_ Git - rust-lightning/blob - lightning/src/offers/refund.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for refunds.
  11 //!
  12 //! A [`Refund`] is an "offer for money" and is typically constructed by a merchant and presented
  13 //! directly to the customer. The recipient responds with an `Invoice` to be paid.
  14 //!
  15 //! This is an [`InvoiceRequest`] produced *not* in response to an [`Offer`].
  16 //!
  17 //! [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
  18 //! [`Offer`]: crate::offers::offer::Offer
  19 //!
  20 //! ```ignore
  21 //! extern crate bitcoin;
  22 //! extern crate core;
  23 //! extern crate lightning;
  24 //!
  25 //! use core::convert::TryFrom;
  26 //! use core::time::Duration;
  27 //!
  28 //! use bitcoin::network::constants::Network;
  29 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  30 //! use lightning::offers::parse::ParseError;
  31 //! use lightning::offers::refund::{Refund, RefundBuilder};
  32 //! use lightning::util::ser::{Readable, Writeable};
  33 //!
  34 //! # use lightning::onion_message::BlindedPath;
  35 //! # #[cfg(feature = "std")]
  36 //! # use std::time::SystemTime;
  37 //! #
  38 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  39 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  40 //! #
  41 //! # #[cfg(feature = "std")]
  42 //! # fn build() -> Result<(), ParseError> {
  43 //! let secp_ctx = Secp256k1::new();
  44 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  45 //! let pubkey = PublicKey::from(keys);
  46 //!
  47 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  48 //! let refund = RefundBuilder::new("coffee, large".to_string(), vec![1; 32], pubkey, 20_000)?
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .chain(Network::Bitcoin)
  54 //!     .payer_note("refund for order #12345".to_string())
  55 //!     .build()?;
  56 //!
  57 //! // Encode as a bech32 string for use in a QR code.
  58 //! let encoded_refund = refund.to_string();
  59 //!
  60 //! // Parse from a bech32 string after scanning from a QR code.
  61 //! let refund = encoded_refund.parse::<Refund>()?;
  62 //!
  63 //! // Encode refund as raw bytes.
  64 //! let mut bytes = Vec::new();
  65 //! refund.write(&mut bytes).unwrap();
  66 //!
  67 //! // Decode raw bytes into an refund.
  68 //! let refund = Refund::try_from(bytes)?;
  69 //! # Ok(())
  70 //! # }
  71 //! ```
  72
  73 use bitcoin::blockdata::constants::ChainHash;
  74 use bitcoin::network::constants::Network;
  75 use bitcoin::secp256k1::PublicKey;
  76 use core::convert::TryFrom;
  77 use core::str::FromStr;
  78 use core::time::Duration;
  79 use crate::io;
  80 use crate::ln::features::InvoiceRequestFeatures;
  81 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  82 use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
  83 use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef};
  84 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
  85 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  86 use crate::onion_message::BlindedPath;
  87 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
  88 use crate::util::string::PrintableString;
  89
  90 use crate::prelude::*;
  91
  92 #[cfg(feature = "std")]
  93 use std::time::SystemTime;
  94
  95 /// Builds a [`Refund`] for the "offer for money" flow.
  96 ///
  97 /// See [module-level documentation] for usage.
  98 ///
  99 /// [module-level documentation]: self
 100 pub struct RefundBuilder {
 101         refund: RefundContents,
 102 }
 103
 104 impl RefundBuilder {
 105         /// Creates a new builder for a refund using the [`Refund::payer_id`] for signing invoices. Use
 106         /// a different pubkey per refund to avoid correlating refunds.
 107         ///
 108         /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and
 109         /// [`Refund::amount_msats`].
 110         pub fn new(
 111                 description: String, metadata: Vec<u8>, payer_id: PublicKey, amount_msats: u64
 112         ) -> Result<Self, SemanticError> {
 113                 if amount_msats > MAX_VALUE_MSAT {
 114                         return Err(SemanticError::InvalidAmount);
 115                 }
 116
 117                 let refund = RefundContents {
 118                         payer: PayerContents(metadata), metadata: None, description, absolute_expiry: None,
 119                         issuer: None, paths: None, chain: None, amount_msats,
 120                         features: InvoiceRequestFeatures::empty(), payer_id, payer_note: None,
 121                 };
 122
 123                 Ok(RefundBuilder { refund })
 124         }
 125
 126         /// Sets the [`Refund::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 127         /// already passed is valid and can be checked for using [`Refund::is_expired`].
