_since_epoch(duration)
+                       .duration_since_epoch(duration_since_epoch())
                        .min_final_cltv_expiry_delta(144)
-                       .amount_milli_satoshis(128)
                        .build_signed(|hash| {
                                Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
                        })
-                       .unwrap()
-       }
-
-       fn pubkey() -> PublicKey {
-               PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap()
-       }
-
-       #[test]
-       fn pays_invoice_on_first_attempt() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(0));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               invoice_payer.handle_event(Event::PaymentSent {
-                       payment_id, payment_preimage, payment_hash, fee_paid_msat: None
-               });
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 1);
-       }
-
-       #[test]
-       fn pays_invoice_on_retry() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 2);
-
-               invoice_payer.handle_event(Event::PaymentSent {
-                       payment_id, payment_preimage, payment_hash, fee_paid_msat: None
-               });
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 2);
-       }
-
-       #[test]
-       fn pays_invoice_on_partial_failure() {
-               let event_handler = |_: Event| { panic!() };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let retry = TestRouter::retry_for_invoice(&invoice);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .fails_with_partial_failure(retry.clone(), OnAttempt(1), None)
-                       .fails_with_partial_failure(retry, OnAttempt(2), None)
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               assert!(invoice_payer.pay_invoice(&invoice).is_ok());
+               .unwrap()
        }
 
        #[test]
-       fn retries_payment_path_for_unknown_payment() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::OnRetry(final_value_msat / 2))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(PaymentId([1; 32]));
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 2);
-
-               invoice_payer.handle_event(Event::PaymentSent {
-                       payment_id, payment_preimage, payment_hash, fee_paid_msat: None
-               });
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 2);
-       }
-
-       #[test]
-       fn fails_paying_invoice_after_max_retry_counts() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
+       fn pays_invoice() {
+               let payment_id = PaymentId([42; 32]);
                let payment_preimage = PaymentPreimage([1; 32]);
                let invoice = invoice(payment_preimage);
                let final_value_msat = invoice.amount_milli_satoshis().unwrap();
 
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: true,
-                       path: TestRouter::path_for_value(final_value_msat),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 2);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat / 2),
-                       short_channel_id: None,
-                       retry: Some(RouteParameters {
-                               final_value_msat: final_value_msat / 2, ..TestRouter::retry_for_invoice(&invoice)
-                       }),
-               };
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 3);
-
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 3);
+               let payer = TestPayer::new().expect_send(Amount(final_value_msat));
+               pay_invoice_using_amount(&invoice, final_value_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
        }
 
-       #[cfg(feature = "std")]
        #[test]
-       fn fails_paying_invoice_after_max_retry_timeout() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
+       fn pays_zero_value_invoice() {
+               let payment_id = PaymentId([42; 32]);
                let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               type InvoicePayerUsingSinceEpoch <P, R, L, E> = InvoicePayerUsingTime::<P, R, L, E, SinceEpoch>;
-
-               let invoice_payer =
-                       InvoicePayerUsingSinceEpoch::new(&payer, &router, &logger, event_handler, Retry::Timeout(Duration::from_secs(120)));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: true,
-                       path: TestRouter::path_for_value(final_value_msat),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 2);
-
-               SinceEpoch::advance(Duration::from_secs(121));
+               let invoice = zero_value_invoice(payment_preimage);
+               let amt_msat = 10_000;
 
-               invoice_payer.handle_event(event.clone());
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 2);
+               let payer = TestPayer::new().expect_send(Amount(amt_msat));
+               pay_invoice_using_amount(&invoice, amt_msat, payment_id, Retry::Attempts(0), &payer).unwrap();
        }
 
        #[test]
-       fn fails_paying_invoice_with_missing_retry_params() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
+       fn fails_paying_zero_value_invoice_with_amount() {
+               let chanmon_cfgs = create_chanmon_cfgs(1);
+               let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
+               let node_chanmgrs = create_node_chanmgrs(1, &node_cfgs, &[None]);
+               let nodes = create_network(1, &node_cfgs, &node_chanmgrs);
 
                let payment_preimage = PaymentPreimage([1; 32]);
                let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: vec![],
-                       short_channel_id: None,
-                       retry: None,
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 1);
-       }
+               let amt_msat = 10_000;
 
-       // Expiration is checked only in an std environment
-       #[cfg(feature = "std")]
-       #[test]
-       fn fails_paying_invoice_after_expiration() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payer = TestPayer::new();
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = expired_invoice(payment_preimage);
-               if let PaymentError::Invoice(msg) = invoice_payer.pay_invoice(&invoice).unwrap_err() {
-                       assert_eq!(msg, "Invoice expired prior to send");
-               } else { panic!("Expected Invoice Error"); }
-       }
-
-       // Expiration is checked only in an std environment
-       #[cfg(feature = "std")]
-       #[test]
-       fn fails_retrying_invoice_after_expiration() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router,  &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let mut retry_data = TestRouter::retry_for_invoice(&invoice);
-               retry_data.payment_params.expiry_time = Some(SystemTime::now()
-                       .checked_sub(Duration::from_secs(2)).unwrap()
-                       .duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs());
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: vec![],
-                       short_channel_id: None,
-                       retry: Some(retry_data),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 1);
-       }
-
-       #[test]
-       fn fails_paying_invoice_after_retry_error() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .fails_on_attempt(2)
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat / 2),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 2);
-       }
-
-       #[test]
-       fn fails_paying_invoice_after_rejected_by_payee() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
-                       network_update: None,
-                       payment_failed_permanently: true,
-                       all_paths_failed: false,
-                       path: vec![],
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 1);
-       }
-
-       #[test]
-       fn fails_repaying_invoice_with_pending_payment() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(0));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-
-               // Cannot repay an invoice pending payment.
-               match invoice_payer.pay_invoice(&invoice) {
-                       Err(PaymentError::Invoice("payment pending")) => {},
-                       Err(_) => panic!("unexpected error"),
-                       Ok(_) => panic!("expected invoice error"),
-               }
-
-               // Can repay an invoice once cleared from cache.
