Invoice request building tests
[rust-lightning] / lightning / src / offers / offer.rs
index d64091155d78aef81709959efa5cf67704b35431..d890ab3f642cfb14fffe70f843b3086f8688fdcb 100644 (file)
@@ -8,14 +8,78 @@
 // licenses.
 
 //! Data structures and encoding for `offer` messages.
+//!
+//! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
+//! published as a QR code to be scanned by a customer. The customer uses the offer to request an
+//! invoice from the merchant to be paid.
+//!
+//! ```ignore
+//! extern crate bitcoin;
+//! extern crate core;
+//! extern crate lightning;
+//!
+//! use core::convert::TryFrom;
+//! use core::num::NonZeroU64;
+//! use core::time::Duration;
+//!
+//! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
+//! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
+//! use lightning::offers::parse::ParseError;
+//! use lightning::util::ser::{Readable, Writeable};
+//!
+//! # use lightning::onion_message::BlindedPath;
+//! # #[cfg(feature = "std")]
+//! # use std::time::SystemTime;
+//! #
+//! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
+//! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
+//! #
+//! # #[cfg(feature = "std")]
+//! # fn build() -> Result<(), ParseError> {
+//! let secp_ctx = Secp256k1::new();
+//! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+//! let pubkey = PublicKey::from(keys);
+//!
+//! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
+//! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
+//!     .amount_msats(20_000)
+//!     .supported_quantity(Quantity::Unbounded)
+//!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
+//!     .issuer("Foo Bar".to_string())
+//!     .path(create_blinded_path())
+//!     .path(create_another_blinded_path())
+//!     .build()?;
+//!
+//! // Encode as a bech32 string for use in a QR code.
+//! let encoded_offer = offer.to_string();
+//!
+//! // Parse from a bech32 string after scanning from a QR code.
+//! let offer = encoded_offer.parse::<Offer>()?;
+//!
+//! // Encode offer as raw bytes.
+//! let mut bytes = Vec::new();
+//! offer.write(&mut bytes).unwrap();
+//!
+//! // Decode raw bytes into an offer.
+//! let offer = Offer::try_from(bytes)?;
+//! # Ok(())
+//! # }
+//! ```
 
 use bitcoin::blockdata::constants::ChainHash;
 use bitcoin::network::constants::Network;
 use bitcoin::secp256k1::PublicKey;
+use core::convert::TryFrom;
 use core::num::NonZeroU64;
+use core::str::FromStr;
 use core::time::Duration;
+use crate::io;
 use crate::ln::features::OfferFeatures;
+use crate::ln::msgs::MAX_VALUE_MSAT;
+use crate::offers::invoice_request::InvoiceRequestBuilder;
+use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
 use crate::onion_message::BlindedPath;
+use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
 use crate::util::string::PrintableString;
 
 use crate::prelude::*;
@@ -23,9 +87,144 @@ use crate::prelude::*;
 #[cfg(feature = "std")]
 use std::time::SystemTime;
 
+/// Builds an [`Offer`] for the "offer to be paid" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [module-level documentation]: self
+pub struct OfferBuilder {
+       offer: OfferContents,
+}
+
+impl OfferBuilder {
+       /// Creates a new builder for an offer setting the [`Offer::description`] and using the
+       /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
+       /// while the offer is valid.
+       ///
+       /// Use a different pubkey per offer to avoid correlating offers.
+       pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
+               let offer = OfferContents {
+                       chains: None, metadata: None, amount: None, description,
+                       features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
+                       supported_quantity: Quantity::one(), signing_pubkey: Some(signing_pubkey),
+               };
+               OfferBuilder { offer }
+       }
+
+       /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
+       /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
+       ///
+       /// See [`Offer::chains`] on how this relates to the payment currency.
+       ///
+       /// Successive calls to this method will add another chain hash.
