pass errors up rather than logging directly

providers/bitcoinElectrum/bitcoin.go

@@ -3,7 +3,7 @@ package bitcoinElectrum
 import (
 	"crypto/sha256"
 	"encoding/hex"
-	"log"
+	"fmt"
 	"sync/atomic"
 
 	"github.com/btcsuite/btcd/btcutil"
@@ -43,13 +43,10 @@ func addressToScriptHash(address btcutil.Address) (string, error) {
 }
 
 // Scans a derivation branch (m/0 or m/1) for balances until the gap limit is reached.
-func scanBranch(masterKey *hdkeychain.ExtendedKey, branch uint32, gapLimit int, spvServer string) int64 {
-	log.Printf("Scanning branch m/%d/k...", branch)
-
+func scanBranch(masterKey *hdkeychain.ExtendedKey, branch uint32, gapLimit int, spvServer string) (int64, error) {
 	branchKey, err := masterKey.Derive(branch)
 	if err != nil {
-		log.Printf("Error deriving branch %d: %v", branch, err)
-		return 0
+		return 0, fmt.Errorf("error deriving branch %d: %v", branch, err)
 	}
 
 	var branchTotalBalance int64
@@ -57,35 +54,28 @@ func scanBranch(masterKey *hdkeychain.ExtendedKey, branch uint32, gapLimit int,
 
 	for i := uint32(0); ; i++ {
 		if unusedAddressCount >= gapLimit {
-			log.Printf("Gap limit of %d reached on branch m/%d. Stopping scan.", gapLimit, branch)
 			break
 		}
 
 		// 3. Derive child address
 		address, err := deriveAddress(branchKey, i)
 		if err != nil {
-			log.Printf("Could not derive address at index %d on branch %d: %v", i, branch, err)
-			continue
+			return 0, fmt.Errorf("could not derive address at index %d on branch %d: %v", i, branch, err)
 		}
 
 		// 4. Get balance from Electrum server
 		balance, err := getAddressBalance(spvServer, address)
 		if err != nil {
-			log.Printf("Error getting balance for %s: %v", address.EncodeAddress(), err)
-			// On error, we can't know if it's used, so we continue scanning.
-			unusedAddressCount = 0
-			continue
+			return 0, fmt.Errorf("error getting balance for %s: %v", address.EncodeAddress(), err)
 		}
 
 		total := balance.Result.Confirmed + balance.Result.Unconfirmed
 		if total > 0 {
-			log.Printf("Found balance for m/%d/%d (%s): %.8f BTC", branch, i, address.EncodeAddress(), btcutil.Amount(total).ToBTC())
 			atomic.AddInt64(&branchTotalBalance, total)
 			unusedAddressCount = 0 // Reset gap counter on finding a used address
 		} else {
-			log.Printf("No balance for m/%d/%d (%s)", branch, i, address.EncodeAddress())
 			unusedAddressCount++
 		}
 	}
-	return branchTotalBalance
+	return branchTotalBalance, nil
 }