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               invoice_payer.remove_cached_payment(&payment_hash);
-               assert!(invoice_payer.pay_invoice(&invoice).is_ok());
-
-               // Cannot retry paying an invoice if cleared from cache.
-               invoice_payer.remove_cached_payment(&payment_hash);
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: vec![],
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), true);
-       }
-
-       #[test]
-       fn fails_paying_invoice_with_routing_errors() {
-               let payer = TestPayer::new();
-               let router = FailingRouter {};
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, |_: Event| {}, Retry::Attempts(0));
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               match invoice_payer.pay_invoice(&invoice) {
-                       Err(PaymentError::Routing(_)) => {},
-                       Err(_) => panic!("unexpected error"),
-                       Ok(_) => panic!("expected routing error"),
-               }
-       }
-
-       #[test]
-       fn fails_paying_invoice_with_sending_errors() {
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .fails_on_attempt(1)
-                       .expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, |_: Event| {}, Retry::Attempts(0));
-
-               match invoice_payer.pay_invoice(&invoice) {
-                       Err(PaymentError::Sending(_)) => {},
-                       Err(_) => panic!("unexpected error"),
-                       Ok(_) => panic!("expected sending error"),
-               }
-       }
-
-       #[test]
-       fn pays_zero_value_invoice_using_amount() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = zero_value_invoice(payment_preimage);
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               let final_value_msat = 100;
-
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(0));
-
-               let payment_id =
-                       Some(invoice_payer.pay_zero_value_invoice(&invoice, final_value_msat).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               invoice_payer.handle_event(Event::PaymentSent {
-                       payment_id, payment_preimage, payment_hash, fee_paid_msat: None
-               });
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 1);
-       }
-
-       #[test]
-       fn fails_paying_zero_value_invoice_with_amount() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payer = TestPayer::new();
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router,  &logger, event_handler, Retry::Attempts(0));
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-
-               // Cannot repay an invoice pending payment.
-               match invoice_payer.pay_zero_value_invoice(&invoice, 100) {
+               match pay_zero_value_invoice(&invoice, amt_msat, Retry::Attempts(0), &nodes[0].node) {
                        Err(PaymentError::Invoice("amount unexpected")) => {},
-                       Err(_) => panic!("unexpected error"),
-                       Ok(_) => panic!("expected invoice error"),
-               }
-       }
-
-       #[test]
-       fn pays_pubkey_with_amount() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let pubkey = pubkey();
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
-               let final_value_msat = 100;
-               let final_cltv_expiry_delta = 42;
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::Spontaneous(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat));
-               let router = TestRouter::new(TestScorer::new());
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_pubkey(
-                               pubkey, payment_preimage, final_value_msat, final_cltv_expiry_delta
-                       ).unwrap());
-               assert_eq!(*payer.attempts.borrow(), 1);
-
-               let retry = RouteParameters {
-                       payment_params: PaymentParameters::for_keysend(pubkey, final_cltv_expiry_delta),
-                       final_value_msat,
-                       final_cltv_expiry_delta,
-               };
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: vec![],
-                       short_channel_id: None,
-                       retry: Some(retry),
-               };
-               invoice_payer.handle_event(event);
-               assert_eq!(*event_handled.borrow(), false);
-               assert_eq!(*payer.attempts.borrow(), 2);
-
-               invoice_payer.handle_event(Event::PaymentSent {
-                       payment_id, payment_preimage, payment_hash, fee_paid_msat: None
-               });
-               assert_eq!(*event_handled.borrow(), true);
-               assert_eq!(*payer.attempts.borrow(), 2);
-       }
-
-       #[test]
-       fn scores_failed_channel() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-               let path = TestRouter::path_for_value(final_value_msat);
-               let short_channel_id = Some(path[0].short_channel_id);
-
-               // Expect that scorer is given short_channel_id upon handling the event.
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2));
-               let scorer = TestScorer::new().expect(TestResult::PaymentFailure {
-                       path: path.clone(), short_channel_id: path[0].short_channel_id,
-               });
-               let router = TestRouter::new(scorer);
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
-               let event = Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path,
-                       short_channel_id,
-                       retry: Some(TestRouter::retry_for_invoice(&invoice)),
-               };
-               invoice_payer.handle_event(event);
-       }
-
-       #[test]
-       fn scores_successful_channels() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let invoice = invoice(payment_preimage);
-               let payment_hash = Some(PaymentHash(invoice.payment_hash().clone().into_inner()));
-               let final_value_msat = invoice.amount_milli_satoshis().unwrap();
-               let route = TestRouter::route_for_value(final_value_msat);
-
-               // Expect that scorer is given short_channel_id upon handling the event.
-               let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
-               let scorer = TestScorer::new()
-                       .expect(TestResult::PaymentSuccess { path: route.paths[0].clone() })
-                       .expect(TestResult::PaymentSuccess { path: route.paths[1].clone() });
-               let router = TestRouter::new(scorer);
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               let payment_id = invoice_payer.pay_invoice(&invoice).unwrap();
-               let event = Event::PaymentPathSuccessful {
-                       payment_id, payment_hash, path: route.paths[0].clone()
-               };
-               invoice_payer.handle_event(event);
-               let event = Event::PaymentPathSuccessful {
-                       payment_id, payment_hash, path: route.paths[1].clone()
-               };
-               invoice_payer.handle_event(event);
-       }
-
-       #[test]
-       fn considers_inflight_htlcs_between_invoice_payments() {
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let payment_invoice = invoice(payment_preimage);
-               let final_value_msat = payment_invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::ForInvoice(final_value_msat));
-               let scorer = TestScorer::new()
-                       // 1st invoice, 1st path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 84, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 94, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // 1st invoice, 2nd path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 74, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // 2nd invoice, 1st path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 64, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 84, inflight_htlc_msat: 84, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 94, inflight_htlc_msat: 94, effective_capacity: EffectiveCapacity::Unknown } )
-                       // 2nd invoice, 2nd path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 64, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 74, inflight_htlc_msat: 74, effective_capacity: EffectiveCapacity::Unknown } );
-               let router = TestRouter::new(scorer);
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(0));
-
-               // Make first invoice payment.