+       pub fn chain(mut self, network: Network) -> Self {
+               let chains = self.offer.chains.get_or_insert_with(Vec::new);
+               let chain = ChainHash::using_genesis_block(network);
+               if !chains.contains(&chain) {
+                       chains.push(chain);
+               }
+
+               self
+       }
+
+       /// Sets the [`Offer::metadata`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       pub fn metadata(mut self, metadata: Vec<u8>) -> Self {
+               self.offer.metadata = Some(metadata);
+               self
+       }
+
+       /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       pub fn amount_msats(self, amount_msats: u64) -> Self {
+               self.amount(Amount::Bitcoin { amount_msats })
+       }
+
+       /// Sets the [`Offer::amount`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       fn amount(mut self, amount: Amount) -> Self {
+               self.offer.amount = Some(amount);
+               self
+       }
+
+       /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
+       /// already passed is valid and can be checked for using [`Offer::is_expired`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
+               self.offer.absolute_expiry = Some(absolute_expiry);
+               self
+       }
+
+       /// Sets the [`Offer::issuer`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       pub fn issuer(mut self, issuer: String) -> Self {
+               self.offer.issuer = Some(issuer);
+               self
+       }
+
+       /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
+       /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
+       ///
+       /// Successive calls to this method will add another blinded path. Caller is responsible for not
+       /// adding duplicate paths.
+       pub fn path(mut self, path: BlindedPath) -> Self {
+               self.offer.paths.get_or_insert_with(Vec::new).push(path);
+               self
+       }
+
+       /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
+       /// [`Quantity::one`].
+       ///
+       /// Successive calls to this method will override the previous setting.
+       pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
+               self.offer.supported_quantity = quantity;
+               self
+       }
+
+       /// Builds an [`Offer`] from the builder's settings.
+       pub fn build(mut self) -> Result<Offer, SemanticError> {
+               match self.offer.amount {
+                       Some(Amount::Bitcoin { amount_msats }) => {
+                               if amount_msats > MAX_VALUE_MSAT {
+                                       return Err(SemanticError::InvalidAmount);
+                               }
+                       },
+                       Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
+                       None => {},
+               }
+
+               if let Some(chains) = &self.offer.chains {
+                       if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
+                               self.offer.chains = None;
+                       }
+               }
+
+               let mut bytes = Vec::new();
+               self.offer.write(&mut bytes).unwrap();
+
+               Ok(Offer {
+                       bytes,
+                       contents: self.offer,
+               })
+       }
+}
+
+#[cfg(test)]
+impl OfferBuilder {
+       fn features_unchecked(mut self, features: OfferFeatures) -> Self {
+               self.offer.features = features;
+               self
+       }
+}
+
 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 ///
-/// An offer is a precursor to an `InvoiceRequest`. A merchant publishes an offer from which a
+/// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 /// customer may request an `Invoice` for a specific quantity and using an amount sufficient to
 /// cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 ///
@@ -33,17 +232,21 @@ use std::time::SystemTime;
 /// latter.
 ///
 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
+///
+/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 #[derive(Clone, Debug)]
 pub struct Offer {
        // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
        // fields.
-       bytes: Vec<u8>,
-       contents: OfferContents,
+       pub(super) bytes: Vec<u8>,
+       pub(super) contents: OfferContents,
 }
 
-/// The contents of an [`Offer`], which may be shared with an `InvoiceRequest` or an `Invoice`.
+/// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or an `Invoice`.
+///
+/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 #[derive(Clone, Debug)]
-pub(crate) struct OfferContents {
+pub(super) struct OfferContents {
        chains: Option<Vec<ChainHash>>,
        metadata: Option<Vec<u8>>,
        amount: Option<Amount>,
@@ -52,7 +255,7 @@ pub(crate) struct OfferContents {
        absolute_expiry: Option<Duration>,
        issuer: Option<String>,
        paths: Option<Vec<BlindedPath>>,
-       quantity_max: Option<u64>,
+       supported_quantity: Quantity,
        signing_pubkey: Option<PublicKey>,
 }
 
@@ -64,10 +267,16 @@ impl Offer {
        /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
        /// for the selected chain.
        pub fn chains(&self) -> Vec<ChainHash> {
-               self.contents.chains
-                       .as_ref()
-                       .cloned()
-                       .unwrap_or_else(|| vec![ChainHash::using_genesis_block(Network::Bitcoin)])
+               self.contents.chains()
+       }
+
+       pub(super) fn implied_chain(&self) -> ChainHash {
+               self.contents.implied_chain()
+       }
+
+       /// Returns whether the given chain is supported by the offer.
