feat: add broadcast method on electrum client

bdk-ffi/src/bdk.udl

@@ -501,6 +501,9 @@ interface ElectrumClient {
 
   [Throws=ElectrumClientError]
   Update sync(SyncRequest sync_request, u64 batch_size, boolean fetch_prev_txouts);
+
+  [Throws=ElectrumClientError]
+  string broadcast([ByRef] Transaction transaction);
 };
 
 // ------------------------------------------------------------------------

bdk-ffi/src/electrum.rs

@@ -3,14 +3,16 @@ use crate::types::{FullScanRequest, SyncRequest};
 use crate::wallet::Update;
 use std::collections::BTreeMap;
 
+use bdk::bitcoin::Transaction as BdkTransaction;
 use bdk::chain::spk_client::FullScanRequest as BdkFullScanRequest;
 use bdk::chain::spk_client::FullScanResult as BdkFullScanResult;
 use bdk::chain::spk_client::SyncRequest as BdkSyncRequest;
 use bdk::chain::spk_client::SyncResult as BdkSyncResult;
 use bdk::KeychainKind;
-use bdk_electrum::electrum_client::Client as BdkBlockingClient;
+use bdk_electrum::electrum_client::{Client as BdkBlockingClient, ElectrumApi};
 use bdk_electrum::{ElectrumExt, ElectrumFullScanResult, ElectrumSyncResult};
 
+use crate::bitcoin::Transaction;
 use std::sync::Arc;
 
 pub struct ElectrumClient(BdkBlockingClient);
@@ -82,4 +84,12 @@ impl ElectrumClient {
 
         Ok(Arc::new(Update(update)))
     }
+
+    pub fn broadcast(&self, transaction: &Transaction) -> Result<String, ElectrumClientError> {
+        let bdk_transaction: BdkTransaction = transaction.into();
+        self.0
+            .transaction_broadcast(&bdk_transaction)
+            .map_err(ElectrumClientError::from)
+            .map(|txid| txid.to_string())
+    }
 }