-               invoice_payer.pay_invoice(&payment_invoice).unwrap();
-
-               // Let's pay a second invoice that will be using the same path. This should trigger the
-               // assertions that expect `ChannelUsage` values of the first invoice payment that is still
-               // in-flight.
-               let payment_preimage_2 = PaymentPreimage([2; 32]);
-               let payment_invoice_2 = invoice(payment_preimage_2);
-               invoice_payer.pay_invoice(&payment_invoice_2).unwrap();
-       }
-
-       #[test]
-       fn considers_inflight_htlcs_between_retries() {
-               // First, let's just send a payment through, but only make sure one of the path completes
-               let event_handled = core::cell::RefCell::new(false);
-               let event_handler = |_: Event| { *event_handled.borrow_mut() = true; };
-
-               let payment_preimage = PaymentPreimage([1; 32]);
-               let payment_invoice = invoice(payment_preimage);
-               let payment_hash = PaymentHash(payment_invoice.payment_hash().clone().into_inner());
-               let final_value_msat = payment_invoice.amount_milli_satoshis().unwrap();
-
-               let payer = TestPayer::new()
-                       .expect_send(Amount::ForInvoice(final_value_msat))
-                       .expect_send(Amount::OnRetry(final_value_msat / 2))
-                       .expect_send(Amount::OnRetry(final_value_msat / 4));
-               let final_value_msat = payment_invoice.amount_milli_satoshis().unwrap();
-               let scorer = TestScorer::new()
-                       // 1st invoice, 1st path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 84, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 94, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // 1st invoice, 2nd path
-                       .expect_usage(ChannelUsage { amount_msat: 64, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 74, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // Retry 1, 1st path
-                       .expect_usage(ChannelUsage { amount_msat: 32, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 52, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 62, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // Retry 1, 2nd path
-                       .expect_usage(ChannelUsage { amount_msat: 32, inflight_htlc_msat: 64, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 42, inflight_htlc_msat: 64 + 10, effective_capacity: EffectiveCapacity::Unknown } )
-                       // Retry 2, 1st path
-                       .expect_usage(ChannelUsage { amount_msat: 16, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 36, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 46, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown } )
-                       // Retry 2, 2nd path
-                       .expect_usage(ChannelUsage { amount_msat: 16, inflight_htlc_msat: 64 + 32, effective_capacity: EffectiveCapacity::Unknown } )
-                       .expect_usage(ChannelUsage { amount_msat: 26, inflight_htlc_msat: 74 + 32 + 10, effective_capacity: EffectiveCapacity::Unknown } );
-               let router = TestRouter::new(scorer);
-               let logger = TestLogger::new();
-               let invoice_payer =
-                       InvoicePayer::new(&payer, &router, &logger, event_handler, Retry::Attempts(2));
-
-               // Fail 1st path, leave 2nd path inflight
-               let payment_id = Some(invoice_payer.pay_invoice(&payment_invoice).unwrap());
-               invoice_payer.payer.fail_path(&TestRouter::path_for_value(final_value_msat));
-               invoice_payer.handle_event(Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat),
-                       short_channel_id: None,
-                       retry: Some(TestRouter::retry_for_invoice(&payment_invoice)),
-               });
-
-               // Fails again the 1st path of our retry
-               invoice_payer.payer.fail_path(&TestRouter::path_for_value(final_value_msat / 2));
-               invoice_payer.handle_event(Event::PaymentPathFailed {
-                       payment_id,
-                       payment_hash,
-                       network_update: None,
-                       payment_failed_permanently: false,
-                       all_paths_failed: false,
-                       path: TestRouter::path_for_value(final_value_msat / 2),
-                       short_channel_id: None,
-                       retry: Some(RouteParameters {
-                               final_value_msat: final_value_msat / 4,
-                               ..TestRouter::retry_for_invoice(&payment_invoice)
-                       }),
-               });
-       }
-
-       struct TestRouter {
-               scorer: RefCell<TestScorer>,
-       }
-
-       impl TestRouter {
-               fn new(scorer: TestScorer) -> Self {
-                       TestRouter { scorer: RefCell::new(scorer) }
-               }
-
-               fn route_for_value(final_value_msat: u64) -> Route {
-                       Route {
-                               paths: vec![
-                                       vec![
-                                               RouteHop {
-                                                       pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
-                                                       channel_features: ChannelFeatures::empty(),
-                                                       node_features: NodeFeatures::empty(),
-                                                       short_channel_id: 0,
-                                                       fee_msat: 10,
-                                                       cltv_expiry_delta: 0
-                                               },
-                                               RouteHop {
-                                                       pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
-                                                       channel_features: ChannelFeatures::empty(),
-                                                       node_features: NodeFeatures::empty(),
-                                                       short_channel_id: 1,
-                                                       fee_msat: 20,
-                                                       cltv_expiry_delta: 0
-                                               },
-                                               RouteHop {
-                                                       pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
-                                                       channel_features: ChannelFeatures::empty(),
-                                                       node_features: NodeFeatures::empty(),
-                                                       short_channel_id: 2,
-                                                       fee_msat: final_value_msat / 2,
-                                                       cltv_expiry_delta: 0
-                                               },
-                                       ],
-                                       vec![
-                                               RouteHop {
-                                                       pubkey: PublicKey::from_slice(&hex::decode("029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255").unwrap()[..]).unwrap(),
-                                                       channel_features: ChannelFeatures::empty(),
-                                                       node_features: NodeFeatures::empty(),
-                                                       short_channel_id: 3,
-                                                       fee_msat: 10,
-                                                       cltv_expiry_delta: 144
-                                               },
-                                               RouteHop {
-                                                       pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
-                                                       channel_features: ChannelFeatures::empty(),
-                                                       node_features: NodeFeatures::empty(),
-                                                       short_channel_id: 4,
-                                                       fee_msat: final_value_msat / 2,
-                                                       cltv_expiry_delta: 144
-                                               }
-                                       ],
-                               ],
-                               payment_params: None,
-                       }
-               }
-
-               fn path_for_value(final_value_msat: u64) -> Vec<RouteHop> {
-                       TestRouter::route_for_value(final_value_msat).paths[0].clone()
-               }
-
-               fn retry_for_invoice(invoice: &Invoice) -> RouteParameters {
-                       let mut payment_params = PaymentParameters::from_node_id(
-                                       invoice.recover_payee_pub_key(), invoice.min_final_cltv_expiry_delta() as u32)
-                               .with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
-                               .with_route_hints(invoice.route_hints());
-                       if let Some(features) = invoice.features() {
-                               payment_params = payment_params.with_features(features.clone());
-                       }
-                       let final_value_msat = invoice.amount_milli_satoshis().unwrap() / 2;
-                       RouteParameters {
-                               payment_params,
-                               final_value_msat,
-                               final_cltv_expiry_delta: invoice.min_final_cltv_expiry_delta() as u32,
-                       }
-               }
-       }
-
-       impl Router for TestRouter {
-               fn find_route(
-                       &self, payer: &PublicKey, route_params: &RouteParameters,
-                       _first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
-               ) -> Result<Route, LightningError> {
-                       // Simulate calling the Scorer just as you would in find_route
-                       let route = Self::route_for_value(route_params.final_value_msat);
-                       let locked_scorer = self.scorer.lock();
-                       let scorer = ScorerAccountingForInFlightHtlcs::new(locked_scorer, inflight_htlcs);
-                       for path in route.paths {
-                               let mut aggregate_msat = 0u64;
-                               for (idx, hop) in path.iter().rev().enumerate() {
-                                       aggregate_msat += hop.fee_msat;
-                                       let usage = ChannelUsage {
-                                               amount_msat: aggregate_msat,
-                                               inflight_htlc_msat: 0,
-                                               effective_capacity: EffectiveCapacity::Unknown,
-                                       };
-
-                                       // Since the path is reversed, the last element in our iteration is the first
-                                       // hop.