+       pub fn supports_chain(&self, chain: ChainHash) -> bool {
+               self.contents.supports_chain(chain)
        }
 
        // TODO: Link to corresponding method in `InvoiceRequest`.
@@ -79,7 +288,7 @@ impl Offer {
 
        /// The minimum amount required for a successful payment of a single item.
        pub fn amount(&self) -> Option<&Amount> {
-               self.contents.amount.as_ref()
+               self.contents.amount()
        }
 
        /// A complete description of the purpose of the payment. Intended to be displayed to the user
@@ -126,22 +335,181 @@ impl Offer {
 
        /// The quantity of items supported.
        pub fn supported_quantity(&self) -> Quantity {
-               match self.contents.quantity_max {
-                       Some(0) => Quantity::Unbounded,
-                       Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
-                       None => Quantity::Bounded(NonZeroU64::new(1).unwrap()),
-               }
+               self.contents.supported_quantity()
+       }
+
+       /// Returns whether the given quantity is valid for the offer.
+       pub fn is_valid_quantity(&self, quantity: u64) -> bool {
+               self.contents.is_valid_quantity(quantity)
+       }
+
+       /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
+       ///
+       /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+       pub fn expects_quantity(&self) -> bool {
+               self.contents.expects_quantity()
        }
 
        /// The public key used by the recipient to sign invoices.
        pub fn signing_pubkey(&self) -> PublicKey {
                self.contents.signing_pubkey.unwrap()
        }
+
+       /// Creates an [`InvoiceRequest`] for the offer with the given `metadata` and `payer_id`, which
+       /// will be reflected in the `Invoice` response.
+       ///
+       /// The `metadata` is useful for including information about the derivation of `payer_id` such
+       /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
+       /// hashing in the signature calculation.
+       ///
+       /// This should not leak any information such as by using a simple BIP-32 derivation path.
+       /// Otherwise, payments may be correlated.
+       ///
+       /// Errors if the offer contains unknown required features.
+       ///
+       /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+       pub fn request_invoice(
+               &self, metadata: Vec<u8>, payer_id: PublicKey
+       ) -> Result<InvoiceRequestBuilder, SemanticError> {
+               if self.features().requires_unknown_bits() {
+                       return Err(SemanticError::UnknownRequiredFeatures);
+               }
+
+               Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
+       }
+
+       #[cfg(test)]
+       fn as_tlv_stream(&self) -> OfferTlvStreamRef {
+               self.contents.as_tlv_stream()
+       }
+}
+
+impl AsRef<[u8]> for Offer {
+       fn as_ref(&self) -> &[u8] {
+               &self.bytes
+       }
+}
+
+impl OfferContents {
+       pub fn chains(&self) -> Vec<ChainHash> {
+               self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
+       }
+
+       pub fn implied_chain(&self) -> ChainHash {
+               ChainHash::using_genesis_block(Network::Bitcoin)
+       }
+
+       pub fn supports_chain(&self, chain: ChainHash) -> bool {
+               self.chains().contains(&chain)
+       }
+
+       pub fn amount(&self) -> Option<&Amount> {
+               self.amount.as_ref()
+       }
+
+       pub(super) fn check_amount_msats_for_quantity(
+               &self, amount_msats: Option<u64>, quantity: Option<u64>
+       ) -> Result<(), SemanticError> {
+               let offer_amount_msats = match self.amount {
+                       None => 0,
+                       Some(Amount::Bitcoin { amount_msats }) => amount_msats,
+                       Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
+               };
+
+               if !self.expects_quantity() || quantity.is_some() {
+                       let expected_amount_msats = offer_amount_msats * quantity.unwrap_or(1);
+                       let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
+
+                       if amount_msats < expected_amount_msats {
+                               return Err(SemanticError::InsufficientAmount);
+                       }
+
+                       if amount_msats > MAX_VALUE_MSAT {
+                               return Err(SemanticError::InvalidAmount);
+                       }
+               }
+
+               Ok(())
+       }
+
+       pub fn supported_quantity(&self) -> Quantity {
+               self.supported_quantity
+       }
+
+       pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), SemanticError> {
+               let expects_quantity = self.expects_quantity();
+               match quantity {
+                       None if expects_quantity => Err(SemanticError::MissingQuantity),
+                       Some(_) if !expects_quantity => Err(SemanticError::UnexpectedQuantity),
+                       Some(quantity) if !self.is_valid_quantity(quantity) => {
+                               Err(SemanticError::InvalidQuantity)
+                       },
+                       _ => Ok(()),
+               }
+       }
+
+       fn is_valid_quantity(&self, quantity: u64) -> bool {
+               match self.supported_quantity {
+                       Quantity::Bounded(n) => {
+                               let n = n.get();