 128         ///
 129         /// Successive calls to this method will override the previous setting.
 130         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 131                 self.refund.absolute_expiry = Some(absolute_expiry);
 132                 self
 133         }
 134
 135         /// Sets the [`Refund::issuer`].
 136         ///
 137         /// Successive calls to this method will override the previous setting.
 138         pub fn issuer(mut self, issuer: String) -> Self {
 139                 self.refund.issuer = Some(issuer);
 140                 self
 141         }
 142
 143         /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
 144         /// by private channels or if [`Refund::payer_id`] is not a public node id.
 145         ///
 146         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 147         /// adding duplicate paths.
 148         pub fn path(mut self, path: BlindedPath) -> Self {
 149                 self.refund.paths.get_or_insert_with(Vec::new).push(path);
 150                 self
 151         }
 152
 153         /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
 154         /// called, [`Network::Bitcoin`] is assumed.
 155         ///
 156         /// Successive calls to this method will override the previous setting.
 157         pub fn chain(mut self, network: Network) -> Self {
 158                 self.refund.chain = Some(ChainHash::using_genesis_block(network));
 159                 self
 160         }
 161
 162         /// Sets the [`Refund::payer_note`].
 163         ///
 164         /// Successive calls to this method will override the previous setting.
 165         pub fn payer_note(mut self, payer_note: String) -> Self {
 166                 self.refund.payer_note = Some(payer_note);
 167                 self
 168         }
 169
 170         /// Builds a [`Refund`] after checking for valid semantics.
 171         pub fn build(mut self) -> Result<Refund, SemanticError> {
 172                 if self.refund.chain() == self.refund.implied_chain() {
 173                         self.refund.chain = None;
 174                 }
 175
 176                 let mut bytes = Vec::new();
 177                 self.refund.write(&mut bytes).unwrap();
 178
 179                 Ok(Refund {
 180                         bytes,
 181                         contents: self.refund,
 182                 })
 183         }
 184 }
 185
 186 /// A `Refund` is a request to send an `Invoice` without a preceding [`Offer`].
 187 ///
 188 /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to
 189 /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a
 190 /// bitcoin ATM.
 191 ///
 192 /// [`Offer`]: crate::offers::offer::Offer
 193 #[derive(Clone, Debug)]
 194 pub struct Refund {
 195         bytes: Vec<u8>,
 196         contents: RefundContents,
 197 }
 198
 199 /// The contents of a [`Refund`], which may be shared with an `Invoice`.
 200 #[derive(Clone, Debug)]
 201 struct RefundContents {
 202         payer: PayerContents,
 203         // offer fields
 204         metadata: Option<Vec<u8>>,
 205         description: String,
 206         absolute_expiry: Option<Duration>,
 207         issuer: Option<String>,
 208         paths: Option<Vec<BlindedPath>>,
 209         // invoice_request fields
 210         chain: Option<ChainHash>,
 211         amount_msats: u64,
 212         features: InvoiceRequestFeatures,
 213         payer_id: PublicKey,
 214         payer_note: Option<String>,
 215 }
 216
 217 impl Refund {
 218         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 219         /// but with the caveat that it has not been verified in any way.
 220         pub fn description(&self) -> PrintableString {
 221                 PrintableString(&self.contents.description)
 222         }
 223
 224         /// Duration since the Unix epoch when an invoice should no longer be sent.
 225         ///
 226         /// If `None`, the refund does not expire.
 227         pub fn absolute_expiry(&self) -> Option<Duration> {
 228                 self.contents.absolute_expiry
 229         }
 230
 231         /// Whether the refund has expired.
 232         #[cfg(feature = "std")]
 233         pub fn is_expired(&self) -> bool {
 234                 match self.absolute_expiry() {
 235                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 236                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 237                                 Err(_) => false,
 238                         },
 239                         None => false,
 240                 }
 241         }
 242
 243         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 244         /// displayed to the user but with the caveat that it has not been verified in any way.
 245         pub fn issuer(&self) -> Option<PrintableString> {
 246                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 247         }
 248
 249         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 250         /// privacy by obfuscating its node id.
 251         pub fn paths(&self) -> &[BlindedPath] {
 252                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 253         }
 254
 255         /// An unpredictable series of bytes, typically containing information about the derivation of
 256         /// [`payer_id`].
 257         ///
 258         /// [`payer_id`]: Self::payer_id
 259         pub fn metadata(&self) -> &[u8] {
 260                 &self.contents.payer.0
 261         }
 262
 263         /// A chain that the refund is valid for.