-                                       if idx == path.len() - 1 {
-                                               scorer.channel_penalty_msat(hop.short_channel_id, &NodeId::from_pubkey(payer), &NodeId::from_pubkey(&hop.pubkey), usage);
-                                       } else {
-                                               scorer.channel_penalty_msat(hop.short_channel_id, &NodeId::from_pubkey(&path[idx + 1].pubkey), &NodeId::from_pubkey(&hop.pubkey), usage);
-                                       }
-                               }
-                       }
-
-                       Ok(Route {
-                               payment_params: Some(route_params.payment_params.clone()), ..Self::route_for_value(route_params.final_value_msat)
-                       })
-               }
-
-               fn notify_payment_path_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-                       self.scorer.lock().payment_path_failed(path, short_channel_id);
+                       _ => panic!()
                }
-
-               fn notify_payment_path_successful(&self, path: &[&RouteHop]) {
-                       self.scorer.lock().payment_path_successful(path);
-               }
-
-               fn notify_payment_probe_successful(&self, path: &[&RouteHop]) {
-                       self.scorer.lock().probe_successful(path);
-               }
-
-               fn notify_payment_probe_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-                       self.scorer.lock().probe_failed(path, short_channel_id);
-               }
-       }
-
-       struct FailingRouter;
-
-       impl Router for FailingRouter {
-               fn find_route(
-                       &self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-                       _inflight_htlcs: &InFlightHtlcs,
-               ) -> Result<Route, LightningError> {
-                       Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError })
-               }
-
-               fn notify_payment_path_failed(&self, _path: &[&RouteHop], _short_channel_id: u64) {}
-
-               fn notify_payment_path_successful(&self, _path: &[&RouteHop]) {}
-
-               fn notify_payment_probe_successful(&self, _path: &[&RouteHop]) {}
-
-               fn notify_payment_probe_failed(&self, _path: &[&RouteHop], _short_channel_id: u64) {}
-       }
-
-       struct TestScorer {
-               event_expectations: Option<VecDeque<TestResult>>,
-               scorer_expectations: RefCell<Option<VecDeque<ChannelUsage>>>,
-       }
-
-       #[derive(Debug)]
-       enum TestResult {
-               PaymentFailure { path: Vec<RouteHop>, short_channel_id: u64 },
-               PaymentSuccess { path: Vec<RouteHop> },
-       }
-
-       impl TestScorer {
-               fn new() -> Self {
-                       Self {
-                               event_expectations: None,
-                               scorer_expectations: RefCell::new(None),
-                       }
-               }
-
-               fn expect(mut self, expectation: TestResult) -> Self {
-                       self.event_expectations.get_or_insert_with(|| VecDeque::new()).push_back(expectation);
-                       self
-               }
-
-               fn expect_usage(self, expectation: ChannelUsage) -> Self {
-                       self.scorer_expectations.borrow_mut().get_or_insert_with(|| VecDeque::new()).push_back(expectation);
-                       self
-               }
-       }
-
-       #[cfg(c_bindings)]
-       impl lightning::util::ser::Writeable for TestScorer {
-               fn write<W: lightning::util::ser::Writer>(&self, _: &mut W) -> Result<(), lightning::io::Error> { unreachable!(); }
-       }
-
-       impl Score for TestScorer {
-               fn channel_penalty_msat(
-                       &self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId, usage: ChannelUsage
-               ) -> u64 {
-                       if let Some(scorer_expectations) = self.scorer_expectations.borrow_mut().as_mut() {
-                               match scorer_expectations.pop_front() {
-                                       Some(expectation) => {
-                                               assert_eq!(expectation.amount_msat, usage.amount_msat);
-                                               assert_eq!(expectation.inflight_htlc_msat, usage.inflight_htlc_msat);
-                                       },
-                                       None => {},
-                               }
-                       }
-                       0
-               }
-
-               fn payment_path_failed(&mut self, actual_path: &[&RouteHop], actual_short_channel_id: u64) {
-                       if let Some(expectations) = &mut self.event_expectations {
-                               match expectations.pop_front() {
-                                       Some(TestResult::PaymentFailure { path, short_channel_id }) => {
-                                               assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
-                                               assert_eq!(actual_short_channel_id, short_channel_id);
-                                       },
-                                       Some(TestResult::PaymentSuccess { path }) => {
-                                               panic!("Unexpected successful payment path: {:?}", path)
-                                       },
-                                       None => panic!("Unexpected notify_payment_path_failed call: {:?}", actual_path),
-                               }
-                       }
-               }
-
-               fn payment_path_successful(&mut self, actual_path: &[&RouteHop]) {
-                       if let Some(expectations) = &mut self.event_expectations {
-                               match expectations.pop_front() {
-                                       Some(TestResult::PaymentFailure { path, .. }) => {
-                                               panic!("Unexpected payment path failure: {:?}", path)
-                                       },
-                                       Some(TestResult::PaymentSuccess { path }) => {
-                                               assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
-                                       },
-                                       None => panic!("Unexpected notify_payment_path_successful call: {:?}", actual_path),
-                               }
-                       }
-               }
-
-               fn probe_failed(&mut self, actual_path: &[&RouteHop], _: u64) {
-                       if let Some(expectations) = &mut self.event_expectations {
-                               match expectations.pop_front() {
-                                       Some(TestResult::PaymentFailure { path, .. }) => {
-                                               panic!("Unexpected failed payment path: {:?}", path)
-                                       },
-                                       Some(TestResult::PaymentSuccess { path }) => {
-                                               panic!("Unexpected successful payment path: {:?}", path)