+                               if n == 1 { false }
+                               else { quantity > 0 && quantity <= n }
+                       },
+                       Quantity::Unbounded => quantity > 0,
+               }
+       }
+
+       fn expects_quantity(&self) -> bool {
+               match self.supported_quantity {
+                       Quantity::Bounded(n) => n.get() != 1,
+                       Quantity::Unbounded => true,
+               }
+       }
+
+       pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
+               let (currency, amount) = match &self.amount {
+                       None => (None, None),
+                       Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
+                       Some(Amount::Currency { iso4217_code, amount }) => (
+                               Some(iso4217_code), Some(*amount)
+                       ),
+               };
+
+               let features = {
+                       if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
+               };
+
+               OfferTlvStreamRef {
+                       chains: self.chains.as_ref(),
+                       metadata: self.metadata.as_ref(),
+                       currency,
+                       amount,
+                       description: Some(&self.description),
+                       features,
+                       absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
+                       paths: self.paths.as_ref(),
+                       issuer: self.issuer.as_ref(),
+                       quantity_max: self.supported_quantity.to_tlv_record(),
+                       node_id: self.signing_pubkey.as_ref(),
+               }
+       }
+}
+
+impl Writeable for Offer {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+               WithoutLength(&self.bytes).write(writer)
+       }
+}
+
+impl Writeable for OfferContents {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+               self.as_tlv_stream().write(writer)
+       }
 }
 
 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 /// another currency.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Amount {
        /// An amount of bitcoin.
        Bitcoin {
@@ -161,9 +529,701 @@ pub enum Amount {
 pub type CurrencyCode = [u8; 3];
 
 /// Quantity of items supported by an [`Offer`].
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum Quantity {
        /// Up to a specific number of items (inclusive).
        Bounded(NonZeroU64),
        /// One or more items.
        Unbounded,
 }
+
+impl Quantity {
+       /// The default quantity of one.
+       pub fn one() -> Self {
+               Quantity::Bounded(NonZeroU64::new(1).unwrap())
+       }
+
+       fn to_tlv_record(&self) -> Option<u64> {
+               match self {
+                       Quantity::Bounded(n) => {
+                               let n = n.get();
+                               if n == 1 { None } else { Some(n) }
+                       },
+                       Quantity::Unbounded => Some(0),
+               }
+       }
+}
+
+tlv_stream!(OfferTlvStream, OfferTlvStreamRef, 1..80, {
+       (2, chains: (Vec<ChainHash>, WithoutLength)),
+       (4, metadata: (Vec<u8>, WithoutLength)),
+       (6, currency: CurrencyCode),
+       (8, amount: (u64, HighZeroBytesDroppedBigSize)),
+       (10, description: (String, WithoutLength)),
+       (12, features: OfferFeatures),
+       (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
+       (16, paths: (Vec<BlindedPath>, WithoutLength)),
+       (18, issuer: (String, WithoutLength)),
+       (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
+       (22, node_id: PublicKey),
+});
+
+impl Bech32Encode for Offer {
+       const BECH32_HRP: &'static str = "lno";
+}
+
+impl FromStr for Offer {
+       type Err = ParseError;
+
+       fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
+               Self::from_bech32_str(s)
+       }
+}
+
+impl TryFrom<Vec<u8>> for Offer {
+       type Error = ParseError;
+
+       fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
+               let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
+               let ParsedMessage { bytes, tlv_stream } = offer;
+               let contents = OfferContents::try_from(tlv_stream)?;
+               Ok(Offer { bytes, contents })
+       }
+}
+
+impl TryFrom<OfferTlvStream> for OfferContents {
+       type Error = SemanticError;
+
+       fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
+               let OfferTlvStream {
+                       chains, metadata, currency, amount, description, features, absolute_expiry, paths,
+                       issuer, quantity_max, node_id,
+               } = tlv_stream;
+
+               let amount = match (currency, amount) {
+                       (None, None) => None,
+                       (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
+                               return Err(SemanticError::InvalidAmount);
+                       },
+                       (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
+                       (Some(_), None) => return Err(SemanticError::MissingAmount),
+                       (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
+               };
+
+               let description = match description {
+                       None => return Err(SemanticError::MissingDescription),
+                       Some(description) => description,
+               };
+
+               let features = features.unwrap_or_else(OfferFeatures::empty);
