refactor(client)!: relay_fee result should be strongly typed

src/api.rs

@@ -4,7 +4,7 @@ use std::borrow::Borrow;
 use std::convert::TryInto;
 
 use bitcoin::consensus::encode::{deserialize, serialize};
-use bitcoin::{block, Script, Transaction, Txid};
+use bitcoin::{block, Amount, Script, Transaction, Txid};
 
 use crate::batch::Batch;
 use crate::types::*;
@@ -97,8 +97,8 @@ pub trait ElectrumApi {
     /// Estimates the fee required in **Bitcoin per kilobyte** to confirm a transaction in `number` blocks.
     fn estimate_fee(&self, number: usize) -> Result<f64, Error>;
 
-    /// Returns the minimum accepted fee by the server's node in **Bitcoin, not Satoshi**.
-    fn relay_fee(&self) -> Result<f64, Error>;
+    /// Returns the minimum accepted fee by the server's node.
+    fn relay_fee(&self) -> Result<Amount, Error>;
 
     /// Subscribes to notifications for activity on a specific *scriptPubKey*.
     ///

src/client.rs

@@ -4,7 +4,7 @@ use std::{borrow::Borrow, sync::RwLock};
 
 use log::{info, warn};
 
-use bitcoin::{Script, Txid};
+use bitcoin::{Amount, Script, Txid};
 
 use crate::api::ElectrumApi;
 use crate::batch::Batch;
@@ -212,7 +212,7 @@ impl ElectrumApi for Client {
     }
 
     #[inline]
-    fn relay_fee(&self) -> Result<f64, Error> {
+    fn relay_fee(&self) -> Result<Amount, Error> {
         impl_inner_call!(self, relay_fee)
     }
 

src/raw_client.rs

@@ -17,7 +17,7 @@ use log::{debug, error, info, trace, warn};
 
 use bitcoin::consensus::encode::deserialize;
 use bitcoin::hex::{DisplayHex, FromHex};
-use bitcoin::{Script, Txid};
+use bitcoin::{Amount, Script, Txid};
 
 #[cfg(feature = "use-openssl")]
 use openssl::ssl::{SslConnector, SslMethod, SslStream, SslVerifyMode};
@@ -879,17 +879,18 @@ impl<T: Read + Write> ElectrumApi for RawClient<T> {
             .ok_or_else(|| Error::InvalidResponse(result.clone()))
     }
 
-    fn relay_fee(&self) -> Result<f64, Error> {
+    fn relay_fee(&self) -> Result<Amount, Error> {
         let req = Request::new_id(
             self.last_id.fetch_add(1, Ordering::SeqCst),
             "blockchain.relayfee",
             vec![],
         );
         let result = self.call(req)?;
 
-        result
+        let amount_float = result
             .as_f64()
-            .ok_or_else(|| Error::InvalidResponse(result.clone()))
+            .ok_or_else(|| Error::InvalidResponse(result.clone()))?;
+        Amount::from_btc(amount_float).map_err(|_| Error::InvalidResponse(result.clone()))
     }
 
     fn script_subscribe(&self, script: &Script) -> Result<Option<ScriptStatus>, Error> {