-                                       },
-                                       None => panic!("Unexpected notify_payment_path_failed call: {:?}", actual_path),
-                               }
-                       }
-               }
-               fn probe_successful(&mut self, actual_path: &[&RouteHop]) {
-                       if let Some(expectations) = &mut self.event_expectations {
-                               match expectations.pop_front() {
-                                       Some(TestResult::PaymentFailure { path, .. }) => {
-                                               panic!("Unexpected payment path failure: {:?}", path)
-                                       },
-                                       Some(TestResult::PaymentSuccess { path }) => {
-                                               panic!("Unexpected successful payment path: {:?}", path)
-                                       },
-                                       None => panic!("Unexpected notify_payment_path_successful call: {:?}", actual_path),
-                               }
-                       }
-               }
-       }
-
-       impl Drop for TestScorer {
-               fn drop(&mut self) {
-                       if std::thread::panicking() {
-                               return;
-                       }
-
-                       if let Some(event_expectations) = &self.event_expectations {
-                               if !event_expectations.is_empty() {
-                                       panic!("Unsatisfied event expectations: {:?}", event_expectations);
-                               }
-                       }
-
-                       if let Some(scorer_expectations) = self.scorer_expectations.borrow().as_ref() {
-                               if !scorer_expectations.is_empty() {
-                                       panic!("Unsatisfied scorer expectations: {:?}", scorer_expectations)
-                               }
-                       }
-               }
-       }
-
-       struct TestPayer {
-               expectations: core::cell::RefCell<VecDeque<Amount>>,
-               attempts: core::cell::RefCell<usize>,
-               failing_on_attempt: core::cell::RefCell<HashMap<usize, PaymentSendFailure>>,
-               inflight_htlcs_paths: core::cell::RefCell<Vec<Vec<RouteHop>>>,
-       }
-
-       #[derive(Clone, Debug, PartialEq, Eq)]
-       enum Amount {
-               ForInvoice(u64),
-               Spontaneous(u64),
-               OnRetry(u64),
-       }
-
-       struct OnAttempt(usize);
-
-       impl TestPayer {
-               fn new() -> Self {
-                       Self {
-                               expectations: core::cell::RefCell::new(VecDeque::new()),
-                               attempts: core::cell::RefCell::new(0),
-                               failing_on_attempt: core::cell::RefCell::new(HashMap::new()),
-                               inflight_htlcs_paths: core::cell::RefCell::new(Vec::new()),
-                       }
-               }
-
-               fn expect_send(self, value_msat: Amount) -> Self {
-                       self.expectations.borrow_mut().push_back(value_msat);
-                       self
-               }
-
-               fn fails_on_attempt(self, attempt: usize) -> Self {
-                       let failure = PaymentSendFailure::ParameterError(APIError::MonitorUpdateInProgress);
-                       self.fails_with(failure, OnAttempt(attempt))
-               }
-
-               fn fails_with_partial_failure(self, retry: RouteParameters, attempt: OnAttempt, results: Option<Vec<Result<(), APIError>>>) -> Self {
-                       self.fails_with(PaymentSendFailure::PartialFailure {
-                               results: results.unwrap_or(vec![]),
-                               failed_paths_retry: Some(retry),
-                               payment_id: PaymentId([1; 32]),
-                       }, attempt)
-               }
-
-               fn fails_with(self, failure: PaymentSendFailure, attempt: OnAttempt) -> Self {
-                       self.failing_on_attempt.borrow_mut().insert(attempt.0, failure);
-                       self
-               }
-
-               fn check_attempts(&self) -> Result<(), PaymentSendFailure> {
-                       let mut attempts = self.attempts.borrow_mut();
-                       *attempts += 1;
-
-                       match self.failing_on_attempt.borrow_mut().remove(&*attempts) {
-                               Some(failure) => Err(failure),
-                               None => Ok(())
-                       }
-               }
-
-               fn check_value_msats(&self, actual_value_msats: Amount) {
-                       let expected_value_msats = self.expectations.borrow_mut().pop_front();
-                       if let Some(expected_value_msats) = expected_value_msats {
-                               assert_eq!(actual_value_msats, expected_value_msats);
-                       } else {
-                               panic!("Unexpected amount: {:?}", actual_value_msats);
-                       }
-               }
-
-               fn track_inflight_htlcs(&self, route: &Route) {
-                       for path in &route.paths {
-                               self.inflight_htlcs_paths.borrow_mut().push(path.clone());
-                       }
-               }
-
-               fn fail_path(&self, path: &Vec<RouteHop>) {
-                       let path_idx = self.inflight_htlcs_paths.borrow().iter().position(|p| p == path);
-
-                       if let Some(idx) = path_idx {
-                               self.inflight_htlcs_paths.borrow_mut().swap_remove(idx);
-                       }
-               }
-       }
-
-       impl Drop for TestPayer {
-               fn drop(&mut self) {
-                       if std::thread::panicking() {
-                               return;
-                       }
-
-                       if !self.expectations.borrow().is_empty() {
-                               panic!("Unsatisfied payment expectations: {:?}", self.expectations.borrow());
-                       }
-               }
-       }
-
-       impl Payer for TestPayer {
-               fn node_id(&self) -> PublicKey {
-                       let secp_ctx = Secp256k1::new();
-                       PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
-               }
-
-               fn first_hops(&self) -> Vec<ChannelDetails> {
-                       Vec::new()
-               }
-
-               fn send_payment(
-                       &self, route: &Route, _payment_hash: PaymentHash,
-                       _payment_secret: &Option<PaymentSecret>, _payment_id: PaymentId,
-               ) -> Result<(), PaymentSendFailure> {
-                       self.check_value_msats(Amount::ForInvoice(route.get_total_amount()));
-                       self.track_inflight_htlcs(route);
-                       self.check_attempts()
-               }
-
-               fn send_spontaneous_payment(
-                       &self, route: &Route, _payment_preimage: PaymentPreimage, _payment_id: PaymentId,