+
+               let absolute_expiry = absolute_expiry
+                       .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
+
+               let supported_quantity = match quantity_max {
+                       None => Quantity::one(),
+                       Some(0) => Quantity::Unbounded,
+                       Some(1) => return Err(SemanticError::InvalidQuantity),
+                       Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
+               };
+
+               if node_id.is_none() {
+                       return Err(SemanticError::MissingSigningPubkey);
+               }
+
+               Ok(OfferContents {
+                       chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
+                       supported_quantity, signing_pubkey: node_id,
+               })
+       }
+}
+
+impl core::fmt::Display for Offer {
+       fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
+               self.fmt_bech32_str(f)
+       }
+}
+
+#[cfg(test)]
+mod tests {
+       use super::{Amount, Offer, OfferBuilder, Quantity};
+
+       use bitcoin::blockdata::constants::ChainHash;
+       use bitcoin::network::constants::Network;
+       use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
+       use core::convert::TryFrom;
+       use core::num::NonZeroU64;
+       use core::time::Duration;
+       use crate::ln::features::OfferFeatures;
+       use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
+       use crate::offers::parse::{ParseError, SemanticError};
+       use crate::onion_message::{BlindedHop, BlindedPath};
+       use crate::util::ser::{BigSize, Writeable};
+       use crate::util::string::PrintableString;
+
+       fn pubkey(byte: u8) -> PublicKey {
+               let secp_ctx = Secp256k1::new();
+               PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
+       }
+
+       fn privkey(byte: u8) -> SecretKey {
+               SecretKey::from_slice(&[byte; 32]).unwrap()
+       }
+
+       #[test]
+       fn builds_offer_with_defaults() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               let mut buffer = Vec::new();
+               offer.write(&mut buffer).unwrap();
+
+               assert_eq!(offer.bytes, buffer.as_slice());
+               assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
+               assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
+               assert_eq!(offer.metadata(), None);
+               assert_eq!(offer.amount(), None);
+               assert_eq!(offer.description(), PrintableString("foo"));
+               assert_eq!(offer.features(), &OfferFeatures::empty());
+               assert_eq!(offer.absolute_expiry(), None);
+               #[cfg(feature = "std")]
+               assert!(!offer.is_expired());
+               assert_eq!(offer.paths(), &[]);
+               assert_eq!(offer.issuer(), None);
+               assert_eq!(offer.supported_quantity(), Quantity::one());
+               assert_eq!(offer.signing_pubkey(), pubkey(42));
+
+               assert_eq!(tlv_stream.chains, None);
+               assert_eq!(tlv_stream.metadata, None);
+               assert_eq!(tlv_stream.currency, None);
+               assert_eq!(tlv_stream.amount, None);
+               assert_eq!(tlv_stream.description, Some(&String::from("foo")));
+               assert_eq!(tlv_stream.features, None);
+               assert_eq!(tlv_stream.absolute_expiry, None);
+               assert_eq!(tlv_stream.paths, None);
+               assert_eq!(tlv_stream.issuer, None);
+               assert_eq!(tlv_stream.quantity_max, None);
+               assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
+
+               if let Err(e) = Offer::try_from(buffer) {
+                       panic!("error parsing offer: {:?}", e);
+               }
+       }
+
+       #[test]
+       fn builds_offer_with_chains() {
+               let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
+               let testnet = ChainHash::using_genesis_block(Network::Testnet);
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .chain(Network::Bitcoin)
+                       .build()
+                       .unwrap();
+               assert!(offer.supports_chain(mainnet));
+               assert_eq!(offer.chains(), vec![mainnet]);
+               assert_eq!(offer.as_tlv_stream().chains, None);
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .chain(Network::Testnet)
+                       .build()
+                       .unwrap();
+               assert!(offer.supports_chain(testnet));
+               assert_eq!(offer.chains(), vec![testnet]);
+               assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .chain(Network::Testnet)
+                       .chain(Network::Testnet)
+                       .build()
+                       .unwrap();
+               assert!(offer.supports_chain(testnet));
+               assert_eq!(offer.chains(), vec![testnet]);
+               assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .chain(Network::Bitcoin)
+                       .chain(Network::Testnet)
+                       .build()
+                       .unwrap();
+               assert!(offer.supports_chain(mainnet));
+               assert!(offer.supports_chain(testnet));
+               assert_eq!(offer.chains(), vec![mainnet, testnet]);
+               assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
+       }
+
+       #[test]
+       fn builds_offer_with_metadata() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .metadata(vec![42; 32])
