Adding missing Block Tip Hash API

backend/src/api/bitcoin/bitcoin-api-abstract-factory.ts

@@ -4,6 +4,7 @@ export interface AbstractBitcoinApi {
   $getRawMempool(): Promise<IEsploraApi.Transaction['txid'][]>;
   $getRawTransaction(txId: string, skipConversion?: boolean, addPrevout?: boolean, lazyPrevouts?: boolean): Promise<IEsploraApi.Transaction>;
   $getBlockHeightTip(): Promise<number>;
+  $getBlockHashTip(): Promise<string>;
   $getTxIdsForBlock(hash: string): Promise<string[]>;
   $getBlockHash(height: number): Promise<string>;
   $getBlockHeader(hash: string): Promise<string>;

backend/src/api/bitcoin/bitcoin-api.ts

@@ -64,6 +64,13 @@ class BitcoinApi implements AbstractBitcoinApi {
       });
   }
 
+  $getBlockHashTip(): Promise<string> {
+    return this.bitcoindClient.getChainTips()
+      .then((result: IBitcoinApi.ChainTips[]) => {
+        return result.find(tip => tip.status === 'active')!.hash;
+      });
+  }
+
   $getTxIdsForBlock(hash: string): Promise<string[]> {
     return this.bitcoindClient.getBlock(hash, 1)
       .then((rpcBlock: IBitcoinApi.Block) => rpcBlock.tx);

backend/src/api/bitcoin/esplora-api.ts

@@ -25,6 +25,11 @@ class ElectrsApi implements AbstractBitcoinApi {
       .then((response) => response.data);
   }
 
+  $getBlockHashTip(): Promise<string> {
+    return axios.get<string>(config.ESPLORA.REST_API_URL + '/blocks/tip/hash', this.axiosConfig)
+      .then((response) => response.data);
+  }
+
   $getTxIdsForBlock(hash: string): Promise<string[]> {
     return axios.get<string[]>(config.ESPLORA.REST_API_URL + '/block/' + hash + '/txids', this.axiosConfig)
       .then((response) => response.data);