-               ) -> Result<(), PaymentSendFailure> {
-                       self.check_value_msats(Amount::Spontaneous(route.get_total_amount()));
-                       self.check_attempts()
-               }
-
-               fn retry_payment(
-                       &self, route: &Route, _payment_id: PaymentId
-               ) -> Result<(), PaymentSendFailure> {
-                       self.check_value_msats(Amount::OnRetry(route.get_total_amount()));
-                       self.track_inflight_htlcs(route);
-                       self.check_attempts()
-               }
-
-               fn abandon_payment(&self, _payment_id: PaymentId) { }
-
-               fn inflight_htlcs(&self) -> InFlightHtlcs {
-                       let mut inflight_htlcs = InFlightHtlcs::new();
-                       for path in self.inflight_htlcs_paths.clone().into_inner() {
-                               inflight_htlcs.process_path(&path, self.node_id());
-                       }
-                       inflight_htlcs
-               }
-       }
-
-       // *** Full Featured Functional Tests with a Real ChannelManager ***
-       struct ManualRouter(RefCell<VecDeque<Result<Route, LightningError>>>);
-
-       impl Router for ManualRouter {
-               fn find_route(
-                       &self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-                       _inflight_htlcs: &InFlightHtlcs
-               ) -> Result<Route, LightningError> {
-                       self.0.borrow_mut().pop_front().unwrap()
-               }
-
-               fn notify_payment_path_failed(&self, _path: &[&RouteHop], _short_channel_id: u64) {}
-
-               fn notify_payment_path_successful(&self, _path: &[&RouteHop]) {}
-
-               fn notify_payment_probe_successful(&self, _path: &[&RouteHop]) {}
-
-               fn notify_payment_probe_failed(&self, _path: &[&RouteHop], _short_channel_id: u64) {}
-       }
-       impl ManualRouter {
-               fn expect_find_route(&self, result: Result<Route, LightningError>) {
-                       self.0.borrow_mut().push_back(result);
-               }
-       }
-       impl Drop for ManualRouter {
-               fn drop(&mut self) {
-                       if std::thread::panicking() {
-                               return;
-                       }
-                       assert!(self.0.borrow_mut().is_empty());
-               }
-       }
-
-       #[test]
-       fn retry_multi_path_single_failed_payment() {
-               // Tests that we can/will retry after a single path of an MPP payment failed immediately
-               let chanmon_cfgs = create_chanmon_cfgs(2);
-               let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-               let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
-               let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
-               create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
-               create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
-               let chans = nodes[0].node.list_usable_channels();
-               let mut route = Route {
-                       paths: vec![
-                               vec![RouteHop {
-                                       pubkey: nodes[1].node.get_our_node_id(),
-                                       node_features: nodes[1].node.node_features(),
-                                       short_channel_id: chans[0].short_channel_id.unwrap(),
-                                       channel_features: nodes[1].node.channel_features(),
-                                       fee_msat: 10_000,
-                                       cltv_expiry_delta: 100,
-                               }],
-                               vec![RouteHop {
-                                       pubkey: nodes[1].node.get_our_node_id(),
-                                       node_features: nodes[1].node.node_features(),
-                                       short_channel_id: chans[1].short_channel_id.unwrap(),
-                                       channel_features: nodes[1].node.channel_features(),
-                                       fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
-                                       cltv_expiry_delta: 100,
-                               }],
-                       ],
-                       payment_params: Some(PaymentParameters::from_node_id(nodes[1].node.get_our_node_id(), 100)),
-               };
-               let router = ManualRouter(RefCell::new(VecDeque::new()));
-               router.expect_find_route(Ok(route.clone()));
-               // On retry, split the payment across both channels.
-               route.paths[0][0].fee_msat = 50_000_001;
-               route.paths[1][0].fee_msat = 50_000_000;
-               router.expect_find_route(Ok(route.clone()));
-
-               let event_handler = |_: Event| { panic!(); };
-               let invoice_payer = InvoicePayer::new(nodes[0].node, &router, nodes[0].logger, event_handler, Retry::Attempts(1));
-
-               assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
-                       &nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-                       Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
-                       .is_ok());
-               let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
-               assert_eq!(htlc_msgs.len(), 2);
-               check_added_monitors!(nodes[0], 2);
-       }
-
-       #[test]
-       fn immediate_retry_on_failure() {
-               // Tests that we can/will retry immediately after a failure
-               let chanmon_cfgs = create_chanmon_cfgs(2);
-               let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-               let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
-               let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
-               create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
-               create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
-               let chans = nodes[0].node.list_usable_channels();
-               let mut route = Route {
-                       paths: vec![
-                               vec![RouteHop {
-                                       pubkey: nodes[1].node.get_our_node_id(),
-                                       node_features: nodes[1].node.node_features(),
-                                       short_channel_id: chans[0].short_channel_id.unwrap(),
-                                       channel_features: nodes[1].node.channel_features(),
-                                       fee_msat: 100_000_001, // Our default max-HTLC-value is 10% of the channel value, which this is one more than
-                                       cltv_expiry_delta: 100,
-                               }],
-                       ],
-                       payment_params: Some(PaymentParameters::from_node_id(nodes[1].node.get_our_node_id(), 100)),
-               };
-               let router = ManualRouter(RefCell::new(VecDeque::new()));
-               router.expect_find_route(Ok(route.clone()));
-               // On retry, split the payment across both channels.