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.metadata(), Some(&vec![42; 32]));
+               assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .metadata(vec![42; 32])
+                       .metadata(vec![43; 32])
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.metadata(), Some(&vec![43; 32]));
+               assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
+       }
+
+       #[test]
+       fn builds_offer_with_amount() {
+               let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
+               let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .amount_msats(1000)
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.amount(), Some(&bitcoin_amount));
+               assert_eq!(tlv_stream.amount, Some(1000));
+               assert_eq!(tlv_stream.currency, None);
+
+               let builder = OfferBuilder::new("foo".into(), pubkey(42))
+                       .amount(currency_amount.clone());
+               let tlv_stream = builder.offer.as_tlv_stream();
+               assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
+               assert_eq!(tlv_stream.amount, Some(10));
+               assert_eq!(tlv_stream.currency, Some(b"USD"));
+               match builder.build() {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, SemanticError::UnsupportedCurrency),
+               }
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .amount(currency_amount.clone())
+                       .amount(bitcoin_amount.clone())
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(tlv_stream.amount, Some(1000));
+               assert_eq!(tlv_stream.currency, None);
+
+               let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
+               match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
+               }
+       }
+
+       #[test]
+       fn builds_offer_with_features() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .features_unchecked(OfferFeatures::unknown())
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.features(), &OfferFeatures::unknown());
+               assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .features_unchecked(OfferFeatures::unknown())
+                       .features_unchecked(OfferFeatures::empty())
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.features(), &OfferFeatures::empty());
+               assert_eq!(offer.as_tlv_stream().features, None);
+       }
+
+       #[test]
+       fn builds_offer_with_absolute_expiry() {
+               let future_expiry = Duration::from_secs(u64::max_value());
+               let past_expiry = Duration::from_secs(0);
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .absolute_expiry(future_expiry)
+                       .build()
+                       .unwrap();
+               #[cfg(feature = "std")]
+               assert!(!offer.is_expired());
+               assert_eq!(offer.absolute_expiry(), Some(future_expiry));
+               assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .absolute_expiry(future_expiry)
+                       .absolute_expiry(past_expiry)
+                       .build()
+                       .unwrap();
+               #[cfg(feature = "std")]
+               assert!(offer.is_expired());
+               assert_eq!(offer.absolute_expiry(), Some(past_expiry));
+               assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
+       }
+
+       #[test]
+       fn builds_offer_with_paths() {
+               let paths = vec![
+                       BlindedPath {
+                               introduction_node_id: pubkey(40),
+                               blinding_point: pubkey(41),
+                               blinded_hops: vec![
+                                       BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
+                                       BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
+                               ],
+                       },
+                       BlindedPath {
+                               introduction_node_id: pubkey(40),
+                               blinding_point: pubkey(41),
+                               blinded_hops: vec![
+                                       BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
+                                       BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
+                               ],
+                       },
+               ];
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .path(paths[0].clone())
+                       .path(paths[1].clone())
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.paths(), paths.as_slice());
+               assert_eq!(offer.signing_pubkey(), pubkey(42));
+               assert_ne!(pubkey(42), pubkey(44));
+               assert_eq!(tlv_stream.paths, Some(&paths));
+               assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
+       }
+
+       #[test]
+       fn builds_offer_with_issuer() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .issuer("bar".into())
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.issuer(), Some(PrintableString("bar")));
+               assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .issuer("bar".into())
+                       .issuer("baz".into())
+                       .build()
+                       .unwrap();
+               assert_eq!(offer.issuer(), Some(PrintableString("baz")));
+               assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
+       }
+
+       #[test]