 264         pub fn chain(&self) -> ChainHash {
 265                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 266         }
 267
 268         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 269         ///
 270         /// [`chain`]: Self::chain
 271         pub fn amount_msats(&self) -> u64 {
 272                 self.contents.amount_msats
 273         }
 274
 275         /// Features pertaining to requesting an invoice.
 276         pub fn features(&self) -> &InvoiceRequestFeatures {
 277                 &self.contents.features
 278         }
 279
 280         /// A possibly transient pubkey used to sign the refund.
 281         pub fn payer_id(&self) -> PublicKey {
 282                 self.contents.payer_id
 283         }
 284
 285         /// Payer provided note to include in the invoice.
 286         pub fn payer_note(&self) -> Option<PrintableString> {
 287                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 288         }
 289
 290         #[cfg(test)]
 291         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 292                 self.contents.as_tlv_stream()
 293         }
 294 }
 295
 296 impl AsRef<[u8]> for Refund {
 297         fn as_ref(&self) -> &[u8] {
 298                 &self.bytes
 299         }
 300 }
 301
 302 impl RefundContents {
 303         fn chain(&self) -> ChainHash {
 304                 self.chain.unwrap_or_else(|| self.implied_chain())
 305         }
 306
 307         pub fn implied_chain(&self) -> ChainHash {
 308                 ChainHash::using_genesis_block(Network::Bitcoin)
 309         }
 310
 311         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 312                 let payer = PayerTlvStreamRef {
 313                         metadata: Some(&self.payer.0),
 314                 };
 315
 316                 let offer = OfferTlvStreamRef {
 317                         chains: None,
 318                         metadata: self.metadata.as_ref(),
 319                         currency: None,
 320                         amount: None,
 321                         description: Some(&self.description),
 322                         features: None,
 323                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 324                         paths: self.paths.as_ref(),
 325                         issuer: self.issuer.as_ref(),
 326                         quantity_max: None,
 327                         node_id: None,
 328                 };
 329
 330                 let features = {
 331                         if self.features == InvoiceRequestFeatures::empty() { None }
 332                         else { Some(&self.features) }
 333                 };
 334
 335                 let invoice_request = InvoiceRequestTlvStreamRef {
 336                         chain: self.chain.as_ref(),
 337                         amount: Some(self.amount_msats),
 338                         features,
 339                         quantity: None,
 340                         payer_id: Some(&self.payer_id),
 341                         payer_note: self.payer_note.as_ref(),
 342                 };
 343
 344                 (payer, offer, invoice_request)
 345         }
 346 }
 347
 348 impl Writeable for Refund {
 349         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 350                 WithoutLength(&self.bytes).write(writer)
 351         }
 352 }
 353
 354 impl Writeable for RefundContents {
 355         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 356                 self.as_tlv_stream().write(writer)
 357         }
 358 }
 359
 360 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 361
 362 type RefundTlvStreamRef<'a> = (
 363         PayerTlvStreamRef<'a>,
 364         OfferTlvStreamRef<'a>,
 365         InvoiceRequestTlvStreamRef<'a>,
 366 );
 367
 368 impl SeekReadable for RefundTlvStream {
 369         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 370                 let payer = SeekReadable::read(r)?;
 371                 let offer = SeekReadable::read(r)?;
 372                 let invoice_request = SeekReadable::read(r)?;
 373
 374                 Ok((payer, offer, invoice_request))
 375         }
 376 }
 377
 378 impl Bech32Encode for Refund {
 379         const BECH32_HRP: &'static str = "lnr";
 380 }
 381
 382 impl FromStr for Refund {
 383         type Err = ParseError;
 384
 385         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 386                 Refund::from_bech32_str(s)
 387         }
 388 }
 389
 390 impl TryFrom<Vec<u8>> for Refund {
 391         type Error = ParseError;
 392
 393         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 394                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 395                 let ParsedMessage { bytes, tlv_stream } = refund;
 396                 let contents = RefundContents::try_from(tlv_stream)?;
 397
 398                 Ok(Refund { bytes, contents })
 399         }
 400 }
 401
 402 impl TryFrom<RefundTlvStream> for RefundContents {
 403         type Error = SemanticError;
 404
 405         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 406                 let (
 407                         PayerTlvStream { metadata: payer_metadata },
 408                         OfferTlvStream {
 409                                 chains, metadata, currency, amount: offer_amount, description,
 410                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 411                         },
 412                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 413                 ) = tlv_stream;
 414
 415                 let payer = match payer_metadata {
 416                         None => return Err(SemanticError::MissingPayerMetadata),
 417                         Some(metadata) => PayerContents(metadata),
 418                 };
 419
 420                 if chains.is_some() {
 421                         return Err(SemanticError::UnexpectedChain);
 422                 }
 423
 424                 if currency.is_some() || offer_amount.is_some() {
 425                         return Err(SemanticError::UnexpectedAmount);
 426                 }
 427
 428                 let description = match description {
 429                         None => return Err(SemanticError::MissingDescription),
 430                         Some(description) => description,
 431                 };
 432
 433                 if offer_features.is_some() {