-               route.paths.push(route.paths[0].clone());
-               route.paths[0][0].short_channel_id = chans[1].short_channel_id.unwrap();
-               route.paths[0][0].fee_msat = 50_000_000;
-               route.paths[1][0].fee_msat = 50_000_001;
-               router.expect_find_route(Ok(route.clone()));
-
-               let event_handler = |_: Event| { panic!(); };
-               let invoice_payer = InvoicePayer::new(nodes[0].node, &router, nodes[0].logger, event_handler, Retry::Attempts(1));
-
-               assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
-                       &nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-                       Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
-                       .is_ok());
-               let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
-               assert_eq!(htlc_msgs.len(), 2);
-               check_added_monitors!(nodes[0], 2);
-       }
-
-       #[test]
-       fn no_extra_retries_on_back_to_back_fail() {
-               // In a previous release, we had a race where we may exceed the payment retry count if we
-               // get two failures in a row with the second having `all_paths_failed` set.
-               // Generally, when we give up trying to retry a payment, we don't know for sure what the
-               // current state of the ChannelManager event queue is. Specifically, we cannot be sure that
-               // there are not multiple additional `PaymentPathFailed` or even `PaymentSent` events
-               // pending which we will see later. Thus, when we previously removed the retry tracking map
-               // entry after a `all_paths_failed` `PaymentPathFailed` event, we may have dropped the
-               // retry entry even though more events for the same payment were still pending. This led to
-               // us retrying a payment again even though we'd already given up on it.
-               //
-               // We now have a separate event - `PaymentFailed` which indicates no HTLCs remain and which
-               // is used to remove the payment retry counter entries instead. This tests for the specific
-               // excess-retry case while also testing `PaymentFailed` generation.
-
-               let chanmon_cfgs = create_chanmon_cfgs(3);
-               let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
-               let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
-               let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
-
-               let chan_1_scid = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 0).0.contents.short_channel_id;
-               let chan_2_scid = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 10_000_000, 0).0.contents.short_channel_id;
-
-               let mut route = Route {
-                       paths: vec![
-                               vec![RouteHop {
-                                       pubkey: nodes[1].node.get_our_node_id(),
-                                       node_features: nodes[1].node.node_features(),
-                                       short_channel_id: chan_1_scid,
-                                       channel_features: nodes[1].node.channel_features(),
-                                       fee_msat: 0,
-                                       cltv_expiry_delta: 100,
-                               }, RouteHop {
-                                       pubkey: nodes[2].node.get_our_node_id(),
-                                       node_features: nodes[2].node.node_features(),
-                                       short_channel_id: chan_2_scid,
-                                       channel_features: nodes[2].node.channel_features(),
-                                       fee_msat: 100_000_000,
-                                       cltv_expiry_delta: 100,
-                               }],
-                               vec![RouteHop {
-                                       pubkey: nodes[1].node.get_our_node_id(),
-                                       node_features: nodes[1].node.node_features(),
-                                       short_channel_id: chan_1_scid,
-                                       channel_features: nodes[2].node.channel_features(),
-                                       fee_msat: 0,
-                                       cltv_expiry_delta: 100,
-                               }, RouteHop {
-                                       pubkey: nodes[2].node.get_our_node_id(),
-                                       node_features: nodes[2].node.node_features(),
-                                       short_channel_id: chan_2_scid,
-                                       channel_features: nodes[2].node.channel_features(),
-                                       fee_msat: 100_000_000,
-                                       cltv_expiry_delta: 100,
-                               }]
-                       ],
-                       payment_params: Some(PaymentParameters::from_node_id(nodes[2].node.get_our_node_id(), 100)),
-               };
-               let router = ManualRouter(RefCell::new(VecDeque::new()));
-               router.expect_find_route(Ok(route.clone()));
-               // On retry, we'll only be asked for one path
-               route.paths.remove(1);
-               router.expect_find_route(Ok(route.clone()));
-
-               let expected_events: RefCell<VecDeque<&dyn Fn(Event)>> = RefCell::new(VecDeque::new());
-               let event_handler = |event: Event| {
-                       let event_checker = expected_events.borrow_mut().pop_front().unwrap();
-                       event_checker(event);
-               };
-               let invoice_payer = InvoicePayer::new(nodes[0].node, &router, nodes[0].logger, event_handler, Retry::Attempts(1));
-
-               assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
-                       &nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-                       Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
-                       .is_ok());
-               let htlc_updates = SendEvent::from_node(&nodes[0]);
-               check_added_monitors!(nodes[0], 1);
-               assert_eq!(htlc_updates.msgs.len(), 1);
-
-               nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &htlc_updates.msgs[0]);
-               nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &htlc_updates.commitment_msg);
-               check_added_monitors!(nodes[1], 1);
-               let (bs_first_raa, bs_first_cs) = get_revoke_commit_msgs!(nodes[1], nodes[0].node.get_our_node_id());
-
-               nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_first_raa);
-               check_added_monitors!(nodes[0], 1);
-               let second_htlc_updates = SendEvent::from_node(&nodes[0]);
-
-               nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_first_cs);
-               check_added_monitors!(nodes[0], 1);
-               let as_first_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
-
-               nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &second_htlc_updates.msgs[0]);
-               nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &second_htlc_updates.commitment_msg);
-               check_added_monitors!(nodes[1], 1);
-               let bs_second_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
-
-               nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_first_raa);
-               check_added_monitors!(nodes[1], 1);
-               let bs_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
-
-               nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_second_raa);
-               check_added_monitors!(nodes[0], 1);
-
-               nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_fail_update.update_fail_htlcs[0]);
-               nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_fail_update.commitment_signed);
-               check_added_monitors!(nodes[0], 1);
-               let (as_second_raa, as_third_cs) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
-
-               nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_second_raa);
-               check_added_monitors!(nodes[1], 1);
-               let bs_second_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
-
-               nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_third_cs);
-               check_added_monitors!(nodes[1], 1);
-               let bs_third_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
-
-               nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_second_fail_update.update_fail_htlcs[0]);
-               nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_second_fail_update.commitment_signed);
-               check_added_monitors!(nodes[0], 1);
-
-               nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_third_raa);
-               check_added_monitors!(nodes[0], 1);
-               let (as_third_raa, as_fourth_cs) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
-
-               nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_third_raa);
-               check_added_monitors!(nodes[1], 1);
-               nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_fourth_cs);
-               check_added_monitors!(nodes[1], 1);
-               let bs_fourth_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
-
-               nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_fourth_raa);
-               check_added_monitors!(nodes[0], 1);
-
-               // At this point A has sent two HTLCs which both failed due to lack of fee. It now has two
-               // pending `PaymentPathFailed` events, one with `all_paths_failed` unset, and the second
-               // with it set. The first event will use up the only retry we are allowed, with the second
-               // `PaymentPathFailed` being passed up to the user (us, in this case). Previously, we'd
-               // treated this as "HTLC complete" and dropped the retry counter, causing us to retry again
-               // if the final HTLC failed.