+       fn builds_offer_with_supported_quantity() {
+               let ten = NonZeroU64::new(10).unwrap();
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::one())
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.supported_quantity(), Quantity::one());
+               assert_eq!(tlv_stream.quantity_max, None);
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::Unbounded)
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
+               assert_eq!(tlv_stream.quantity_max, Some(0));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::Bounded(ten))
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
+               assert_eq!(tlv_stream.quantity_max, Some(10));
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::Bounded(ten))
+                       .supported_quantity(Quantity::one())
+                       .build()
+                       .unwrap();
+               let tlv_stream = offer.as_tlv_stream();
+               assert_eq!(offer.supported_quantity(), Quantity::one());
+               assert_eq!(tlv_stream.quantity_max, None);
+       }
+
+       #[test]
+       fn fails_requesting_invoice_with_unknown_required_features() {
+               match OfferBuilder::new("foo".into(), pubkey(42))
+                       .features_unchecked(OfferFeatures::unknown())
+                       .build().unwrap()
+                       .request_invoice(vec![1; 32], pubkey(43))
+               {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_chains() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .chain(Network::Bitcoin)
+                       .chain(Network::Testnet)
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_amount() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .amount(Amount::Bitcoin { amount_msats: 1000 })
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut tlv_stream = offer.as_tlv_stream();
+               tlv_stream.amount = Some(1000);
+               tlv_stream.currency = Some(b"USD");
+
+               let mut encoded_offer = Vec::new();
+               tlv_stream.write(&mut encoded_offer).unwrap();
+
+               if let Err(e) = Offer::try_from(encoded_offer) {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut tlv_stream = offer.as_tlv_stream();
+               tlv_stream.amount = None;
+               tlv_stream.currency = Some(b"USD");
+
+               let mut encoded_offer = Vec::new();
+               tlv_stream.write(&mut encoded_offer).unwrap();
+
+               match Offer::try_from(encoded_offer) {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount)),
+               }
+
+               let mut tlv_stream = offer.as_tlv_stream();
+               tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
+               tlv_stream.currency = None;
+
+               let mut encoded_offer = Vec::new();
+               tlv_stream.write(&mut encoded_offer).unwrap();
+
+               match Offer::try_from(encoded_offer) {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount)),
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_description() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut tlv_stream = offer.as_tlv_stream();
+               tlv_stream.description = None;
+
+               let mut encoded_offer = Vec::new();
+               tlv_stream.write(&mut encoded_offer).unwrap();
+
+               match Offer::try_from(encoded_offer) {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => {
+                               assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
+                       },
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_paths() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .path(BlindedPath {
+                               introduction_node_id: pubkey(40),
+                               blinding_point: pubkey(41),
+                               blinded_hops: vec![
+                                       BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
+                                       BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
+                               ],
+                       })
+                       .path(BlindedPath {
+                               introduction_node_id: pubkey(40),
+                               blinding_point: pubkey(41),
+                               blinded_hops: vec![
+                                       BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
+                                       BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
+                               ],
+                       })
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
+               builder.offer.paths = Some(vec![]);
+
+               let offer = builder.build().unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_quantity() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::one())
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::Unbounded)
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let offer = OfferBuilder::new("foo".into(), pubkey(42))
+                       .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
+                       .build()
+                       .unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut tlv_stream = offer.as_tlv_stream();
+               tlv_stream.quantity_max = Some(1);
+
+               let mut encoded_offer = Vec::new();
+               tlv_stream.write(&mut encoded_offer).unwrap();
+
+               match Offer::try_from(encoded_offer) {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => {
