feat: remove unused fee output

sn_transfers/src/cashnotes/builder.rs

@@ -8,8 +8,8 @@
 
 use super::{
     transaction::{Output, Transaction},
-    CashNote, DerivationIndex, DerivedSecretKey, FeeOutput, Hash, Input, MainPubkey, NanoTokens,
-    SignedSpend, Spend, UniquePubkey,
+    CashNote, DerivationIndex, DerivedSecretKey, Hash, Input, MainPubkey, NanoTokens, SignedSpend,
+    Spend, UniquePubkey,
 };
 
 use crate::{Error, Result};
@@ -25,7 +25,6 @@ pub type InputSrcTx = Transaction;
 pub struct TransactionBuilder {
     inputs: Vec<Input>,
     outputs: Vec<Output>,
-    fee: FeeOutput,
     input_details: BTreeMap<UniquePubkey, (DerivedSecretKey, InputSrcTx)>,
     output_details: BTreeMap<UniquePubkey, (MainPubkey, DerivationIndex)>,
 }
@@ -83,18 +82,11 @@ impl TransactionBuilder {
         self
     }
 
-    /// Sets the given fee output.
-    pub fn set_fee_output(mut self, output: FeeOutput) -> Self {
-        self.fee = output;
-        self
-    }
-
     /// Build the Transaction by signing the inputs. Return a CashNoteBuilder.
     pub fn build(self, reason: Hash) -> Result<CashNoteBuilder> {
         let spent_tx = Transaction {
             inputs: self.inputs.clone(),
             outputs: self.outputs.clone(),
-            fee: self.fee.clone(),
         };
         let signed_spends: BTreeSet<_> = self
             .inputs

sn_transfers/src/cashnotes/cashnote.rs

@@ -7,8 +7,8 @@
 // permissions and limitations relating to use of the SAFE Network Software.
 
 use super::{
-    DerivationIndex, DerivedSecretKey, FeeOutput, Hash, MainPubkey, MainSecretKey, NanoTokens,
-    SignedSpend, Transaction, UniquePubkey,
+    DerivationIndex, DerivedSecretKey, Hash, MainPubkey, MainSecretKey, NanoTokens, SignedSpend,
+    Transaction, UniquePubkey,
 };
 
 use crate::{Error, Result};
@@ -99,11 +99,6 @@ impl CashNote {
         self.derivation_index
     }
 
-    /// Return the fee output used in the source transaction
-    pub fn fee_output(&self) -> &FeeOutput {
-        &self.src_tx.fee
-    }
-
     /// Return the reason why this CashNote was spent.
     /// Will be the default Hash (empty) if reason is none.
     pub fn reason(&self) -> Hash {

sn_transfers/src/cashnotes/mod.rs

@@ -9,15 +9,13 @@
 mod address;
 mod builder;
 mod cashnote;
-mod fee_output;
 mod nano;
 mod reason_hash;
 mod signed_spend;
 mod transaction;
 mod unique_keys;
 
 pub(crate) use builder::TransactionBuilder;
-pub(crate) use fee_output::FeeOutput;
 pub(crate) use transaction::Input;
 
 pub use address::SpendAddress;
@@ -44,7 +42,6 @@ pub(crate) mod tests {
         let tx = Transaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.unique_pubkey(), amount)],
-            fee: FeeOutput::new(Hash::default(), 3_500, Hash::default()),
         };
         let cashnote = CashNote {
             id: derived_key.unique_pubkey(),
@@ -59,9 +56,6 @@ pub(crate) mod tests {
         let cashnote = CashNote::from_hex(&hex)?;
         assert_eq!(cashnote.value()?.as_nano(), 1_530_000_000);
 
-        let fee_amount = cashnote.fee_output().token;
-        assert_eq!(fee_amount, NanoTokens::from(3_500));
-
         Ok(())
     }
 
@@ -75,7 +69,6 @@ pub(crate) mod tests {
         let tx = Transaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.unique_pubkey(), amount)],
-            fee: FeeOutput::new(Hash::default(), 2_500, Hash::default()),
         };
         let cashnote = CashNote {
             id: derived_key.unique_pubkey(),
@@ -90,9 +83,6 @@ pub(crate) mod tests {
 
         assert_eq!(cashnote.value()?, cashnote_from_hex.value()?);
 
