Merge bitcoindevkit/bdk-ffi#150: Add new BumpFeeTxBuilder interface

0787d9c446a3390f0e020dcabd5f30a9d760391d Fix order of BumpFeeTxBuilder parameters (Steve Myers)
390d12703eb12fc3b58a14f62a64f8582ebbeaf2 Change TxBuilder and BumpFeeTxBuilder build() to finish() (Steve Myers)
9f903932dc59e1cc955112492b699330b8806d93 Add BumpFeeTxBuilder (Steve Myers)

Pull request description:

  Add BumpFeeTxBuilder to bump the fee on an unconfirmed tx created by the Wallet. The structure of the new interface is:

  ```udl
  interface BumpFeeTxBuilder {
    constructor(string txid, float new_fee_rate);
    BumpFeeTxBuilder allow_shrinking(string address);
    BumpFeeTxBuilder enable_rbf();
    BumpFeeTxBuilder enable_rbf_with_sequence(u32 nsequence);
    [Throws=BdkError]
    PartiallySignedBitcoinTransaction build([ByRef] Wallet wallet);
  };
  ```
  Fixes #150

Top commit has no ACKs.

Tree-SHA512: a24ed41f7b897a0e091ef55d4c1347b3973cbe628b7d1bd69c95e663bc6f049de8f7e3b019115d763cff3fa6d5cb4d31ed474022c3087e8404a2af37f380d56d

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 - Update BDK to version 0.18.0
+- Add BumpFeeTxBuilder to bump the fee on an unconfirmed tx created by the Wallet
+- Change TxBuilder.build() to TxBuilder.finish() to align with bdk function name 
 
 ## [v0.5.0]
 

src/bdk.udl

@@ -155,7 +155,16 @@ interface TxBuilder {
   TxBuilder enable_rbf();
   TxBuilder enable_rbf_with_sequence(u32 nsequence);
   [Throws=BdkError]
-  PartiallySignedBitcoinTransaction build([ByRef] Wallet wallet);
+  PartiallySignedBitcoinTransaction finish([ByRef] Wallet wallet);
+};
+
+interface BumpFeeTxBuilder {
+  constructor(string txid, float new_fee_rate);
+  BumpFeeTxBuilder allow_shrinking(string address);
+  BumpFeeTxBuilder enable_rbf();
+  BumpFeeTxBuilder enable_rbf_with_sequence(u32 nsequence);
+  [Throws=BdkError]
+  PartiallySignedBitcoinTransaction finish([ByRef] Wallet wallet);
 };
 
 dictionary ExtendedKeyInfo {

src/lib.rs

@@ -1,7 +1,7 @@
 use bdk::bitcoin::hashes::hex::ToHex;
 use bdk::bitcoin::secp256k1::Secp256k1;
 use bdk::bitcoin::util::psbt::PartiallySignedTransaction;
-use bdk::bitcoin::{Address, Network, Script};
+use bdk::bitcoin::{Address, Network, Script, Txid};
 use bdk::blockchain::any::{AnyBlockchain, AnyBlockchainConfig};
 use bdk::blockchain::{
     electrum::ElectrumBlockchainConfig, esplora::EsploraBlockchainConfig, ConfigurableBlockchain,
@@ -406,7 +406,7 @@ impl TxBuilder {
         })
     }
 
-    fn build(&self, wallet: &Wallet) -> Result<Arc<PartiallySignedBitcoinTransaction>, Error> {
+    fn finish(&self, wallet: &Wallet) -> Result<Arc<PartiallySignedBitcoinTransaction>, Error> {
         let wallet = wallet.get_wallet();
         let mut tx_builder = wallet.build_tx();
         for (address, amount) in &self.recipients {
@@ -440,4 +440,78 @@ impl TxBuilder {
     }
 }
 
+struct BumpFeeTxBuilder {
+    txid: String,
+    fee_rate: f32,
+    allow_shrinking: Option<String>,
+    rbf: Option<RbfValue>,
+}
+
+impl BumpFeeTxBuilder {
+    fn new(txid: String, fee_rate: f32) -> Self {
+        Self {
+            txid,
+            fee_rate,
+            allow_shrinking: None,
+            rbf: None,
+        }
+    }
+
+    fn allow_shrinking(&self, address: String) -> Arc<Self> {
+        Arc::new(Self {
+            txid: self.txid.clone(),
+            fee_rate: self.fee_rate,
+            allow_shrinking: Some(address),
+            rbf: self.rbf.clone(),
+        })
+    }
+
+    fn enable_rbf(&self) -> Arc<Self> {
+        Arc::new(Self {
+            txid: self.txid.clone(),
+            fee_rate: self.fee_rate,
+            allow_shrinking: self.allow_shrinking.clone(),
+            rbf: Some(RbfValue::Default),
+        })
+    }
+
+    fn enable_rbf_with_sequence(&self, nsequence: u32) -> Arc<Self> {
+        Arc::new(Self {
+            txid: self.txid.clone(),
+            fee_rate: self.fee_rate,
+            allow_shrinking: self.allow_shrinking.clone(),
+            rbf: Some(RbfValue::Value(nsequence)),
+        })
+    }
+
+    fn finish(&self, wallet: &Wallet) -> Result<Arc<PartiallySignedBitcoinTransaction>, Error> {
+        let wallet = wallet.get_wallet();
+        let txid = Txid::from_str(self.txid.as_str())?;
+        let mut tx_builder = wallet.build_fee_bump(txid)?;
+        tx_builder.fee_rate(FeeRate::from_sat_per_vb(self.fee_rate));
+        if let Some(allow_shrinking) = &self.allow_shrinking {
+            let address =
+                Address::from_str(allow_shrinking).map_err(|e| Error::Generic(e.to_string()))?;
+            let script = address.script_pubkey();
+            tx_builder.allow_shrinking(script)?;
+        }
+        if let Some(rbf) = &self.rbf {
+            match *rbf {
+                RbfValue::Default => {
+                    tx_builder.enable_rbf();
+                }
+                RbfValue::Value(nsequence) => {
+                    tx_builder.enable_rbf_with_sequence(nsequence);
+                }
+            }
+        }
+        tx_builder
+            .finish()
+            .map(|(psbt, _)| PartiallySignedBitcoinTransaction {
+                internal: Mutex::new(psbt),
+            })
+            .map(Arc::new)
+    }
+}
+
 uniffi::deps::static_assertions::assert_impl_all!(Wallet: Sync, Send);