+                               assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidQuantity));
+                       },
+               }
+       }
+
+       #[test]
+       fn parses_offer_with_node_id() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
+               if let Err(e) = offer.to_string().parse::<Offer>() {
+                       panic!("error parsing offer: {:?}", e);
+               }
+
+               let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
+               builder.offer.signing_pubkey = None;
+
+               let offer = builder.build().unwrap();
+               match offer.to_string().parse::<Offer>() {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => {
+                               assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));
+                       },
+               }
+       }
+
+       #[test]
+       fn fails_parsing_offer_with_extra_tlv_records() {
+               let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
+
+               let mut encoded_offer = Vec::new();
+               offer.write(&mut encoded_offer).unwrap();
+               BigSize(80).write(&mut encoded_offer).unwrap();
+               BigSize(32).write(&mut encoded_offer).unwrap();
+               [42u8; 32].write(&mut encoded_offer).unwrap();
+
+               match Offer::try_from(encoded_offer) {
+                       Ok(_) => panic!("expected error"),
+                       Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
+               }
+       }
+}
+
+#[cfg(test)]
+mod bech32_tests {
+       use super::{Offer, ParseError};
+       use bitcoin::bech32;
+       use crate::ln::msgs::DecodeError;
+
+       // TODO: Remove once test vectors are updated.
+       #[ignore]
+       #[test]
+       fn encodes_offer_as_bech32_without_checksum() {
+               let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
+               let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
+               let reencoded_offer = offer.to_string();
+               dbg!(reencoded_offer.parse::<Offer>().unwrap());
+               assert_eq!(reencoded_offer, encoded_offer);
+       }
+
+       // TODO: Remove once test vectors are updated.
+       #[ignore]
+       #[test]
+       fn parses_bech32_encoded_offers() {
+               let offers = [
+                       // BOLT 12 test vectors
+                       "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+                       "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+                       "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+                       "lno1qcp4256ypqpq+86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qs+y",
+                       "lno1qcp4256ypqpq+ 86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+  0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+\nsqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43l+\r\nastpwuh73k29qs+\r  y",
+                       // Two blinded paths
+                       "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",
+               ];
+               for encoded_offer in &offers {
+                       if let Err(e) = encoded_offer.parse::<Offer>() {
+                               panic!("Invalid offer ({:?}): {}", e, encoded_offer);
+                       }
+               }
+       }
+
+       #[test]
+       fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
+               let offers = [
+                       // BOLT 12 test vectors
+                       "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+",
+                       "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+ ",
+                       "+lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+                       "+ lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+                       "ln++o1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
+               ];
+               for encoded_offer in &offers {
+                       match encoded_offer.parse::<Offer>() {
+                               Ok(_) => panic!("Valid offer: {}", encoded_offer),
+                               Err(e) => assert_eq!(e, ParseError::InvalidContinuation),
+                       }
+               }
+
+       }
+
+       #[test]
+       fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
+               let encoded_offer = "lni1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
+               match encoded_offer.parse::<Offer>() {
+                       Ok(_) => panic!("Valid offer: {}", encoded_offer),
+                       Err(e) => assert_eq!(e, ParseError::InvalidBech32Hrp),
+               }
+       }
+
+       #[test]
+       fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
+               let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qso";
+               match encoded_offer.parse::<Offer>() {
+                       Ok(_) => panic!("Valid offer: {}", encoded_offer),
+                       Err(e) => assert_eq!(e, ParseError::Bech32(bech32::Error::InvalidChar('o'))),
+               }
+       }
+
+       #[test]
+       fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
+               let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsyqqqqq";
+               match encoded_offer.parse::<Offer>() {
+                       Ok(_) => panic!("Valid offer: {}", encoded_offer),
+                       Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
+               }
+       }
+}