-        let fee_amount = cashnote.fee_output().token;
-        assert_eq!(fee_amount, NanoTokens::from(2_500));
-
         Ok(())
     }
 
@@ -108,7 +98,6 @@ pub(crate) mod tests {
         let tx = Transaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.unique_pubkey(), amount)],
-            fee: FeeOutput::default(),
         };
 
         let cashnote = CashNote {
@@ -140,7 +129,6 @@ pub(crate) mod tests {
         let tx = Transaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.unique_pubkey(), amount)],
-            fee: FeeOutput::default(),
         };
 
         let cashnote = CashNote {

sn_transfers/src/cashnotes/transaction.rs

@@ -4,7 +4,7 @@
 // This SAFE Network Software is licensed under the BSD-3-Clause license.
 // Please see the LICENSE file for more details.
 
-use super::{FeeOutput, NanoTokens, SignedSpend, UniquePubkey};
+use super::{NanoTokens, SignedSpend, UniquePubkey};
 use serde::{Deserialize, Serialize};
 use std::{cmp::Ordering, collections::BTreeSet};
 use tiny_keccak::{Hasher, Sha3};
@@ -69,7 +69,6 @@ impl Output {
 pub struct Transaction {
     pub inputs: Vec<Input>,
     pub outputs: Vec<Output>,
-    pub fee: FeeOutput,
 }
 
 impl PartialEq for Transaction {
@@ -97,7 +96,6 @@ impl Transaction {
         Self {
             inputs: vec![],
             outputs: vec![],
-            fee: FeeOutput::default(),
         }
     }
 
@@ -111,8 +109,6 @@ impl Transaction {
         for o in self.outputs.iter() {
             v.extend(&o.to_bytes());
         }
-        v.extend("fee".as_bytes());
-        v.extend(&self.fee.to_bytes());
         v.extend("end".as_bytes());
         v
     }
@@ -156,7 +152,6 @@ impl Transaction {
             .outputs
             .iter()
             .map(|o| o.amount)
-            .chain(std::iter::once(self.fee.token))
             .try_fold(0, |acc: u64, o| {
                 acc.checked_add(o.as_nano()).ok_or(Error::NumericOverflow)
             })?;

sn_transfers/src/lib.rs

@@ -15,7 +15,7 @@ mod genesis;
 mod transfers;
 mod wallet;
 
-pub(crate) use cashnotes::{FeeOutput, Input, TransactionBuilder};
+pub(crate) use cashnotes::{Input, TransactionBuilder};
 
 /// Types used in the public API
 pub use cashnotes::{

sn_transfers/src/transfers/offline_transfer.rs

@@ -7,8 +7,8 @@
 // permissions and limitations relating to use of the SAFE Network Software.
 
 use crate::{
-    rng, CashNote, DerivationIndex, DerivedSecretKey, FeeOutput, Hash, Input, MainPubkey,
-    NanoTokens, SignedSpend, Transaction, TransactionBuilder, UniquePubkey,
+    rng, CashNote, DerivationIndex, DerivedSecretKey, Hash, Input, MainPubkey, NanoTokens,
+    SignedSpend, Transaction, TransactionBuilder, UniquePubkey,
 };
 use crate::{Error, Result};
 
@@ -88,7 +88,7 @@ pub fn create_offline_transfer(
         change: (change_amount, change_to),
     };
 
-    create_offline_transfer_with(selected_inputs, reason_hash, None)
+    create_offline_transfer_with(selected_inputs, reason_hash)
 }
 
 /// Select the necessary number of cash_notes from those that we were passed.
@@ -161,7 +161,6 @@ fn select_inputs(
 fn create_offline_transfer_with(
     selected_inputs: TranferInputs,
     reason_hash: Hash,
-    fee: Option<FeeOutput>,
 ) -> Result<OfflineTransfer> {
     let TranferInputs {
         change: (change, change_to),
@@ -190,10 +189,6 @@ fn create_offline_transfer_with(
         .add_inputs(inputs)
         .add_outputs(selected_inputs.recipients);
 
-    if let Some(fee_output) = fee {
-        tx_builder = tx_builder.set_fee_output(fee_output);
-    }
-
     let mut rng = rng::thread_rng();
     let derivation_index = UniquePubkey::random_derivation_index(&mut rng);
     let change_id = change_to.new_unique_pubkey(&derivation_index);