 434                         return Err(SemanticError::UnexpectedFeatures);
 435                 }
 436
 437                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 438
 439                 if quantity_max.is_some() {
 440                         return Err(SemanticError::UnexpectedQuantity);
 441                 }
 442
 443                 if node_id.is_some() {
 444                         return Err(SemanticError::UnexpectedSigningPubkey);
 445                 }
 446
 447                 let amount_msats = match amount {
 448                         None => return Err(SemanticError::MissingAmount),
 449                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 450                                 return Err(SemanticError::InvalidAmount);
 451                         },
 452                         Some(amount_msats) => amount_msats,
 453                 };
 454
 455                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 456
 457                 // TODO: Check why this isn't in the spec.
 458                 if quantity.is_some() {
 459                         return Err(SemanticError::UnexpectedQuantity);
 460                 }
 461
 462                 let payer_id = match payer_id {
 463                         None => return Err(SemanticError::MissingPayerId),
 464                         Some(payer_id) => payer_id,
 465                 };
 466
 467                 // TODO: Should metadata be included?
 468                 Ok(RefundContents {
 469                         payer, metadata, description, absolute_expiry, issuer, paths, chain, amount_msats,
 470                         features, payer_id, payer_note,
 471                 })
 472         }
 473 }
 474
 475 impl core::fmt::Display for Refund {
 476         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 477                 self.fmt_bech32_str(f)
 478         }
 479 }
 480
 481 #[cfg(test)]
 482 mod tests {
 483         use super::{Refund, RefundBuilder};
 484
 485         use bitcoin::blockdata::constants::ChainHash;
 486         use bitcoin::network::constants::Network;
 487         use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 488         use core::convert::TryFrom;
 489         use core::time::Duration;
 490         use crate::ln::features::InvoiceRequestFeatures;
 491         use crate::ln::msgs::MAX_VALUE_MSAT;
 492         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 493         use crate::offers::offer::OfferTlvStreamRef;
 494         use crate::offers::parse::SemanticError;
 495         use crate::offers::payer::PayerTlvStreamRef;
 496         use crate::onion_message::{BlindedHop, BlindedPath};
 497         use crate::util::ser::Writeable;
 498         use crate::util::string::PrintableString;
 499
 500         fn payer_pubkey() -> PublicKey {
 501                 let secp_ctx = Secp256k1::new();
 502                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()).public_key()
 503         }
 504
 505         fn pubkey(byte: u8) -> PublicKey {
 506                 let secp_ctx = Secp256k1::new();
 507                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 508         }
 509
 510         fn privkey(byte: u8) -> SecretKey {
 511                 SecretKey::from_slice(&[byte; 32]).unwrap()
 512         }
 513
 514         #[test]
 515         fn builds_refund_with_defaults() {
 516                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 517                         .build().unwrap();
 518
 519                 let mut buffer = Vec::new();
 520                 refund.write(&mut buffer).unwrap();
 521
 522                 assert_eq!(refund.bytes, buffer.as_slice());
 523                 assert_eq!(refund.metadata(), &[1; 32]);
 524                 assert_eq!(refund.description(), PrintableString("foo"));
 525                 assert_eq!(refund.absolute_expiry(), None);
 526                 #[cfg(feature = "std")]
 527                 assert!(!refund.is_expired());
 528                 assert_eq!(refund.paths(), &[]);
 529                 assert_eq!(refund.issuer(), None);
 530                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 531                 assert_eq!(refund.amount_msats(), 1000);
 532                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 533                 assert_eq!(refund.payer_id(), payer_pubkey());
 534                 assert_eq!(refund.payer_note(), None);
 535
 536                 assert_eq!(
 537                         refund.as_tlv_stream(),
 538                         (
 539                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 540                                 OfferTlvStreamRef {
 541                                         chains: None,
 542                                         metadata: None,
 543                                         currency: None,
 544                                         amount: None,
 545                                         description: Some(&String::from("foo")),
 546                                         features: None,
 547                                         absolute_expiry: None,
 548                                         paths: None,
 549                                         issuer: None,
 550                                         quantity_max: None,
 551                                         node_id: None,
 552                                 },
 553                                 InvoiceRequestTlvStreamRef {
 554                                         chain: None,
 555                                         amount: Some(1000),
 556                                         features: None,
 557                                         quantity: None,
 558                                         payer_id: Some(&payer_pubkey()),
 559                                         payer_note: None,
 560                                 },
 561                         ),
 562                 );
 563
 564                 if let Err(e) = Refund::try_from(buffer) {
 565                         panic!("error parsing refund: {:?}", e);
 566                 }
 567         }
 568
 569         #[test]
 570         fn fails_building_refund_with_invalid_amount() {
 571                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 572                         Ok(_) => panic!("expected error"),
 573                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 574                 }
