feat: wait for confirmations in WaitBlock (#2416)

pkg/node/chain.go

@@ -30,8 +30,9 @@ import (
 )
 
 const (
-	maxDelay          = 1 * time.Minute
-	cancellationDepth = 6
+	maxDelay                = 1 * time.Minute
+	cancellationDepth       = 6
+	additionalConfirmations = 2
 )
 
 // InitChain will initialize the Ethereum backend at the given endpoint and
@@ -293,13 +294,7 @@ func GetTxNextBlock(ctx context.Context, logger logging.Logger, backend transact
 		return blockHash, nil
 	}
 
-	// if not found in statestore, fetch from chain
-	tx, err := backend.TransactionReceipt(ctx, common.BytesToHash(trx))
-	if err != nil {
-		return nil, err
-	}
-
-	block, err := transaction.WaitBlock(ctx, backend, duration, big.NewInt(0).Add(tx.BlockNumber, big.NewInt(1)))
+	block, err := transaction.WaitBlockAfterTransaction(ctx, backend, duration, common.BytesToHash(trx), additionalConfirmations)
 	if err != nil {
 		return nil, err
 	}

pkg/transaction/backend.go

@@ -76,15 +76,33 @@ func WaitSynced(ctx context.Context, logger logging.Logger, backend Backend, max
 	}
 }
 
-func WaitBlock(ctx context.Context, backend Backend, pollingInterval time.Duration, block *big.Int) (*types.Header, error) {
+func WaitBlockAfterTransaction(ctx context.Context, backend Backend, pollingInterval time.Duration, txHash common.Hash, additionalConfirmations uint64) (*types.Header, error) {
 	for {
-		header, err := backend.HeaderByNumber(ctx, block)
+		receipt, err := backend.TransactionReceipt(ctx, txHash)
 		if err != nil {
 			if !errors.Is(err, ethereum.NotFound) {
 				return nil, err
 			}
-		} else {
-			return header, nil
+			continue
+		}
+
+		bn, err := backend.BlockNumber(ctx)
+		if err != nil {
+			return nil, err
+		}
+
+		nextBlock := receipt.BlockNumber.Uint64() + 1
+
+		if bn >= nextBlock+additionalConfirmations {
+			header, err := backend.HeaderByNumber(ctx, new(big.Int).SetUint64(nextBlock))
+			if err != nil {
+				if !errors.Is(err, ethereum.NotFound) {
+					return nil, err
+				}
+				// in the case where we cannot find the block even though we already saw a higher number we keep on trying
+			} else {
+				return header, nil
+			}
 		}
 
 		select {