Fix same age inputs being ordered differently

chains/btc/mempool/mempool.go

@@ -77,7 +77,11 @@ func (a *MempoolAPI) Utxos(address string) ([]Utxo, error) {
 		return nil, err
 	}
 	sort.Slice(utxos, func(i int, j int) bool {
-		return utxos[i].Status.BlockTime < utxos[j].Status.BlockTime
+		if utxos[i].Status.BlockTime == utxos[j].Status.BlockTime {
+			return utxos[i].TxID < utxos[j].TxID
+		} else {
+			return utxos[i].Status.BlockTime < utxos[j].Status.BlockTime
+		}
 	})
 
 	return utxos, nil

chains/btc/mempool/mempool_test.go

@@ -60,6 +60,17 @@ func (s *MempoolTestSuite) Test_Utxo_SuccessfulFetch() {
 				BlockTime:   1715083122,
 			},
 		},
+		{
+			TxID:  "28154e2008912d27978225c096c22ffe2ea65e1d55bf440ee41c21f9489c7fe2",
+			Vout:  0,
+			Value: 11197,
+			Status: mempool.Status{
+				Confirmed:   true,
+				BlockHeight: 2812826,
+				BlockHash:   "000000000000001a01d4058773384f2c23aed5a7e5ede252f99e290fa58324a3",
+				BlockTime:   1715083122,
+			},
+		},
 		{
 			TxID:  "28154e2008912d27978225c096c22ffe2ea65e1d55bf440ee41c21f9489c7fe9",
 			Vout:  0,

chains/btc/mempool/test-data/successful-utxo.json

@@ -1,4 +1,5 @@
 [
     {"txid":"28154e2008912d27978225c096c22ffe2ea65e1d55bf440ee41c21f9489c7fe9","vout":0,"status":{"confirmed":true,"block_height":2812827,"block_hash":"000000000000001a01d4058773384f2c23aed5a7e5ede252f99e290fa58324a5","block_time":1715083123},"value":11198},
+    {"txid":"28154e2008912d27978225c096c22ffe2ea65e1d55bf440ee41c21f9489c7fe2","vout":0,"status":{"confirmed":true,"block_height":2812826,"block_hash":"000000000000001a01d4058773384f2c23aed5a7e5ede252f99e290fa58324a3","block_time":1715083122},"value":11197},
     {"txid":"28154e2008912d27978225c096c22ffe2ea65e1d55bf440ee41c21f9489c7fe1","vout":0,"status":{"confirmed":true,"block_height":2812826,"block_hash":"000000000000001a01d4058773384f2c23aed5a7e5ede252f99e290fa58324a3","block_time":1715083122},"value":11197}
 ]