feat: use FeeRate type in TxBuilder

bdk-ffi/src/bdk.udl

@@ -68,7 +68,14 @@ dictionary TxOut {
 // ------------------------------------------------------------------------
 
 interface FeeRate {
+  [Name=from_sat_per_vb]
+  constructor(f32 sat_per_vb);
+
+  [Name=from_sat_per_kwu]
+  constructor(f32 sat_per_kwu);
+
   f32 as_sat_per_vb();
+
   f32 sat_per_kwu();
 };
 
@@ -132,7 +139,7 @@ interface TxBuilder {
 
   TxBuilder manually_selected_only();
 
-  TxBuilder fee_rate(float sat_per_vbyte);
+  TxBuilder fee_rate([ByRef] FeeRate fee_rate);
 
   TxBuilder fee_absolute(u64 fee);
 

bdk-ffi/src/types.rs

@@ -11,9 +11,18 @@ use bdk::FeeRate as BdkFeeRate;
 
 use std::sync::Arc;
 
+#[derive(Clone, Debug)]
 pub struct FeeRate(pub BdkFeeRate);
 
 impl FeeRate {
+    pub fn from_sat_per_vb(sat_per_vb: f32) -> Self {
+        FeeRate(BdkFeeRate::from_sat_per_vb(sat_per_vb))
+    }
+
+    pub fn from_sat_per_kwu(sat_per_kwu: f32) -> Self {
+        FeeRate(BdkFeeRate::from_sat_per_kwu(sat_per_kwu))
+    }
+
     pub fn as_sat_per_vb(&self) -> f32 {
         self.0.as_sat_per_vb()
     }

bdk-ffi/src/wallet.rs

@@ -309,7 +309,7 @@ pub struct TxBuilder {
     pub(crate) unspendable: HashSet<OutPoint>,
     pub(crate) change_policy: ChangeSpendPolicy,
     pub(crate) manually_selected_only: bool,
-    pub(crate) fee_rate: Option<f32>,
+    pub(crate) fee_rate: Option<FeeRate>,
     pub(crate) fee_absolute: Option<u64>,
     pub(crate) drain_wallet: bool,
     pub(crate) drain_to: Option<BdkScriptBuf>,
@@ -412,9 +412,9 @@ impl TxBuilder {
         })
     }
 
-    pub(crate) fn fee_rate(&self, sat_per_vb: f32) -> Arc<Self> {
+    pub(crate) fn fee_rate(&self, fee_rate: &FeeRate) -> Arc<Self> {
         Arc::new(TxBuilder {
-            fee_rate: Some(sat_per_vb),
+            fee_rate: Some(fee_rate.clone()),
             ..self.clone()
         })
     }
@@ -486,8 +486,8 @@ impl TxBuilder {
         if self.manually_selected_only {
             tx_builder.manually_selected_only();
         }
-        if let Some(sat_per_vb) = self.fee_rate {
-            tx_builder.fee_rate(BdkFeeRate::from_sat_per_vb(sat_per_vb));
+        if let Some(fee_rate) = &self.fee_rate {
+            tx_builder.fee_rate(fee_rate.0);
         }
         if let Some(fee_amount) = self.fee_absolute {
             tx_builder.fee_absolute(fee_amount);