 575         }
 576
 577         #[test]
 578         fn builds_refund_with_absolute_expiry() {
 579                 let future_expiry = Duration::from_secs(u64::max_value());
 580                 let past_expiry = Duration::from_secs(0);
 581
 582                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 583                         .absolute_expiry(future_expiry)
 584                         .build()
 585                         .unwrap();
 586                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 587                 #[cfg(feature = "std")]
 588                 assert!(!refund.is_expired());
 589                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 590                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 591
 592                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 593                         .absolute_expiry(future_expiry)
 594                         .absolute_expiry(past_expiry)
 595                         .build()
 596                         .unwrap();
 597                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 598                 #[cfg(feature = "std")]
 599                 assert!(refund.is_expired());
 600                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 601                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 602         }
 603
 604         #[test]
 605         fn builds_refund_with_paths() {
 606                 let paths = vec![
 607                         BlindedPath {
 608                                 introduction_node_id: pubkey(40),
 609                                 blinding_point: pubkey(41),
 610                                 blinded_hops: vec![
 611                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 612                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 613                                 ],
 614                         },
 615                         BlindedPath {
 616                                 introduction_node_id: pubkey(40),
 617                                 blinding_point: pubkey(41),
 618                                 blinded_hops: vec![
 619                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 620                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 621                                 ],
 622                         },
 623                 ];
 624
 625                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 626                         .path(paths[0].clone())
 627                         .path(paths[1].clone())
 628                         .build()
 629                         .unwrap();
 630                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 631                 assert_eq!(refund.paths(), paths.as_slice());
 632                 assert_eq!(refund.payer_id(), pubkey(42));
 633                 assert_ne!(pubkey(42), pubkey(44));
 634                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 635                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 636         }
 637
 638         #[test]
 639         fn builds_refund_with_issuer() {
 640                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 641                         .issuer("bar".into())
 642                         .build()
 643                         .unwrap();
 644                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 645                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 646                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 647
 648                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 649                         .issuer("bar".into())
 650                         .issuer("baz".into())
 651                         .build()
 652                         .unwrap();
 653                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 654                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 655                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 656         }
 657
 658         #[test]
 659         fn builds_refund_with_chain() {
 660                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 661                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 662
 663                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 664                         .chain(Network::Bitcoin)
 665                         .build().unwrap();
 666                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 667                 assert_eq!(refund.chain(), mainnet);
 668                 assert_eq!(tlv_stream.chain, None);
 669
 670                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 671                         .chain(Network::Testnet)
 672                         .build().unwrap();
 673                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 674                 assert_eq!(refund.chain(), testnet);
 675                 assert_eq!(tlv_stream.chain, Some(&testnet));
 676
 677                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 678                         .chain(Network::Regtest)
 679                         .chain(Network::Testnet)
 680                         .build().unwrap();
 681                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 682                 assert_eq!(refund.chain(), testnet);
 683                 assert_eq!(tlv_stream.chain, Some(&testnet));
 684         }
 685
 686         #[test]
 687         fn builds_refund_with_payer_note() {
 688                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 689                         .payer_note("bar".into())
 690                         .build().unwrap();
 691                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 692                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 693                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 694
 695                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 696                         .payer_note("bar".into())
 697                         .payer_note("baz".into())
 698                         .build().unwrap();
 699                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 700                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 701                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 702         }
 703 }