-               expected_events.borrow_mut().push_back(&|ev: Event| {
-                       if let Event::PaymentPathFailed { payment_failed_permanently, all_paths_failed, .. } = ev {
-                               assert!(!payment_failed_permanently);
-                               assert!(all_paths_failed);
-                       } else { panic!("Unexpected event"); }
-               });
-               nodes[0].node.process_pending_events(&invoice_payer);
-               assert!(expected_events.borrow().is_empty());
-
-               let retry_htlc_updates = SendEvent::from_node(&nodes[0]);
-               check_added_monitors!(nodes[0], 1);
-
-               nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &retry_htlc_updates.msgs[0]);
-               commitment_signed_dance!(nodes[1], nodes[0], &retry_htlc_updates.commitment_msg, false, true);
-               let bs_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
-               nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_fail_update.update_fail_htlcs[0]);
-               commitment_signed_dance!(nodes[0], nodes[1], &bs_fail_update.commitment_signed, false, true);
-
-               expected_events.borrow_mut().push_back(&|ev: Event| {
-                       if let Event::PaymentPathFailed { payment_failed_permanently, all_paths_failed, .. } = ev {
-                               assert!(!payment_failed_permanently);
-                               assert!(all_paths_failed);
-                       } else { panic!("Unexpected event"); }
-               });
-               expected_events.borrow_mut().push_back(&|ev: Event| {
-                       if let Event::PaymentFailed { .. } = ev {
-                       } else { panic!("Unexpected event"); }
-               });
-               nodes[0].node.process_pending_events(&invoice_payer);
-               assert!(expected_events.borrow().is_empty());
        }
 }
index 3d19d3a9f691734759cac1ed5e0eb48caed4f540..83f72e461455d3e3d06001121b7fa2bf8c6414f5 100644 (file)
@@ -1,7 +1,6 @@
 //! Convenient utilities to create an invoice.
 
 use crate::{CreationError, Currency, Invoice, InvoiceBuilder, SignOrCreationError};
-use crate::payment::Payer;
 
 use crate::{prelude::*, Description, InvoiceDescription, Sha256};
 use bech32::ToBase32;
@@ -9,12 +8,12 @@ use bitcoin_hashes::Hash;
 use lightning::chain;
 use lightning::chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use lightning::chain::keysinterface::{Recipient, NodeSigner, SignerProvider, EntropySource};
-use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, PaymentId, PaymentSendFailure, MIN_FINAL_CLTV_EXPIRY_DELTA};
+use lightning::ln::{PaymentHash, PaymentSecret};
+use lightning::ln::channelmanager::{ChannelDetails, ChannelManager, MIN_FINAL_CLTV_EXPIRY_DELTA};
 use lightning::ln::channelmanager::{PhantomRouteHints, MIN_CLTV_EXPIRY_DELTA};
 use lightning::ln::inbound_payment::{create, create_from_hash, ExpandedKey};
 use lightning::routing::gossip::RoutingFees;
-use lightning::routing::router::{InFlightHtlcs, Route, RouteHint, RouteHintHop, Router};
+use lightning::routing::router::{RouteHint, RouteHintHop, Router};
 use lightning::util::logger::Logger;
 use secp256k1::PublicKey;
 use core::ops::Deref;
@@ -634,51 +633,6 @@ fn filter_channels<L: Deref>(
                .collect::<Vec<RouteHint>>()
 }
 
-impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> Payer for ChannelManager<M, T, ES, NS, SP, F, R, L>
-where
-       M::Target: chain::Watch<<SP::Target as SignerProvider>::Signer>,
-       T::Target: BroadcasterInterface,
-       ES::Target: EntropySource,
-       NS::Target: NodeSigner,
-       SP::Target: SignerProvider,
-       F::Target: FeeEstimator,
-       R::Target: Router,
-       L::Target: Logger,
-{
-       fn node_id(&self) -> PublicKey {
-               self.get_our_node_id()
-       }
-
-       fn first_hops(&self) -> Vec<ChannelDetails> {
-               self.list_usable_channels()
-       }
-
-       fn send_payment(
-               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
-               payment_id: PaymentId
-       ) -> Result<(), PaymentSendFailure> {
-               self.send_payment(route, payment_hash, payment_secret, payment_id)
-       }
-
-       fn send_spontaneous_payment(
-               &self, route: &Route, payment_preimage: PaymentPreimage, payment_id: PaymentId,
-       ) -> Result<(), PaymentSendFailure> {
-               self.send_spontaneous_payment(route, Some(payment_preimage), payment_id).map(|_| ())
-       }
-
-       fn retry_payment(
-               &self, route: &Route, payment_id: PaymentId
-       ) -> Result<(), PaymentSendFailure> {
-               self.retry_payment(route, payment_id)
-       }
-
-       fn abandon_payment(&self, payment_id: PaymentId) {
-               self.abandon_payment(payment_id)
-       }
-
-       fn inflight_htlcs(&self) -> InFlightHtlcs { self.compute_inflight_htlcs() }
-}
-
 #[cfg(test)]
 mod test {
        use core::time::Duration;